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2014 NEC Instructors Manual and Student Worksheets – Level 2 1
2014
ELECTRICAL INSPECTOR
INSTRUCTORS’ MANUAL
LEVEL II
NC Code Officials Qualification Board
322 Chapanoke Road
Raleigh, NC 27603
2014 NEC Instructors Manual and Student Worksheets – Level 2 2
ARTICLE TITLE PAGE TM
100 DEFINITIONS 70-27 4 110 REQUIREMENTS FOR ELECTRICAL INSTALLATIONS 70-36 7 220 BRANCH CIRCUIT, FEEDER AND SERVICE CALCULATIONS 70-66 11 225 OUTSIDE BRANCH CIRCUITS AND FEEDERS 70-76 17 240 OVERCURRENT PROTECTION 70-94 22 250 GROUNDING AND BONDING 70-106 25 310 CONDUCTORS FOR GENERAL WIRING 70-154 28 320 ARMORED CABLE : TYPE AC 70-193 33 324 FLAT CONDUCTOR CABLE: TYPE FCC 70-196 36 332 MINERAL-INSULATED, METAL-SHEATHED CABLE: TYPE MI 70-202 39 360 FLEXIBLE METALLIC TUBING: TYPE FMT 70-226 42
362 ELECTRICAL NONMETALLIC TUBING: TYPE ENT 70-227 45 368 BUSWAYS 70-231 48 370 CABLEBUS 70-234 51 372 CELLULAR CONCRETE FLOOR RACEWAYS 70-235 54 374 CELLULAR METAL FLOOR RACEWAYS 70-236 57 376 METAL WIREWAYS 70-237 60 378 NONMETALLIC WIREWAYS 70-239 60 382 NONMETALLIC EXTENSIONS 70-240 63 390 UNDERFLOOR RACEWAYS 70-246 66 396 MESSENGER-SUPPORTED WIRING 70-258 70 398 OPEN WIRING ON INSULATORS 70-259 72 424 FIXED ELECTRIC SPACE-HEATING EQUIPMENT 70-308 75 426 FIXED OUTDOOR ELECTRIC DEICING AND
SNOW-MELTING EQUIPMENT 70-317 85
430 MOTORS, MOTOR CIRCUITS, AND CONTROLLERS 70-323 90 450 TRANSFORMERS AND TRANSFORMER VAULTS 70-360 96 460 CAPACITORS 70-370 99 480 STORAGE BATTERIES 70-372 102 510 HAZARDOUS (CLASSIFIED) LOCATIONS —SPECIFIC 70-437 105 511 COMMERCIAL GARAGES, REPAIR AND STORAGE 70-437 108
520 THEATERS, AUDIENCE AREAS OF MOTION PICTURE AND TELEVISION STUDIOS, PERFORMANCE AREAS, AND SIMILAR LOCATIONS
70-482 111
522 CONTROL SYSTEMS FOR PERMANENT AMUSEMENT ATTRACTIONS
70-491 116 525 CARNIVALS, CIRCUSES, FAIRS, AND SIMILAR
EVENTS 70-493 119
540 MOTION PICTURE PROJECTION ROOMS 70-499 122 555 MARINAS AND BOATYARDS 70-536 126
604 MANUFACTURED WIRING SYSTEMS 70-549 131
620 ELEVATORS, DUMBWAITERS, ESCALATORS, MOVING WALKS, PLATFORM LIFTS, AND STAIRWAY CHAIRLIFTS
70-557 134
625 ELECTRIC VEHICLE CHARGING SYSTEM 70-567 139
630 ELECTRIC WELDERS 70-577 142
LEVEL II
TABLE OF CONTENTS BY ARTICLES
2014 NEC Instructors Manual and Student Worksheets – Level 2 3
640 AUDIO SIGNAL PROCESSING, AMPLIFICATION,
AND REPRODUCTION EQUIPMENT 70-579 154
645 INFORMATION TECHNOLOGY EQUIPMENT 70-584 148
650 PIPE ORGANS 70-593 151 670 INDUSTRIAL MACHINERY 70-601 154 675 ELECTRICALLY DRIVEN OR CONTROLLED
IRRIGATION MACHINES 70-602 158
685 INTEGRATED ELECTRICAL SYSTEMS 70-622 162
695 FIRE PUMPS 70-646 165
700 EMERGENCY SYSTEMS 70-652 169
701 LEGALLY REQUIRED STANDBY SYSTEMS 70-657 175 702 OPTIONAL STANDBY SYSTEMS 70-661 179
708 CRITICAL OPERATIONS POWER SYSTEMS (COPS) 70-667 182 720 CIRCUITS AND EQUIPMENT OPERATING AT LESS THAN 50 VOLTS 70-672 185
725 CLASS 1, CLASS 2 AND CLASS 3 REMOTE-CONTROL , SIGNALING, AND POWER-LIMITED CIRCUITS
70-672 188
727 INSTRUMENTATION TRAY CABLE: TYPE ITC 70-685 192 760 FIRE ALARM SYSTEMS 70-688 195 770 OPTICAL FIBER CABLES AND RACEWAYS 70-669 200 800 COMMUNICATIONS CIRCUITS 70-709 203 810 RADIO AND TELEVISION EQUIPMENT 70-725 206
820 COMMUNITY ANTENNA TELEVISION AND RADIO DISTRIBUTION SYSTEMS
70-729 209
THE PAGE NUMBER LISTED ABOVE CORRESPONDS TO THE ARTICLE LOCATION IN THE NORTH CAROLINA
ELECTRIC CODE BOOK (THE NEC 2014). THE “TM” NUMBERS TO THE RIGHT OF THE ARTICLE NUMBERS
CORRESPONDS TO THE PAGE NUMBERS IN THE TRAINING MANUAL FOR THE STARTING PAGE FOR EACH
ARTICLE LISTED.
2014 NEC Instructors Manual and Student Worksheets – Level 2 4
DEFINITIONS
ARTICLE 100
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with definitions essential to
the proper use of the National Electrical Code.
INTRODUCTION:
This lesson should give the inspector a clear definition of terms used in the National
Electrical Code. The definitions included in Article 100 are terms used in two or more
articles of the Code. Definitions specific to only one article are given in that article.
PRESENTING THE LESSON:
The current edition of the National Electrical Code is used. The instructor should lead a
class discussion on definitions, giving illustrations of the definitions.
Example:
Switches:
Transfer switch - a device for transferring one or more load conductor connections from
one power source to another.
(Show examples with slides or on chalkboard in class, using actual materials if available).
APPLICATION:
If time will allow, have the students answer the questions on the worksheet.
CHECKING AND FOLLOW-UP
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 5
DEFINITIONS
ARTICLE 100
Level II
WORKSHEET
1. Which of the following is a device, group of devices, or other means whereby the
conductors of a circuit can be disconnected from their source of supply?
a. A thermal overload device.
b. A disconnecting means.
c. A fuse.
d. A switch.
2. Which of the following best describes a multifamily dwelling?
a. A building that contains dwelling units.
b. A building that contains two dwelling units.
c. A building that contains two or more dwelling units.
d. A building that contains three or more dwelling units.
3. A continuous load is a load expected to exist for which of the following?
a. 1 hour or more
b. 2 hours or more
c. 3 hours or more
d. 4 hours or more
2014 NEC Instructors Manual and Student Worksheets – Level 2 6
DEFINITIONS
ARTICLE 100
Level II
ANSWER KEY
1. b. a disconnecting means 100
2. d. 3 or more - see dwelling multi-family 100
3. c - 3 hours or more 100
2014 NEC Instructors Manual and Student Worksheets – Level 2 7
REQUIREMENTS FOR ELECTRICAL INSTALLATIONS
ARTICLE 110
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the general requirements
of the National Electrical Code for electrical installation.
INTRODUCTION:
This Article contains general requirements for all electrical installations including listing of
equipment, access and working space and temperature limitations.
PRESENTING THE LESSON:
110.3(B)
Many times inspectors are called upon to judge the suitability of equipment in situations
not covered in the NEC. In these situations 110.3(B) gives the necessary guidance required
to make intelligent choices.
Installation and Use. Listed or labeled equipment shall be used or installed in accordance
with any instructions included in the listing or labeling.
NCGS 66.25 requires all electric equipment to be listed.
The instructor should cover the various booklets published by testing laboratories, calling
attention to the general information included i.e. : UL Whitebook.
110.13(B)
Stress cooling where ambient temperatures must be maintained due to the equipment
limitations, characteristics, or listing.
110.14(C)
The temperature limitations of conductors selected are based on the circuit ampacity of 100
Amperes or less, or greater than 100 amperes.
110.22
Stress the importance of identifying disconnecting means as required in 110.22. This
marking allows prompt and accurate disconnection for servicing equipment in time of
emergency.
110.26(C)(2)
2014 NEC Instructors Manual and Student Worksheets – Level 2 8
Larger access and working spaces are required for equipment rated 1200 amperes or more
and over 6 feet wide.
110.30
Conductors and equipment used on circuits over 600 volts must meet more stringent
requirements than those under 600 volts. 110.31 covers measurements required for
properly protecting the public and those required to service the equipment. The instructor
should point out the different means of protection for qualified and unqualified persons
both indoors and outdoors. Many outdoor overhead installations are not covered by the
NEC but a Fine Print Note refers us to the National Electrical Safety Code.
110.32
The instructor should point out differences in work space, guarding and entrance and
access for 600 volts or less (110.26) and over 600 volts 110.30 through 110.34. Where
equipment is located in a room or enclosure, suitable barriers must be installed to separate
high voltage and low voltage equipment.
110.34(C)
It is very important that rooms or enclosures containing exposed live parts be kept locked.
The access doors must be properly marked with warning signs.
APPLICATION:
If time will allow, have the students answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 9
REQUIREMENTS FOR ELECTRICAL INSTALLATIONS
ARTICLE 110
Level II
WORKSHEET
1. Equipment must be installed:
a. According to Code only
b. According to listing and labeling of equipment
c. The way the inspector wants.
d. The way the owner wants.
2. Each disconnecting means required by the NEC shall be:
a. Marked at its point of origin
b. Marked to indicate its purpose
c. Marked in a permanent manner
d. Marked by all of the above
3. The minimum clear working space required between the front of a 277/480V,
switchboard and a concrete wall is which of the following?
a. 3 feet
b. 3.5 feet
c. 4 feet
d. 5 feet
4. Illumination shall be provided for all working spaces about service equipment installed
in which of the following locations?
a. dwelling units
b. commercial buildings
c. in industrial buildings
d. all of the above
5. In a new panel board installation, the minimum headroom clearance shall be which of the
following?
a. 6 feet
b. 6 ½ feet
c. 3 feet
d. 5 feet
2014 NEC Instructors Manual and Student Worksheets – Level 2 10
REQUIREMENTS FOR ELECTRICAL INSTALLATIONS
ARTICLE 110
Level II
ANSWER KEY
1. b, according to listing and labeling of equipment 110.3(B)
2. d, all of the above 110.22(A)
3. b, 3.5 Table 110.26(A)(1)
4. d, all of the above 110.26(D)
5. b, 6 ½ feet 110.26(E)
2014 NEC Instructors Manual and Student Worksheets – Level 2 11
BRANCH CIRCUIT AND FEEDER CALCULATIONS
ARTICLE 220
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the requirements for
determining the number of branch circuits required and for computing branch circuit and
feeder loads using different voltages, and ratings.
INTRODUCTION:
This lesson should introduce the student to basic electrical formulas and methods used to
determine sizes of branch circuits and feeders. Explain to class that you will cover
requirements for calculations of branch circuits, feeders and services. Make sure that class
knows the difference in residential and commercial applications.
PRESENTING THE LESSON:
Review Article 220 level I in the NEC. Briefly review the lesson on residential
requirements for feeders and branch circuits and their calculations. Then, cover the
commercial application for branch circuits and feeder services. Give examples using table
220.12.
Note: V/A per square meter on table.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 12
BRANCH CIRCUIT AND FEEDER CALCULATIONS
ARTICLE 220
Level II
WORKSHEET
1. Which of the following is the minimum number of 120 volt, 2 wire, 15 amp, branch circuits
for the general lighting loads for a 2100 square foot single family dwelling?
a. 3
b. 4
c. 5
d. 6
2. A 20 KW, 240 volt, 3-phase, continuous load is to be served with THW copper. Which of
the following is the minimum size conductor permitted for the load?
a. 3
b. 4
c. 5
d. 6
3. A 30 KW, 208 volt, 3-phase, continuous load is to be supplied with 75° C copper
conductors. Which of the following is the minimum size conductor permitted for the load?
a. 4
b. 2
c. 1
d. 3
4. Sign and outline lighting outlets shall be calculated at what minimum volt-amperes for each
required branch circuit specified in 600.5(A).
a. 1200
b. 1400
c. 1600
d. 1800
2014 NEC Instructors Manual and Student Worksheets – Level 2 13
5. A 120/240 volt, 3 wire feeder is to serve eight household electric clothes dryers rated at 5
KW. Using Article 220.54, what is the minimum volt amperes required for this feeder?
a. 16,800 volt amperes
b. 24,000 volt amperes
c. 28,000 volt amperes
d. 40,000 volt amperes
6. Fixed electric space heating loads shall be calculated at what percent of the total connected
load.
a. 60 percent
b. 80 percent
c. 100 percent
d. 125 percent
7. An installation has a total linear load of 500 amperes. Which of the following is the
minimum size ampacity of the neutral conductor?
a. 350 amp
b. 500 amp
c. 410 amp
d. 300 amp
8. Compute the Load for a 5000 sq. ft. store building with 90 duplex general purpose
receptacles, 50 feet of show window and a 20 ampere sign circuit. Service is 120/208 volt
3 phase.
a. 127 amperes
b. 220 amperes
c. 191 amperes
d. 300 amperes
9. If THW copper conductors are used, what is the minimum size service-entrance conductors
required?
a. 350 kcmil
b. 3/0
c. 4/0
d. # 1
2014 NEC Instructors Manual and Student Worksheets – Level 2 14
10. A new all electric restaurant has a total connected load of 260 KVA. Compute the load
using the optional calculation. Determine the minimum size of the service entrance
conductors if THW copper conductors are used. Voltage is 480/277 volt 3 phase.
a. 500 kcmil
b. 4/0
c. 3/0 kcmil
d. 250 kcmil
2014 NEC Instructors Manual and Student Worksheets – Level 2 15
BRANCH CIRCUIT AND FEEDER CALCULATIONS
ARTICLE 220
Level II
ANSWER KEY
1. b, (2,100 x 3) / 120 / 15 = 3.5 = 4 circuits
220.12
2. d, (20,000 x 1.25) / 1.732 / 240 = 60.14 (Table 310.15(B)(16) use #6 THW Cu.)
220.19(A)(1), 310.15(A)(1), Table 310.15(B)(16)
3. b, (30,000 x 1.25) / 1.732 / 208 = 104.09 amps (Table 310.16 use #2 THW Cu)
220.19(A)(1), 310.15(A)(1), Table 310.15(B)(16)
4. a, 220.14 (F)
5. b, (8 x 5000 x .6) = 24,000 (Table 220.54)
6. c, 100, 220.51
7. b, 500 amp (220.61)
8. a, 127 amperes (230.42(A))
Gen. Lighting 5,000 X 3 = 15,000 (220.12)
Show Window 50 X 200 = 10,000 (220.43)
Sign 1,200 (220.14(F))
26,200
x 1.25 (230.42(A)(1))
32,750 continuous load
Receptacles 90 X 180 = 16,200 (220.44)
- 10,000 (at 100%)
6,200
x .50 Demand
3,100
+10,000
13,100 VA Non-continuous.
Total 32,750 + 13,100 = 45,850
45,850/(208 x 1.732) = 127 amp
9. d, #1 (230.42(A)(1), Table 310.15(B)(16))
10. c, 3/0 (220.88)
2014 NEC Instructors Manual and Student Worksheets – Level 2 16
STORE BUILDING Example
A 1400 sq. ft. store building has 25 ft. of show window. There are 30 duplex receptacles. Ten,
120 volt light fixtures rated at 260 volt-amperes each are installed. A 20 ampere outside sign
circuit is provided. Computed the minimum allowable ampacity of the service conductors if a
120/240 volt single phase service is used.
NONCONTINUOUS LOADS
Receptacle Load
30 receptacles at 180 VA = 5,400 VA total............5,400 VA
(Insufficient load for 220-44 Demand factor)
CONTINUOUS LOADS
1400 sq. ft. X 3 VA................................................................................4200 VA
(10 lights X 260 VA = 2600 VA)
Show Window 25 ft. X 200 VA...............................................……….5000 VA
TOTAL CONTINUOUS LOAD.............................9,200 VA
X 1.25
11,500 VA
Outside Sign per Section 600-5(b)(3) 1200 VA
plus noncontinuous load......................... +5400 VA
TOTAL CONTINUOUS & NONCONTINUOUS...........…….18,100 VA
18,100/240 Volts = 75.42 (round to 75 amperes)
2014 NEC Instructors Manual and Student Worksheets – Level 2 17
OUTSIDE BRANCH CIRCUITS AND FEEDERS
ARTICLE 225
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with electrical equipment and
wiring located on the outside of buildings, structures or poles on the premises served.
INTRODUCTION:
Outside branch circuits are typically those circuits located on the exterior of buildings
and/or structures. This Article covers many aspects of outside wiring such as load
calculations, conductor coverings and sizes, minimum conductor size, overcurrent
protection and more. One typical place you might find this outside wiring is in business
areas such as parking lots. There are many other Articles in the Code that deal with outside
circuits and they should also be consulted when the need arises. One such example might
be the wiring around a swimming pool.
PRESENTING THE LESSON:
In order to determine the load on outdoor branch circuits you should consult with Section
220.12. Also, the load on outdoor feeders shall comply with Part II of Article 220.
Where open wiring on insulators is within 10 feet of buildings it shall be covered or
insulated. See Section 225.4 for different types of coverings (Rubber Covered or
Thermoplastic) for various situations.
See Tables 310.15 (B)(16)through 310.60 (C)(86) for information on conductor sizes.
When lighting equipment is installed outdoors, the branch-circuits shall comply with
Article 210 and 225.7(B through D).
The Feeder or branch-circuit disconnecting means shall have a rating of not less than the
calculated load to be supplied, determined in accordance with Parts I and II of Article 220
for branch circuit, Part III or IV of Article 220 for feeders, or Part V of Article 220 for farm
loads.
The restrictions on wiring for outside wiring surfaces of buildings are covered in Section
225.10. When dealing with circuit entrances and exits, see the requirements listed in
230.52
See Table 230.51(C) for open conductor spacings. Open conductors of different circuits
shall be separated by not less than 4 inches. For information on the separation of
conductors on poles see Section 225.14(D).
2014 NEC Instructors Manual and Student Worksheets – Level 2 18
Supports over buildings see Section 230.29, points of attachment see Section 230.26, , and
means of attachment are covered in Section 230.27. Ground clearances are outlined in
Section 225.18.
Horizontal clearances shall not be less than 3 feet. Final spans of feeders or branch circuits
to a building shall be permitted to be attached to the building if kept 3 feet from windows,
doors, porches, fire escapes or similar locations; however, when conductors run above a
window it shall be permitted to be less than 3 feet. See Section 225.19(E) for clearances in
zones for fire ladders.
Other various Articles should be consulted concerning mechanical protection and
multiconductor cables and raceways on exterior surfaces of buildings. Underground circuits
shall comply with Section 300.5.
Outdoor lampholders when attached as pendants, the connection shall be staggered. Also,
if terminals that puncture the insulation of conductors are used to make contact, they should
only be used on stranded type conductors. See Section 225.25 for location of outdoor
lamps.
Live vegetation, such as trees may not be used to support overhead conductor spans.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 19
OUTSIDE BRANCH CIRCUITS AND FEEDERS
ARTICLE 225
Level II
WORKSHEET
1. When without messenger wires, overhead conductors for festoon lighting shall not be
smaller than which of the following?
a. (a) # 14
b. (b) #12
c. (c) #10
d. (d) #8
2. Open conductors on insulators shall be insulated or covered, if they are installed within
how many feet of a building or other structure?
a. 10 feet
b. 12 feet
c. 15 feet
d. 18 feet
3. Conductors run above the top level of a window shall be permitted to be at which of the
following?
a. Less than 3 feet from the window.
b. Less than 5 feet from the window.
c. Less than 2 feet from the window.
d. Less than 6 feet from the window.
4. Where buildings exceed three stories or 50 ft. in height, overhead lines shall be arranged,
where practicable, so that a clear space (or zone) at least which of the following distance will
be left adjacent to the building?
a. 6 ft. wide
b. 3 ft. wide
c. 8 feet wide
d. 7 feet wide
2014 NEC Instructors Manual and Student Worksheets – Level 2 20
5. Open conductors shall be separated from open conductors of other circuits or systems by
not less than which of the following distance?
a. 3 inches
b. 5 inches
c. 6 inches
d. 4 inches
2014 NEC Instructors Manual and Student Worksheets – Level 2 21
OUTSIDE BRANCH CIRCUITS AND FEEDERS
ARTICLE 225
Level II
ANSWER KEY
1. b, #12 225.6(B)
2. a, 10 feet 225.4
3. a, less 225.19(D)(1) exception
4. c. 6 feet 225.19 (E)
5. d, 4 inches 225.14 (C)
2014 NEC Instructors Manual and Student Worksheets – Level 2 22
OVERCURRENT PROTECTION
ARTICLE 240
LEVEL II
OBJECTIVE:
After completing this lesson, each student should be familiar with the requirements of
Section 240.13 and 240.4(B) & (C).
INTRODUCTION:
This lesson should introduce the inspector to the requirements for overcurrent devices rated
800 amperes and ground protection of equipment.
PRESENTING THE LESSON:
Provide a complete clarification and explanation of 240.4 (D) small conductors and the
relation of size and ampacity ratings. Indicate the standard Ampere ratings of fuses and
fixed-trip circuit breakers and cover the ratings. Explain the difference in the requirement
for conductors being fed from overcurrent devices rated 800 amperes or less or from
overcurrent devices rated above 800 amperes. Explain the ground fault requirement for
solidly grounded wye electrical systems of more than 150 volts to ground, but not
exceeding 600 volts phase to phase and the main disconnect rated 100 amperes or above.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING THE FOLLOW-UP:
If time will allow, correct the worksheet and discuss results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 23
OVERCURRENT PROTECTION
ARTICLE 240
LEVEL II
WORKSHEET
1. The next higher standard overcurrent device rating (above the ampacity of the conductors
being protected) shall be permitted to be used, provided:
(a) The conductors being protected are not part of a multioutlet branch circuit
supplying receptacles for cord and- plug-connected portable loads.
(b) The ampacity of the conductors does not correspond with the standard ampere
rating of a fuse or a circuit breaker without overload trip adjustments above its
rating (but that shall be permitted to have other trip or rating adjustments).
(c) The next higher standard rating selected does not exceed 800 amperes.
(d) All of the above
2. Ground-fault protection of equipment is required for solidly grounded wye systems of more
than 150 volts to ground but not exceeding 600 volts phase to phase for each building or
structure main disconnect rated at which of the following?
(a) 800 amperes or more.
(b) 1,000 amperes or more.
(c) 600 volts or more.
(d) 300 volts to ground.
3. Which of the following statements is true about Edison-base type Plug fuses?
I- shall be used only for replacements in existing installations where there is
no evidence of overfusing or tampering.
II- fuse holder will only accept the correct rated fuse
a. I only
b. II only
c. both I & II
d. neither
2014 NEC Instructors Manual and Student Worksheets – Level 2 24
OVERCURRENT PROTECTION
ARTICLE 240
LEVEL II
ANSWER KEY
1. d, all of the above 240.4(C)
2. b, 1000 amperes 240.13
3. a, I only 240.51
2014 NEC Instructors Manual and Student Worksheets – Level 2 25
GROUNDING
ARTICLE 250
LEVEL II
OBJECTIVE:
After completing this lesson, each student should be familiar with the requirements of
250.30(B), Grounding Separately Derived Alternating-Current Systems., and 250.66, Sizes
of Alternating-Current Grounding Electrode Conductor.
INTRODUCTION:
This lesson should familiarize the student with the necessary uses of the grounded
conductor.
PRESENTING THE LESSON:
Provide a detailed opening starting with the scope 250.1 and the relation to Figure 250.1.
You will need to provide details of all 9 parts as it is related to Grounding and Bonding to
help eliminate the confusion between the two. Once the group has the understanding of
Grounding and Bonding, then you can go over the article. Review Article 250 of Level I in
the NEC. Briefly review the information in 250.30 and 250.66. Give example of different
grounding electrodes that are permitted in 250.52 and what is not permitted. Give
examples using Table 250.66. Show how the table is used when sizing conductors without
over current protection. Show Table 250.122 and how it is used when you have an
overcurrent protection before the conductor.
APPLICATION:
If time will allow, let the students answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 26
GROUNDING
ARTICLE 250
LEVEL II
WORKSHEET
1. Where the service entrance phase conductors are paralleled:
A. The size of the grounded conductor shall be based on total circular mill area
of the parallel conductors.
B. The size shall be based on the equivalent area for parallel conductors.
a. A only
b. B only
c. Both A and B above
d. Neither A nor B above
2. The service entrance conductors for a 120/280 volt, 3 phase, 4 wire system is # 4/0 Cu.
What shall be the grounding electrode conductor size for this installation?
a. #4
b. #2
c. #1/0
d. #2/0
3. A grounding electrode conductor that is the sole connection to the grounding electrode as
permitted in 250.52(A)(5) or (A)(7) shall not be required to be larger than:
a. # 6 Cu. or # 4 Al.
b. # 8 AL or # 10 Cu.
c. # 10 Al or # 12 Cu.
d. # 4 Cu. or # 2 Al
2014 NEC Instructors Manual and Student Worksheets – Level 2 27
GROUNDING
ARTICLE 250
LEVEL II
ANSWER KEY
1. (a) a only 250.24(C)(2)
2. (b) # 2 250.66 Table
3. (a) # 6 Cu. or # 4 AL 250.66(A)
2014 NEC Instructors Manual and Student Worksheets – Level 2 28
CONDUCTORS FOR GENERAL WIRING
ARTICLE 310
Level II
OBJECTIVE:
Each student should be familiar with conductors for general wiring in high voltage
applications.
INTRODUCTION:
Wiring methods utilized in applications where the voltage exceeds 600 volts require
specialized conductors with appropriate insulation, especially when operating at voltages
exceeding 2000 volts. At these higher voltages it is essential that proper conductors be used
for the application and extreme care must be exercised to install these conductors as
specified by their listing and NEC provisions. This will help to insure the safest possible
installation.
MATERIALS NEEDED :
Samples of conductors with different voltages, shielded conductors and cables, etc.
PRESENTING THE LESSON:
Review Level 1 Lesson Plans.
Define High Voltage – Over 600 Volts nominal except for grounding which is over 1 KV –
Article 490, 250. Minimum insulation level for neutral conductors of a solidly grounded
high voltage system is 600 Volts. [250.184]
Ampacities of Conductors Rated 2001 to 35,000 Volts for solid dielectric-insulated
conductors shall be permitted to be determined by tables or under engineering
supervision, as provided in 310.60(B) and (C).
Shielding is required and insulation shields must be grounded when using solid dielectric
insulated conductors or direct burial conductors or cables when voltage in either case
exceeds 2000 volts. The purpose of shielding is to confine the voltage stresses to the
insulation. Insulation shields shall be connected to a grounding electrode conductor,
grounding busbar, or a grounding electrode. [310.10(E) & 310.60(B)(1)]
Conductors must be marked as required by 310.120.
Discuss briefly the application of Tables 310.15(B)(16) through 310.60(C)(86) and the
accompanying notes. Tables 310.15(B)(16) through 310.15(B)(21) apply only up through
2000 volts.
2014 NEC Instructors Manual and Student Worksheets – Level 2 29
Emphasize the importance of reading the table headings carefully to determine the
applicability.
Use ampacity correction factors for Table 310.15(B)(2)(a) & 310.15(B)(2)(b) to briefly
discuss how ambient temperature affects conductor ampacity.
Table 310.15(B)(2)(a) is for ampacity Tables 310.15(B)(16) & 310.15(B)(17) for ambient
temperature of 30 degrees C.
Table 310.15(B)(2)(b) is for Tables 310.15(B)(18) through 310.(B)(21) for ambient
temperature of 40 degrees C.
NOTE: When applying the notes to Tables 310.60(C)(67) through 310.60(C)(86) it would
be advisable to seek assistance from a qualified engineer.
APPLICATION:
If time will allow, let the class time answer questions on the worksheet.
CHECKING AND FOLLOW UP :
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 30
CONDUCTORS FOR GENERAL WIRING
ARTICLE 310
WORKSHEET
1. In general, what is the largest solid conductor that may be installed in raceway?
a. #8
b. #10
c. #12
d. #6
2. In general, which is the smallest conductor that may be paralleled?
a. 2/0
b. 1/0
c. 3/0
d. any size
3. Which of the following is not true about paralleled conductors?
a. They shall be the same length.
b. They shall be the same size in circular mil area.
c. They may be different insulation types.
d. They shall have the same conductor material.
4. All of the following may be used in wet locations except:
a. THW
b. THHN
c. THWN
d. RHW
5. What is the ampacity of three #2 THW copper conductors installed in a raceway when the
ambient temperature is 48 degrees Celsius?
a. 100 amperes
b. 86 amps
c. 95 amperes
d. 110 amps
2014 NEC Instructors Manual and Student Worksheets – Level 2 31
6. What is the maximum over-current device that may be installed on a #12 THHN copper
conductor when there are 30 current carrying conductors installed in the same raceway?
a. 15 amps
b. 20 amps
c. 10 amps
d. 30 amps
7. A 120/208 volt 3 Phase 4 wire feeder is installed in a raceway to supply a 24,000 VA
fluorescent lighting load. This THW copper wire will pass through an ambient temperature
of 100 degrees Fahrenheit. What is the minimum size wire that could be used for this
feeder?
a. # 3
b. # 4
c. # 6
d. # 2
8. A 120/240 volt 1 Phase branch circuit is installed in a raceway to supply a 10,000 VA
water heater, 100 gallons. This THW copper wire will pass through an ambient
temperature of 100 degrees F. What is the minimum size wire that could be used for this
branch circuit?
a. # 8
b. # 6
c. # 4
d. # 3
9. A dwelling has a 120/240 volt 300 AMP service. What would be the minimum size THW
copper wire that could be used for this service?
a. 300 KC-MIL
b. 350 KC-MIL
c. 500 KC-MIL
d. 250 KC-MIL
10. A store has a 120/208 volt 3 Phase 200 AMP service. What would be the minimum size
THW Copper Wire that could be used for this service?
a. 2/0
b. 4/0
c. 3/0
d. 1/0
2014 NEC Instructors Manual and Student Worksheets – Level 2 32
CONDUCTORS FOR GENERAL WIRING
ARTICLE 310
ANSWER KEY
1. b 310.106(C)
2. b 310.10(H)(1)
3. c shall be of the same type insulation 310.10(H)(2)
4. b, THHN 310.10(C)
5. b 115a X .75 = 86.25a Tb.310.15(B)(16), Tb.310.15(B)(2)(a), Tb.240.4(B),240.6
6. a 30a X .45 = 13.5a Tb.310.15(B)(16), Tb. 310.15(B)(3)(a) Tb 240.4(B),240.6
7. a 24,000/360 = 67a/.88=75.75a/.80= 94.6a Tb. 310.15(B)(16), Tb. 310.15(B)(2)(a),
Tb. 310.15(B)(3)(a), 310.15(B)(5)
8. b 10,000/240 =41.6a X 125% = 52a/.88=59a Table 310.15(B)(16) ,422-13
9. d 300a X .83 = 249a 310.15(B)(7)
10. c Table 310.15(B)(16)
2014 NEC Instructors Manual and Student Worksheets – Level 2 33
ARMORED CABLE
ARTICLE 320
Level II
OBJECTIVE:
After completing this lesson each student should be familiar with the requirement for the
installation of Type AC cable.
MATERIALS NEEDED:
Sample of different types of Armored Cable. (If available)
INTRODUCTION:
This Article covers the use and installation requirement for a fabricated assembly of
insulated conductors in a flexible metallic enclosure. Be sure to cover the history of
armored cable, its good and bad qualities as well as the comeback it has made in the
industry.
PRESENTING THE LESSON:
Cover the permitted uses and uses not permitted for Type AC cable and the change in
320.10 item (1) that allows Type AC cable for use as feeders and branch circuits. Note the
requirements for supporting, bending, terminating and installation in accessible attics and
through studs, joists and rafters. It should be pointed out that 320.23 is referred to in other
cable articles as the method of installation in attic spaces.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 34
ARMORED CABLE
ARTICLE 320
Level II
WORKSHEET
1. In general, type AC Cable shall be supported at intervals not exceeding which of the
following?
a. 4 feet
b. 4 ½ feet
c. 5 feet
d. 6 feet
2. Where in accessible attics AC cable is run across the top of floor joists or within what
distance of the floor on the face of a studded rafter the cable shall be protected by
substantial guard strips which are at least as high as the cable.
a. 7 feet
b. 5 feet
c. 3 feet.
d. 2 feet
3. AC cable is not permitted to be used:
a. Wet location
b. Both exposed and concealed work
c. Dry locations
d. In cable trays
2014 NEC Instructors Manual and Student Worksheets – Level 2 35
ARMORED CABLE
ARTICLE 320
Level II
ANSWER KEY
1. 4 1/2 feet 320.30
2. a, 7 feet 320.23(A)
3. a, motion picture studios 320.12
2014 NEC Instructors Manual and Student Worksheets – Level 2 36
FLAT CONDUCTOR CABLE INSTALLATIONS
ARTICLE 324
Level II
OBJECTIVE:
After completing this lesson each student should be familiar with the general requirements
of flat conductor cable (FCC) installations.
MATERIALS:
Samples of the cable and components used to make up complete wiring systems plus
installations instruction will enable students to better understand the requirements and their
importance.
INTRODUCTION:
There are several definitions included in this article which must be reviewed before the
regulations are covered. Applications for this type of system are limited and knowledge of
such limitations is most important.
PRESENTING THE LESSON:
Cover scope, definitions, and limitation of uses found in Part I.
The installation requirements found in Part II should be covered. The showing of
components at the time that the specific requirements are covered will prove beneficial.
The requirements included in Part III are primarily directed to the construction of the
various components of this system. Numerous pieces of equipment will be required,
however, the time spent on these requirements can be minimal.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 37
FLAT CONDUCTOR CABLE INSTALLATIONS
ARTICLE 324
Level II
WORKSHEET
1. FCC systems shall be permitted in all of the following occupancies and locations, except:
a. Damp Locations
b. Office Buildings
c. Store Buildings
d. School Buildings
2. The maximum Voltage to the grounded conductor of FCC systems is:
a. 300
b. 125
c. 277
d. 150
3. What is the maximum size carpet square that can be installed over type FCC cable?
a. 24 inch
b. 39.37 inch
c. 18 inch
d. 48 inch
2014 NEC Instructors Manual and Student Worksheets – Level 2 38
FLAT CONDUCTOR CABLE INSTALLATIONS
ARTICLE 324
Level II
ANSWER KEY
1. d, School Buildings 324.12
2. d, 150 324.10(B)(1)
3. b, 1 meter (39.37 inch) 324.41
2014 NEC Instructors Manual and Student Worksheets – Level 2 39
MINERAL-INSULATED METAL-SHEATHED CABLE
ARTICLE 332
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the requirements for the
installation of MI cable.
MATERIALS NEEDED:
A sample of MI cable. (If available)
INTRODUCTION:
This article covers the requirements for use, installation and construction of Mineral-
Insulated Metal-Sheathed Cable.
PRESENTING THE LESSON:
Cover the definition of MI cable and show an example of MI cable. Note the other articles
that apply to this wiring method. Emphasize where MI cable is permitted and not
permitted to be used.
Part II covers the installation requirement. Cover these requirements: 332.10, 332.12,
332.17, 332.24, 332.30, and 332.40.
Part III gives the construction requirement. Where the outer sheath is made of copper, it
shall provide an adequate path to serve as an equipment grounding conductor. Where the
outer sheath is made of steel, a separate equipment grounding conductor shall be provided.
In as much as listed equipment will be required, the time spent on these requirements can
be minimal.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 40
MINERAL-INSULATED METAL-SHEATHED CABLE
ARTICLE 332
Level II
WORKSHEET
1. Except where fished in, type MI cable shall be supported at intervals not exceeding?
a. 4 1/2 feet
b.6 feet
c. 10 feet
d.5 feet
2. Bends in Type MI shall not be less than which of the following for cable not more than ¾
inches in external diameter.
a. 2
b.5
c. 6
d.10
3. Which of the following shall be used where type MI cable terminates?
a. End Seal Fitting
b. Listed bonding bushings
c. Termination seals
d. Lock nuts
2014 NEC Instructors Manual and Student Worksheets – Level 2 41
MINERAL-INSULATED METAL-SHEATHED CABLE
ARTICLE 332
Level II
ANSWER KEY
1. b, 6 feet 332.30
2. b, 5 332.24
3. a, 332.40
2014 NEC Instructors Manual and Student Worksheets – Level 2 42
FLEXIBLE METALLIC TUBING
ARTICLE 360
Level II
OBJECTIVE:
After completing this lesson each, student should be familiar with the permitted uses,
construction and installation of flexible metallic tubing.
MATERIALS NEEDED:
Sample of flexible metallic tubing. (If available)
INTRODUCTION:
This article applies to a raceway for electrical conductors which are circular in cross
section, flexible, metallic and liquidtight without a nonmetallic jacket.
PRESENTING THE LESSON:
Discuss the permitted uses and uses not permitted for flexible metallic tubing.
The minimum size of flexible metallic tubing shall be metric designator 16 (1/2 inch
electrical trade size). Review the two exceptions to this rule. The maximum size of
flexible metallic tubing shall be metric designator 21 (3/4 inch electrical trade size).
Explain how to determine the number of conductors permitted in 1/2 and 3/4 inch trade size
flexible metallic tubing using Table 1 from Chapter 9.
Also explain procedures for determining the number of conductors in a 3/8 inch flexible
metallic tubing using Table 348.22. Explain Table 348.22.
Discuss how to determine minimum radii by explaining tables 360.24(A) & (B).
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 43
FLEXIBLE METALLIC TUBING
ARTICLE 360
Level II
WORKSHEET
1. Flexible metallic tubing shall be permitted to be used in branch circuits in which of the
following except?
a. In damp locations.
b. Where concealed.
c. In accessible locations.
d. For system voltages of 1,000 volts maximum.
2. A 3/8-inch trade size flexible metallic tubing may be permitted to be installed under which
of the following circumstances?
a. FMT of trade size 3⁄8 shall be permitted in lengths not in excess of 6 ft. as
part of an approved assembly or for luminaires (lighting fixtures).
b. FMT of trade size 3/8 shall be permitted in lengths not in excess of 8 ft. as
part of an approved assembly or for luminaires (lighting fixtures).
c. FMT of trade size 3/8 shall be permitted in lengths not in excess of 4 ft. as
part of an approved assembly or for luminaires (lighting fixtures).
d. FMT of trade size 3/8 shall be permitted in lengths not in excess of 5 ft. as
part of an approved assembly or for luminaires (lighting fixtures).
3. The number of conductors permitted in a 3/4-inch trade size of flexible metallic tubing,
would require you to check which of the following?
a. The percentage of fill specified in Table 1, Chapter 9.
b. The percentage of fill specified in Table 9, Chapter 1
c. The percentage of fill specified in Table 4, Chapter 9
d. The percentage of fill specified in Table 9, Chapter 4
4. The minimum radii for a fixed bend of 1/2-inch flexible metallic tubing should be:
a. 3 1/2 inches
b. 4 inches
c. 5 inches
d. 12 1/2 inches
5. The minimum radii for infrequent flexing use of 3/4 inch flexible metallic tubing should
be:
a. 17 inches
b. 16 7/8 inches
c. 12 1/2 inches
d. 17 1/2 inches
2014 NEC Instructors Manual and Student Worksheets – Level 2 44
FLEXIBLE METALLIC TUBING
ARTICLE 360
Level II
ANSWER KEY
1. a. damp locations 360.10
2. a, 6 feet 360.20(A) exceptions 1 & 2
3. a, Table 1, Chapter 9 360.22
4. b, 4 inches Table 360.24(B)
5. d, 17 1/2 inches Table 360.24(A)
2014 NEC Instructors Manual and Student Worksheets – Level 2 45
ELECTRICAL NONMETALLIC TUBING
ARTICLE 362
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the requirements for the
installation of ENT.
MATERIALS NEEDED:
A sample of ENT and fittings. (If available)
INTRODUCTION:
This article covers the requirements for use, installation and construction of a pliable
corrugated raceway of circular cross-section for the installation of circuit conductors.
PRESENTING THE LESSON:
Cover the definition of ENT and show an example of ENT. Note the other Articles that are
applicable. Special emphasis should be placed on the uses permitted and not permitted.
Note the change in 362.12 that prevents installation any hazardous (classified) location,
except as permitted by other articles in this Code.
Part II covers the installation requirement. Cover minimum and maximum sizes, bending,
supports, etc. (362.10 – 362.60) Note the change for 2008 in Section 362.30 Exception No.
3 that stipulates; For concealed work in finished buildings or prefinished wall panels where
such securing is impracticable, unbroken lengths (without coupling) of ENT shall be
permitted to be fished.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 46
ELECTRICAL NONMETALLIC TUBING
ARTICLE 362
Level II
WORKSHEET
1. The maximum trade size of electrical nonmetallic tubing is which of the following?
a. 1 inches
b. 2 inches
c. 4 inches
d. 6 inches
2. Without exception electrical nonmetallic tubing shall be supported in which of the
following methods?
a. Every 3 feet and within 3 feet of each outlet box.
b. Every 4 feet and within 4 feet of each outlet box.
c. Every 6 feet and within 12 inches of each outlet box.
d. Every 5 feet and within 3 feet of each outlet box.
2014 NEC Instructors Manual and Student Worksheets – Level 2 47
ELECTRICAL NONMETALLIC TUBING
ARTICLE 362
Level II
ANSWER KEY
1. b, 2 inches 362.20(B)
2. 3, 3 362.30(B)
2014 NEC Instructors Manual and Student Worksheets – Level 2 48
BUSWAYS
ARTICLE 368
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the definition and the
structure of a Busway. General requirements in Part I only are covered.
MATERIALS NEEDED:
Drawings, samples of equipment and materials.
INTRODUCTION:
Explain to students that you are going to briefly cover Part I of this article. Busways are
used on almost all industrial and institutional projects.
PRESENTING THE LESSON:
Cover general requirements in Part I and definitions and use in Section. [368.2] Discuss
requirements for support [368.30], branches from busways [368.56], reduction in size of
busway [368.17 B] and overcurrent protection. [368.17 A]
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 49
BUSWAYS
ARTICLE 368
Level II
WORKSHEET
1. Which of the following is/are correct concerning busways?
I. Shall not be installed in hoistways.
II. Busways normally shall be supportive at intervals not exceeding five (5) feet.
a. I only
b. II only
c. Both I and II
d. Neither I nor II
2. Which of the following is/are correct concerning busways?
I. A Dead End of a Busway shall be closed.
II. Busways shall always be installed where they are visible and in the open.
a. I only
b. II only
c. Both I and II
d. Neither I nor II
3. Busways shall be marked with all the following except:
a. Voltage
b. Current
c. Manufacturers name or trademark
d. Frequency
2014 NEC Instructors Manual and Student Worksheets – Level 2 50
BUSWAYS
ARTICLE 368
Level II
ANSWER KEY
1. c, Both I and II 368.12(B), 368.30
2. a, I only 368.10(C) , 368.58
3. d, frequency 368.120
2014 NEC Instructors Manual and Student Worksheets – Level 2 51
CABLEBUS
ARTICLE 370
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the structure and
permitted uses of a Cable Bus and distinguish them from wireways, cable tray.
INTRODUCTION:
Instruct students that you will cover the article briefly, because it is not seen often in field.
It is important to be able to recognize Cable Bus.
PRESENTING THE LESSON:
Use pictures and be certain to cover sections 370.2, 370.3, 370.4, and 370.6
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 52
CABLEBUS
ARTICLE 370
Level II
WORKSHEET
1. The current carrying conductor in cablebus shall have insulation with a minimum rating of
which of the following?
a. 60 degrees C or higher.
b. 75 degrees C or higher.
c. 85 degrees C or higher.
d. 90 degrees C or higher.
2. The minimum size of conductor permitted in cablebus is which of the following?
a. #2
b. #1
c. #1/0
d. #2/0
3. Cablebus shall be normally supported at intervals not exceeding which of the following?
a. 6 feet
b. 8 feet
c. 10 feet
d. 12 feet
2014 NEC Instructors Manual and Student Worksheets – Level 2 53
CABLEBUS
ARTICLE 370
Level II
ANSWER KEY
1. b, 75 degrees C 370.20(A)1
2. c, #1/0 370.20(C)2
3. d, 12 feet 370.30(A)
2014 NEC Instructors Manual and Student Worksheets – Level 2 54
CELLULAR CONCRETE FLOOR RACEWAYS
ARTICLE 372
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with: (1) the type of raceway
covered in Article 372, and not confuse them with Articles 390 or 374. (2) code
requirements for this type of installation.
MATERIALS NEEDED:
NEC, drawings, pictures, handouts.
INTRODUCTION:
Brief overview of Article 372 in code book.
PRESENTING THE LESSON:
Discuss code sections in 372, use drawings and pictures of raceways. Cover definition and
use in 372.2 and 372.4. Emphasize FPN for 372.4. Review installation requirements in
372.5 through 372.13.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 55
CELLULAR CONCRETE FLOOR RACEWAYS
ARTICLE 372
Level II
WORKSHEET
1. Which of the following is/are correct concerning the installation of cellular concrete floor
raceways?
I. Conductors shall not be installed where subject to corrosive vapors.
II. Connections from headers to cabinets shall be made by means of metal
raceways.
a. I only
b. II only
c. Both I and II
d. Neither I nor II
2. Except by special permission, the largest conductor permitted to be installed in cellular
concrete floor raceways is which of the following?
a. #2
b. #1
c. #1/0
d. #2/0
2014 NEC Instructors Manual and Student Worksheets – Level 2 56
CELLULAR CONCRETE FLOOR RACEWAYS
ARTICLE 372
Level II
ANSWER KEY
1. c, Both I and II 372.4(1), 372.6
2. c, #1/0 372.10
2014 NEC Instructors Manual and Student Worksheets – Level 2 57
CELLULAR METAL FLOOR RACEWAYS
ARTICLE 374
Level II
OBJECTIVE:
After completing this lesson each student should:
(1) be familiar with raceways covered in Article 374
(2) be able to distinguish raceways in this article from other articles such as 390 and 372
(3) be familiar with code requirements for this type of installation.
MATERIALS NEEDED:
NEC, drawings, pictures.
INTRODUCTION:
A general, but brief overview of Article 374.
PRESENTING THE LESSON:
Cover definitions and use; Section 374.2 and 374.3, emphasize Informational note of 374.3.
Review installation requirements in Part I. Use handouts, drawings and pictures of
raceways.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 58
CELLULAR METAL FLOOR RACEWAYS
ARTICLE 374
Level II
WORKSHEET
1. Which of the following is/are correct concerning the installation of cellular metal floor
raceways?
I. They shall not be installed where subject to corrosive vapors.
II. They shall not be installed in any hazardous location except as permitted by
other articles in the code.
a. I only
b. II only
c. Both I and II
d. Neither I nor II
2. Except by special permission, the largest conductor permitted in cellular metal floor
raceways is?
a. # 2
b. # 1
c. # 1/0
d. # 2/0
3. In cellular metal floor raceways the combined cross-sectional area of all conductors or
cables shall not exceed what per-cent of the interior cross-sectional area of the cell or
header?
a. 25%
b. 40%
c. 50%
d. 75%
2014 NEC Instructors Manual and Student Worksheets – Level 2 59
CELLULAR METAL FLOOR RACEWAYS
ARTICLE 374
Level II
ANSWER KEY
1. c. both I and II 374.3
2. c, # 1/0 374.4
3. b, 40% 374.5
2014 NEC Instructors Manual and Student Worksheets – Level 2 60
METAL WIREWAYS
ARTICLE 376
AND
NON METALLIC WIREWAYS
ARTICLE 378
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the definition of
wireways, when and where they are used, and be aware of how close they are related to
other raceways such as Busways.
MATERIALS NEEDED:
Pictures, handouts, one type of wireway if available.
INTRODUCTION:
Explain to class that this is a short code section, will be covered briefly, and is important
because it is so commonly used.
PRESENTING THE LESSON:
Cover code sections, use handouts, drawings, and an actual wireway if available. Review
the definitions and use in 376.2 & 10, the size and number of conductors permitted in
wireways. Note the cross-sectional areas and adjustments factors in 376.22 (A) and (B).
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 61
METAL WIREWAYS
ARTICLE 376
AND
NON METALLIC WIREWAYS
ARTICLE 378
Level II
WORKSHEET
1. Metal wireways shall be supported where run horizontally at each end and at intervals not
to exceed which of the following?
a. 5 feet
b. 10 feet
c. 15 feet
d. 20 feet
2. The conductors in a wireway have a cross sectional area of 7.2 square inches. Which of the
following is the minimum size wireway permitted?
a. 4" x 4"
b. 6" x 6"
c. 8" x 8"
d. 12" x 12"
3. Nonmetallic wireways shall be supported where run horizontally at which of the following
intervals unless approved for a greater distance?
a. 5 feet
b. 3 feet
c. 10 feet
d. 4 ½ feet
4. Which of the following statements about nonmetallic wireways is true?
a. An equipment-grounding conductor shall be installed with any extension.
b. Nonmetallic wireway shall be marked with the suffix LS.
c. Both a and b
d. Neither a nor b
2014 NEC Instructors Manual and Student Worksheets – Level 2 62
METAL WIREWAYS
ARTICLE 376
AND
NON METALLIC WIREWAYS
ARTICLE 378
Level II
ANSWER KEY
1. a, 5 feet 376.30(A)
2. b, 6" x 6" 7.2 sq. in. / 20% = 36 sq. in. = 6" x 6" wireway 376.22 &
378.22
3. b, 3 feet 378.30(A)
4. a, an equipment grounding conductor shall be installed 378.70
2014 NEC Instructors Manual and Student Worksheets – Level 2 63
NONMETALLIC EXTENSIONS
ARTICLE 382
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the provisions of
nonmetallic extensions.
MATERIALS NEEDED:
Samples of nonmetallic extensions. (If available)
INTRODUCTION:
Concealable Nonmetallic Extension. A listed assembly of two, three, or four insulated
circuit conductors within a nonmetallic jacket, an extruded thermoplastic covering, or a
sealed nonmetallic covering. Review the areas that this classification includes.
PRESENTING THE LESSON:
Explain how nonmetallic extensions may be permitted for use from an existing outlet,
exposed and in a dry location, and for nonmetallic surface extensions.
Also, review uses not permitted for nonmetallic extensions such as: aerial cable, unfinished
areas and voltage between conductor’s limitations, corrosive vapors and through floors and
partitions.
Extensions shall consist of a continuous unbroken length of the assembly without splices;
however, taps may be made under certain conditions.
The installation of nonmetallic extensions shall be installed as specified in Part II.
The marking of nonmetallic extensions shall comply with Section 110.21.
Note the listing requirements in 382.6 (1-5)
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 64
NONMETALLIC EXTENSIONS
ARTICLE 382
Level II
WORKSHEET
1. Nonmetallic extensions shall be permitted from an existing outlet on which of the
following circuits?
a. A 15 or 20 ampere branch circuit.
b. A 20 or 30 ampere branch circuit.
c. A 30 or 40 ampere branch circuit.
d. A 40 or 50 ampere branch circuit.
2. Nonmetallic extensions of aerial cable may be used where the voltage between conductors
does
not exceed which of the following?
a. 240 Volts
b. 300 Volts
c. 600 Volts
d. 150 Volts
3. Receptacle-type tap conductors shall be of which of the following type?
a. Receptacle-type
b. Removable-type
c. Grounded-type
d. Locking-type
4. With one exception, nonmetallic surface extensions shall be secured in place by approved
means at intervals not exceeding which of the following?
a. 5 inches
b. 6 inches
c. 8 inches
d. 12 inches
2014 NEC Instructors Manual and Student Worksheets – Level 2 65
NONMETALLIC EXTENSIONS
ARTICLE 382
Level II
ANSWER KEY
1. a, 15, 20 382.10(A)
2. b, 300 volts 382.12 #2
3. d, Locking 382.56
4. c, 8 inches 382.30
2014 NEC Instructors Manual and Student Worksheets – Level 2 66
UNDERFLOOR RACEWAYS
ARTICLE 390
Level II
OBJECTIVE:
After completing this lesson, each student should: (1) understand underfloor raceways as
covered in Article 390, and not confuse them with other similar raceways. (2) know the
basic requirements for this type of installation.
MATERIALS NEEDED:
Code book, drawings, pictures of raceways.
INTRODUCTION:
A brief discussion of Article 390 in the code book.
PRESENTING THE LESSON:
Cover the use of underfloor raceways and minimum cover requirements in 390.2(A). Also
cover size of conductors, maximum number of conductors in raceways, splices and taps
and what to do when outlets are discontinued. (390.4 – 390.7)
Review installation requirements as covered in 390.4 through 7.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 67
UNDERFLOOR RACEWAYS
ARTICLE 390
Level II
WORKSHEET
1. In office occupancies, approved metal flat-top raceways not over 4 inches in width shall be
permitted to be laid flush with the concrete floor surface provided they are covered with
substantial floor linoleum with a thickness not less than:
a. 1/16 inch
b. 1/8 inch
c. 1/4 inch
d. 3/8 inch
2. Which of the following is/are correct concerning underfloor raceways?
I. Dead ends of raceways shall be closed.
II. When an outlet is discontinued or removed, the sections of circuit
conductors supplying the outlet(s) shall be removed from the raceway.
a. I only
b. II only
c. Both I and II
d. Neither I nor II
2014 NEC Instructors Manual and Student Worksheets – Level 2 68
UNDERFLOOR RACEWAYS
ARTICLE 390
Level II
ANSWER KEY
1. a, 1/16 inch 390.4(D)
2. c, Both I and II 390.8 & 390.10
2014 NEC Instructors Manual and Student Worksheets – Level 2 69
MESSENGER SUPPORTED WIRING
ARTICLE 396
Level II
OBJECTIVE:
After completing this lesson each student should be familiar with the requirements for
installing messenger supported wiring.
MATERIALS NEEDED:
Example of messenger supported wiring. (If available)
INTRODUCTION:
This Article covers the requirements of a messenger supported wiring system using a
messenger wire to support insulated conductors.
PRESENTING THE LESSON:
Cover the methods of supporting insulated conductor to the messenger wire. Note the other
Articles that apply to this wiring method. Emphasize the permitted uses -- cable type and
location. Note the uses not permitted. Note the requirements for ampacity, support,
grounding and splices and taps.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 70
MESSENGER SUPPORTED WIRING
ARTICLE 396
Level II
WORKSHEET
1. In which of the following locations is messenger supported wiring prohibited?
I. In hoistways.
II. Where subject to physical damage.
a. I only
b. II only
c. Both I and II
d. Neither I or II
2. The conductors of messenger supported wiring shall not be permitted to come into
contact with which of the following?
a. The messenger supports.
b. Structural members.
c. Walls, or pipes.
d. All of the above
2014 NEC Instructors Manual and Student Worksheets – Level 2 71
MESSENGER SUPPORTED WIRING
ARTICLE 396
Level II
ANSWER KEY
1. c, Both I and II hoistways and where subject to physical damage 396.12
2. d, All of the above 396.30
2014 NEC Instructors Manual and Student Worksheets – Level 2 72
OPEN WIRING ON INSULATORS
ARTICLE 398
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with open wiring on
insulators, when and where it may be used, and restrictions that may apply.
MATERIALS NEEDED:
Samples, handouts, materials used in field.
INTRODUCTION:
Explain to students that you will cover this article briefly, touching on the most important
sections that apply to Level II inspectors.
PRESENTING THE LESSON:
This type of installation is not often seen in the field (usually found only in agricultural or
industrial establishments). Cover sections using handouts, samples of materials used in
actual installations. Explain types of wiring and materials used. Use drawings on
chalkboard.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 73
OPEN WIRING ON INSULATORS
ARTICLE 398
Level II
WORKSHEET
1. Which of the following is correct concerning the installations of open wiring on insulators?
I. Shall be permitted on 600 volts, nominal or less for industrial or agricultural
establishment
II. Restricted to dry locations only.
a. I only
b. II only
c. Both I and II
d. Neither I nor II
2. Conductor must be supported within how many inches of a tap or splice?
a. 6 inches
b. 10 inches
c. 12 inches
d. 54 inches
3. When nails are used to mount knobs for open wiring, the nails must be a minimum size of?
a. 8 penny
b. 10 penny
c. 12 penny
d. 16 penny
4. Open wiring in accessible attics with stairways must be protected from physical damage if
it is not installed at least a minimum height of?
a. 2 feet
b. 4 feet
c. 6 feet
d. 7 feet
5. Open conductors shall be separated from metal raceways, piping, or other conducting
material a minimum distance of?
a. 2 inches
b. 4 inches
c. 6 inches
d. 12 inches
2014 NEC Instructors Manual and Student Worksheets – Level 2 74
OPEN WIRING ON INSULATORS
ARTICLE 398
Level II
ANSWER KEY
1. a, I only 398.10
2. a, 6 inches 398.30(A)
3. b, 10 penny 398.30(D)
4. d, 7 feet 398.23(A)
5. a, 2 inches 398.19
2014 NEC Instructors Manual and Student Worksheets – Level 2 75
FIXED ELECTRIC SPACE HEATING EQUIPMENT
ARTICLE 424
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the basic code
requirements for fixed electric space heating.
INTRODUCTION:
This article includes requirements for several different types of heating systems some of
which will only be encountered infrequently such as heating cable, unit heaters, boilers,
central systems, etc. It does not apply to process heating or room air conditioners.
PRESENTING THE LESSON:
NOTE: This lesson is a review of Level 1, Article 424.
Branch Circuit Requirements
Branch circuits supplying more than one outlet for fixed electric heaters (baseboard
heaters) shall be rated 15, 20, 25 or 30 amperes. Fixed infrared equipment located in other
than residential occupancies can be supplied from branch circuits rated not over 50
amperes. [424.3(A)] Branch circuits supplying only one piece of equipment must be rated
125% of the total load including motors and resistance heaters, except for relays and
contactors which are approved for continuous operation at 100% ampacity [424.3(B)].
Heat pump compressors are covered under Article 440.34 and 35.
Installation
If heating equipment requires more than 60 degrees Celsius insulation on supply wiring, it
must be clearly marked and the marking must be visible after installation. (424.11)
Locations
Units subject to physical damage shall be protected in an approved manner. Climate in wet
or damp areas shall be approved for such location and installed so liquid cannot enter.
(424.12)
Spacing from Combustible Material
Equipment shall be installed to provide manufacture’s requirements for clearance to
combustible materials. 424.13
Control and Protection
A disconnecting means must be provided to disconnect all ungrounded conductors where
supplied from more than one source, disconnects shall be grouped. (424.19)
2014 NEC Instructors Manual and Student Worksheets – Level 2 76
A disconnecting means for units equipped with supplementary overcurrent devices shall be
within sight from and on the supply side of supplementary overcurrent protection, and
comply with numbers 1 or 2 below.
1. For motors not over 1/8 horsepower, a disconnecting means shall be permitted to serve
both the motor controller and heater if located within sight of both or the disconnecting
means must be capable of being locked in the open position. Where unit switches meet
the requirements of 424.19(C) they may be used as the required disconnecting means.
2. Units containing motors rated over 1/8 horsepower, disconnect described in number 1
above may be used, if within sight of the motor controller and heater.
Please emphasize this: Disconnecting means not within sight from the heater requires either
a separate disconnect be installed or a disconnect capable of being locked open or unit
switches complying with 424.19(C)
A branch circuit switch or circuit breaker may serve as a disconnecting means for units
containing motors not more than 1/8 horsepower where readily accessible for servicing.
Units more than 1/8 horsepower will require a disconnect within sight of motor controller.
Unit switches may be used as disconnecting means where provided with a marked "off"
position and when meeting requirements of 424.19(C) for the type of occupancy involved.
Thermostatically controlled switching devices may be used as both a controller and a
disconnecting means under ALL the following conditions.
Example: thermostats for basement heat
1. Marked "off" position
2. Must open all ungrounded conductors when in "off" position (manually)
3. Must not be capable of being automatically energized when in the manual "off"
position.
4. Must be located as per Section 424.19.
Switches must be of the type indicating the "on" and "off" positions. 419.20
Overcurrent Protection
Space heating equipment supplied by branch circuits in Article 210 shall be permitted
where not supplying motor operated equipment as in Article 430.440. [424.22(A)]
Resistance-type heating elements may not be protected at more than 60 amperes. Where
rated more than 48 amperes, it shall be subdivided not to exceed 48 amperes within each
subdivided load. [424.22(B)]
Overcurrent protective devices for subdivided loads shall be factory installed or factory
provided, accessible and suitable for branch circuit protection. (see Article 240.10).
2014 NEC Instructors Manual and Student Worksheets – Level 2 77
Conductors supplying supplementary overcurrent protective devices shall be considered
branch circuit conductors. [see 424.22(D].
Field installed conductors between supplementary protective devices and heater shall be
sized not less than 125% of load. Overcurrent protective devices shall comply with Article
240.3. [424.22(E)].
Marking of Heating Equipment
Each unit must have manufacturer's nameplate installed and visible after installation.
[424.28(A & B)]
Space Heating Cables
Area heating cables shall not extend beyond the room in which they originate. They shall
not be installed in closets, over walls or over cabinets. [424.38]
Heating cables must be at least 8 inches from the edge of outlet boxes and junction boxes,
and at least 2 inches from recessed fixtures. [424.39]
Adjacent runs of cable not less than 1 1/2 inch on center and secured at intervals not
exceeding 16 inches. [424.41(B)(F)]
Splices in the cable should be made only where necessary and in no case to alter length of
cable. Cables shall cross joists only at ends of room. [424.41(D)(J)]
Heating cables shall not exceed 16 1/2 watts per linear foot in concrete or masonry floors.
[424.44(A)]
All cable installations must be inspected before being covered. Review typical installation
procedures. [424.45]
Duct Heaters
All duct heaters must first be identified as suitable for installation. [424.58]
If duct heater is located within 4 feet of a heat pump or air conditioner it must be identified
as suitable for such installation. [424.61]
The fan circuit must be interlocked to insure fan is running when heater is on. [424.63]
Each heater must be provided with limit devices. [424.64]
A disconnecting means must be at or within sight from the controller. [424.65]
Installation must meet manufacturer's instructions. [424.66]
2014 NEC Instructors Manual and Student Worksheets – Level 2 78
Electrode-type Boilers
Branch circuit conductors and protective devices shall be calculated at 125% of total load
except for contactors, relay, or other devices approved for continuous operation at 100% of
rating. [424.82]
Over temperature and over pressure limiting controls are required and must meet the same
requirements as for resistance-type boilers. [424.83]
All boilers must be marked with manufacturer's name, rating and electrical supply required.
In addition, a warning: "ALL POWER SUPPLIES SHALL BE DISCONNECTED
BEFORE SERVICING INCLUDING SERVICING THE PRESSURE VESSEL." must
appear. [424.86]
Electric Radiant Heating Panels and Heating Panel Sets
This section of Article 424 applies to wall heaters, baseboard heaters and other heating
units, which may be exposed or concealed when installation is complete. Heating panels
and heating panel sets must be installed to meet manufacturer's installation instructions,
and the conditions of Section 424.93(A)(1) & (2):
1. Must not be installed subject to physical damage
2. Must not run through or above walls, partitions, or other structures that extend to
ceilings.
3. Must not run through or in thermal insulation.
Excess non-heating leads of heating panels and heating panel sets may be cut to desired
length. [424.97]
Heating panels or panel sets installed in concrete or poured masonry must meet the
requirements of Section 424.98. (Review requirement).
Heating panels installed under floor covering must be installed in accordance with
instructions and identified for such use and provided with fault protection in accordance
with Section 424.99. It is important for the inspector to have access to installation
instructions for the specific panel installed. Inspection must be made prior to applying
floor covering. Heating panels installed under floor covering shall not exceed 15 watts per
square foot. [424.99]
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 79
FIXED ELECTRIC SPACE HEATING EQUIPMENT
ARTICLE 424
Level II
WORKSHEET
1. Branch circuits supplying two or more outlets for fixed electric heat in a dwelling shall not
be rated more than which of the following?
a. 15 amperes.
b. 20 amperes.
c. 25 amperes.
d. 30 amperes.
2. Ampacity of branch circuit conductors supplying fixed electric space heating equipment
with resistance elements shall not be less than what percentage of the total load of the
heaters and motors.
a. 150 percent
b. 125 percent
c. 100 percent
d. 80 percent
3. The disconnecting means for electric heat units shall be in sight and a maximum distance
from the unit of?
a. 10 feet
b. 12 feet
c. 25 feet
d. 50 feet
4. For fixed electric space-heating equipment without a motor rated over 1⁄8 hp, the branch-
circuit switch or circuit breaker shall be permitted to serve as the disconnecting means
where the switch or circuit breaker in which of the following conditions?
I. Is within sight from the heater
II. Is capable of being locked in the open position.
a. I only
b. II only
c. Neither I or II
d. Both I and II
2014 NEC Instructors Manual and Student Worksheets – Level 2 80
5. Which of the four things listed are necessary for a thermostatically controlled switching
device to be used as both the controller and disconnecting means?
a. Marked "off" position.
b. Directly open all ungrounded conductors when manually placed in "on" position.
c. Can be energized automatically when in "off " position.
d. Located as specified in 430.19.
6. Heating equipment requiring supply conductors to be rated over which of the following
temperatures shall be clearly marked?
a. 60 degrees C
b. 75 degrees C
c. 90 degrees C
d. 40 degrees C
7. Resistance-type heating elements in electric space heating equipment shall be protected at
not more than which of the following in amperes?
a. 40 amperes
b. 50 amperes
c. 60 amperes
d. 125 amperes
8. The conductors supplying the supplementary overcurrent protective devices shall be
considered which of the following?
a. Feeders
b. Branch circuit conductors
c. Service conductors
d. Lateral circuit conductors
9. What would be the minimum THW wire size and fuse size for a 5 KW resistance heater
with a 3 ampere fan motor rated 240 volt, 1 Ø?
a. # 8 and 40 amperes
b. # 10 and 30 amperes
c. # 6 and 50 amperes
d. # 12 and 25 amperes
2014 NEC Instructors Manual and Student Worksheets – Level 2 81
10. Electric space heating cables in ceilings shall be located a minimum distance of how far
from recessed light fixtures?
a. 2 inches
b. 8 inches
c. 12 inches
d. 16 inches
11. Heating cables shall be furnished complete with factory-assembled non-heating leads at
which of the following lengths?
a. At least 4 ft. in length.
b. At least 5 feet in length
c. At least 6 feet in length.
d. At least 7 feet in length.
12. When installing heating cables in ceilings, which of the following is the minimum amount
of
non-heating leads permitted to be left in a junction box?
a. 2 inches
b. 4 inches
c. 6 inches
d. 8 inches
13. Heat pumps and air conditioners having duct heaters closer than which of the following
distance to the heat pump or air conditioner shall have both the duct heater and heat pump or
air conditioner identified as suitable for such installation and so marked?
a. 2 feet
b. 4 feet
c. 3 feet
d. 6 feet
14. Duct heater controller equipment shall be either accessible with the disconnecting means
installed at or within sight from the controller in accordance with which of the following
Code sections?
a. 430.250 (A)
b. 430.248 (A)
c. 424.20 (A)
d. 424.19 (A)
2014 NEC Instructors Manual and Student Worksheets – Level 2 82
15. A boiler employing resistance-type heating elements not contained in an ASME rated and
stamped vessel shall have the heating elements protected at not more than which of the
following?
a. 48 amperes
b. 60 amperes
c. 70 amperes
d. 100 amperes
16. A 25 KW, 480 volt, 3 phase electric heat unit is to be installed using THW copper; which
of the following is the minimum size conductor permitted for the branch circuit conductor
for this unit? Note: All conductors are considered to be copper and operating at 60 degrees
unless otherwise stated.
a. #10
b. #8
c. #6
d. #4
17. An ASME rated boiler shall have its loads subdivided if the load on an element exceeds:
a. 24 amperes
b. 120 amperes
c. 48 amperes
d. 60 amperes
18. List the marking not required on electrode type boilers.
a) Manufacturer’s address.
b) Rating in volts, amperes, and KW.
c) Supply frequency, number of phases, and number of wires.
d) Marked "Electrode - type boiler"
e) Marked " ALL POWER SUPPLIES SHALL BE DISCONNECTED
BEFORE SERVICING INCLUDING SERVICING THE PRESSURE
VESSEL."
19. A complete assembly provided with a junction box or length of flexible conduit for
connection to a branch circuit is which of the following?
a. A radiator panel.
b. A radiant heating panel.
c. A heating panel set.
d. A heating boiler set.
2014 NEC Instructors Manual and Student Worksheets – Level 2 83
20. Heating panels or panel sets installed under floor covering shall not exceed which of the
following in watts per square foot of heated area?
a. 25 watts
b. 20 watts
c. 16 watts
d. 15 watts
2014 NEC Instructors Manual and Student Worksheets – Level 2 84
FIXED ELECTRIC SPACE HEATING EQUIPMENT
ARTICLE 424
Level II
ANSWER KEY
1. d, 30 amperes 424.3(A)
2. b, 125% 424.3(B)
3. d, 50 feet 424.19(A)
4. d, Both I and II 424.19(B)(1)
5. a, Marked "off" position. 424.20(A)
6. a, 60 degrees C 424.11
7. c, 60 424.22(B)
8. b, Branch circuit conductors 424.22(D)
9. b, Use # 10 THW copper wire and a 30 ampere fuse.
(5 KW 5000/240 = 20.8 + 3 = 23.8 times 125% = 29.7) 424.3(B)
10. a, 2 inches 424.39
11. d, at least 7 feet in length 424.34
12. c, 6 inches 424.43(B)
13. b, feet 424.61
14. d, 424.19 424.65
15. a, 48 amperes 424.72(B)
16. b, #8, 25,000 ÷480 ÷ 1.732 = 30.0 amperes x 125% = 37.58 amperes 310.16
Look in 310.16 at THW copper = # 8 wire
17. b 120 amps 424.72(A)
18. a, Manufacturer’s name is required 424.86
19. b, A radiant heating panel 424.91
20. d, 15 Watts 424.99(B)
2014 NEC Instructors Manual and Student Worksheets – Level 2 85
FIXED OUTDOOR ELECTRIC DE-ICING AND SNOW-MELTING EQUIPMENT
ARTICLE 426
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the requirements for
Fixed Outdoor Electric De-Icing and Snow-Melting Equipment.
MATERIALS NEEDED:
Pictures of different types of units including their installations.
INTRODUCTION:
The requirements of this article apply to electrically energized heating systems and the
installation of these systems.
PRESENTING THE LESSON:
Article 426 covers snow-melting and de-icing equipment embedded in driveways, walks,
steps and other areas. Exposed systems are used for drainage systems, bridges, roofs and
other structures. Emphasis should be placed on definitions in 426.2 relating to this article.
Note other applicable articles covered in 426.3. Branch circuit and overcurrent sizing is
covered in 426.4, note the 125% requirement for the branch circuit conductors.
Part II covers the installation requirements. Special attention should be given to 426.10 (2)
emphasizing that these systems shall be installed according to the manufactures drawings
and instructions. Also note 426.14 for special permission requirements.
Part III covers resistance heating elements requirements. Emphasis should be placed on
spacing in 426.20(B) cover 426.20(C) secured in (D) and expansion and contractions in
(E).
Installation requirements for the non-heating leads for embedded equipment should be
covered emphasizing the raceways, grounding and lead in junction boxes.
Part IV covers impedance heating. Explain impedance heating and also skin effect heating.
In Part V go over disconnection and overcurrent protection. In 426.51 controllers, explain
the different types of controllers and their functions.
2014 NEC Instructors Manual and Student Worksheets – Level 2 86
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 87
FIXED OUTDOOR ELECTRIC DE-ICING
AND SNOW-MELTING EQUIPMENT
ARTICLE 426
Level II
WORKSHEET
1. The ampacity of branch-circuit conductors for snow-melting equipment shall not be less
than what percent of the total load of the heaters?
a. 80 %
b. 100 %
c. 125 %
d. 250 %
2. Resistance heating units of snow-melting equipment shall not exceed which of the
following in watts per square foot of heated area?
a. 100 watts psf
b. 120 watts psf
c. 350 watts psf
d. 500 watts psf
3. Each factory-assembled fixed outdoor de-icing heating unit shall be:
A) Legibly marked within 3 inches of each end of the non-heating leads
B) Marked with the permanent identification symbol, catalog number, and rating in
volts and amperes.
a. A only
b. B only
c. both A and B
d. neither A nor B
4. The factory installed cord and plug, as well as plug connected equipment rated which of the
following shall be permitted to be the disconnecting means.
a. 20 amperes or less and 150 volts or less to ground
b. 30 amperes or less and 150 volts or less to ground
c. 40 amperes or less and 150 volts or less to ground
d. 50 amperes or less and 150 volts or less to ground
2014 NEC Instructors Manual and Student Worksheets – Level 2 88
5. Fixed outdoor de-icing equipment shall be protected by one of the following methods:
a. motor rated switch
b. circuit breaker
c. fuses
d. ground fault branch circuit protection
2014 NEC Instructors Manual and Student Worksheets – Level 2 89
FIXED OUTDOOR ELECTRIC DE-ICING
AND SNOW-MELTING EQUIPMENT
ARTICLE 426
Level II
ANSWER KEY
1. c, 125 426.4
2. b, 120 426.20
3. c, both A and B 426.25
4. a, 20, 150
426.50(B)
5. d, ground fault branch circuit protection 426.28
2014 NEC Instructors Manual and Student Worksheets – Level 2 90
MOTORS, MOTOR CIRCUITS, AND CONTROLLERS
ARTICLE 430
Level II
OBJECTIVE:
After completing this lesson, each student should have an understanding of the sections in
Article 430 that pertain to level II inspectors.
INTRODUCTION:
Much of Article 430 has been covered in Level I. The intent here is to review the
information and place additional emphasis on the following:
PRESENTING THE LESSON:
As with any installation; safety depends on proper application of equipment. Equipment
installed in location where dust or flying material are present and will collect on or in
motors in such quantities to seriously interfere with ventilation and cooling, dangerous
temperatures will result. Suitable types of enclosed motors shall be used. (Section 430.16)
As a general rule, motor applications are considered to be for continuous duty unless the
nature of the apparatus it drives is such that the motor cannot operate continuously with
load under any conditions of use. See the Duty-Cycles Service, show Table 430.22(E) for
Exceptions involving Short-Time Duty, Intermittent Duty, Periodic Duty, and Varying
Duty applications. Review the requirements of several motors on one branch circuit found
in Section 430.53(A).
Cover in detail the requirements found in Section 430.53(C) for other Group installations.
Give example and have controllers to show how to determine maximum rating of fuse and
for circuit breakers.
Section 430.72 (A) and (B) was covered in Level I. Sub-Section (C) needs to be added so
that control circuit transformers are provided with the necessary overcurrent protection.
APPLICATION:
If time will allow, let the class time answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 91
MOTORS, CIRCUITS, AND CONTROLLERS
ARTICLE 430
Level II
WORKSHEET
1. For a portable motor, the controller shall be permitted to be an attachment plug and
receptacle if the motor is rated at not over which of the following?
a. 1/8 Hp
b. 1/3 Hp
c. 3/4 Hp
d. 1 Hp
2. A motor is to be connected to a feeder tap not over 25 feet in length. Which of the
following is correct?
I. Tap conductor must have an ampacity at least one-third that of the feeder
conductor.
II. Be protected from physical damage.
a. I only
b. II only
c. both I and II
d. neither I nor II
3. A 480 volt, 40 Hp, 3 phase, Code Letter "B" synchronous type motor is to be protected by
dual element fuses. Which of the following is the maximum size fuse permitted to protect
the branch circuit conductor for the motor? (Motor has a power factor of .90). (Do not use
Exception).
a. 50 ampere
b. 60 ampere
c. 100 ampere
d. 80 ampere
4. Which of the following is the minimum ampacity permitted to size the branch circuit
conductor for a 40 Hp, 480 volt, 3 phase, synchronous type motor with a power factor of
.90?
a. 45 amperes
b. 72 amperes
c. 50 amperes
d. 70 amperes
2014 NEC Instructors Manual and Student Worksheets – Level 2 92
5. Three motors are supplied by the same feeder, one with a full load ampacity of 28 amps
protected by a 45 amp dual element fuse, the other two with a full load ampacity of 22
amperes each, protected by 30 ampere dual element fuse each. Which of the following is
the maximum size fuse permitted to protect the feeder?
a. 70 amperes
b. 80 amperes
c. 90 amperes
d. 100 amperes
6. Which of the following is the minimum ampacity permitted to size the branch circuit
conductor for a 10 Hp, 208 volt, single phase, squirrel cage, induction type motor?
a. 39
b. 55
c. 60
d. 69
7. An intermittent duty motor, serving a freight elevator, is a 30 minute rated motor. Which
of the following is the minimum percent to be used when calculating the branch circuit
conductor for this motor?
a. 80%
b. 90%
c. 115%
d. 125%
8. When installing branch circuit conductors and a controller, which of the following is
correct? (Motor is a continuous duty motor)
I. Thermal overload heater must be installed in all ungrounded conductors.
II. Branch circuit conductor must be calculated at 125% of the full load current of
the motor.
a. I only
b. II only
c. both I and II
d. neither I nor II
9. The branch circuit conductors for a motor are protected by time-delay (dual element) fuses.
If the fuses are not holding on the line, they may be increased to a maximum of:
a. 150%
b. 175%
c. 200%
d. 225%
2014 NEC Instructors Manual and Student Worksheets – Level 2 93
10. A feeder is to supply two motors, with a full load ampacity of 28 amperes each and a non-
continuous lighting load of 100 amps. Which of the following is the minimum size
conductor permitted for this feeder, using THHN copper?
a. #3
b. #2
c. #1
d. #1/0
"NOTE" ALL MOTORS IN THESE QUESTIONS (11-16) ARE AC TYPE MOTORS.
11. What is the minimum size THW conductor permitted to serve as the branch circuit
conductors for a 10 Hp, 240 volt, 3 phase, squirrel cage, induction type motor?
a. #12
b. #10
c. #8
d. #6
12. Which of the following is the minimum ampacity permitted to size the branch circuit
conductors for a 30 Hp, 480 volt, 3 phase, synchronous type motor?
a. 32 amperes
b. 40 amperes
c. 44 amperes
d. 63 amperes
13. A general use, non-fusible type disconnect shall be rated at what percent of the full load
current of the motor?
a. 80%
b. 100%
c. 115%
d. 125%
14. Which of the following is the normal size motor overload permitted for a 20 Hp, 240 volt, 3
phase, squirrel cage, induction type motor with a service factor of 1.15 and a nameplate
current rating of 52 amperes? (The motor overload shall be based on the nameplate current
rating).
a. 62.10
b. 67.50
c. 70.20
d. 75.60
2014 NEC Instructors Manual and Student Worksheets – Level 2 94
15. A feeder is to serve three motors; one with a full load ampacity of 42 amperes, two with a
full load ampacity of 28 amperes each. Using THW copper, which of the following is the
minimum size feeders permitted for these three motors?
a. #4
b. #3
c. #2
d. #1
16. Which of the following is the maximum size dual element fuses permitted to protect the
branch circuit conductors for a 5 Hp, 240 volt, single phase, squirrel cage, induction type
motor? (Do not use any exceptions)
a. 40 amperes
b. 45 amperes
c. 50 amperes
d. 60 amperes
2014 NEC Instructors Manual and Student Worksheets – Level 2 95
MOTORS, CIRCUITS, AND CONTROLLERS
ARTICLE 430
Level II
ANSWER KEY
1. b, 1/3 Hp 430.81(B)
2. c, both I and II 430.28(2)
3. c, 70 amp 40 Hp. 52 amperes x 1.1 = 57.2 amperes x 175% = 100 = 100 ampere
fuse
Table 430.250, 430.52,
Table 430.52
4. b, 56 amps; 40 Hp. 52 amperes x 1.1 = 57.2 amperes x 125% = 71.5 = 70 amperes
Table 430.250, 430.22(A),
Table 310.15(B)(16), 240.6
5. b, 80 amperes, 45 + 22 + 22 = 89 amperes = 80 amperes 430.62
6. d, 69; 55 x 125% = 68.75 = 69 430.22(A),
Table 430.148
7. b, 90% 430.22(E),
Table 430.22(E)
8. c, both I and II 430.22(A), 430.32(A)(1),
Table 310.15(B)(16)
9. d, 225% 430.52(C) Exception 2(b)
10. d, #1/0 , (28 x 125%) + 28 + 100 = 163 amperes 430.24
11. b, #10, 430.22(A), Table 430.150,
Table 310.15(B)(16)
28 amperes x 125% = 35 amperes = #10 THW
12. b, 40 amperes, 32 amperes x 25% = 40 amperes 430.22(A),
Table 430.150
13. c, 115% 430.110(A)
14. b, 67. 50 , 54 amperes x 125% = 67.50 430.6(A)(2), 430.32(A)(1)
15. c, #2; (42 x 125%) + 28 + 28 = 108.5 amperes = #2 430.24, Table 310.15(B)(16)
16. b, 45 amperes ; 28 amperes x 175% = 49 amperes = 45 amperes
430.6, 430.52,
Table 430.52
2014 NEC Instructors Manual and Student Worksheets – Level 2 96
TRANSFORMERS AND TRANSFORMER VAULTS
ARTICLE 450
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the code requirements
for installations of transformers, covering the location normally used, different types and
purposes.
MATERIALS NEEDED:
Pictures or transparencies of different types of transformers.
INTRODUCTION:
With few exceptions, this article applies to all transformers. (See 450-1 for exceptions)
Transformers are most likely encountered in large commercial and industrial installations.
PRESENTING THE LESSON:
Article 450 covers individual transformers, single or polyphase, identified by a single
nameplate. This article also covers the installation of transformers in hazardous locations,
except as modified by Articles 501-503.
Part II covers specific provisions applicable to different types of transformers. Although the
dry transformer is the most common seen in the field, special attention is given to the oil
filled transformer, because of the danger involved.
Part III covers transformer vaults; their installations and safe guards against fire.
Discuss the different types of transformers, voltages, and KVA.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 97
TRANSFORMERS AND TRANSFORMER VAULTS
ARTICLE 450
Level II
WORKSHEET
1. When grounding separately derived AC systems, all of the following are approved
grounding electrodes EXCEPT:
(a) The nearest available effectively grounded structural metal member of the
structure.
(b) The nearest available effectively grounded metal water pipe.
(c) A driven electrode, eight feet in length.
(d) The metallic raceway enclosing the conductors to the system.
2. In general, each transformer of 1000 volts or less is required to have individual primary
overcurrent protection. This overcurrent device is to be rated or set at not over which of
the following percentage of the primary current?
a. 125%
b. 150%
c. 200%
d. 300%
3. Which of the following is the maximum KVA dry-type transformer permitted to be
installed indoors with 12 inch separation from combustible material?
a. 35
b. 75
c. 112 ½
d. 125
4. A 50 KVA dry-type transformer is to be installed inside of an industrial building. In
general, which of the following is the minimum required distance of separation the
transformer must be from combustible material? .
a. 6 inches
b. 12 inches
c. 24 inches
d. 6 feet
5. What is the largest KVA dry type transformer that may be installed in the hollow spaces of
fire resistant ceiling?
a. 75 KVA
b. 112 1/2 KVA
c. 25 KVA
d. 50 KVA
2014 NEC Instructors Manual and Student Worksheets – Level 2 98
TRANSFORMERS AND TRANSFORMER VAULTS
ARTICLE 450
Level II
ANSWER KEY
1. d, The metallic raceway enclosing the conductors to the system 250.30(A)(4)
2. a, 125% T-450.3(B)
3. c, 112 1/2 450.21(A
4. b, 12 inches 450.21(A)
5. d, 50 KVA 450.13(B)
2014 NEC Instructors Manual and Student Worksheets – Level 2 99
CAPACITORS
ARTICLE 460
Level II
OBJECTIVE:
After completing this lesson, each student should familiar with types of capacitors, where
they are normally used, and basic code requirements applicable to them.
INTRODUCTION:
Explain to student that this article is brief. Only a few minutes should be spent on this
article.
PRESENTING THE LESSON:
Cover code section briefly. Have capacitor available to show students and/or wiring
diagram of a capacitor. Cover Section 460.10, Grounding. Note that capacitor cases shall
be connected to the equipment grounding conductor.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 100
CAPACITORS
ARTICLE 460
Level II
WORKSHEET
1. The residual voltage of a capacitor at or below 1000 volts shall be reduced to 50 volts,
nominal or less within how many minutes after the capacitor is disconnected from the
source of supply?
a. 1 minute
b. 2 minutes
c. 4 minutes
d. 5 minutes
2. The ampacity of capacitor circuit conductor at 1000 volts or less shall not be less than what
percent of the rated current of the capacitor?
a. 80%
b. 100%
c. 125%
d. 135%
3. Each capacitor of less than 1000 volts shall be provided with a nameplate giving all the
following except which of the following?
a. rated voltage
b. frequency
c. number of phases
d. maximum overcurrent device for capacitor
2014 NEC Instructors Manual and Student Worksheets – Level 2 101
CAPACITORS
ARTICLE 460
Level II
ANSWER KEY
1. a, 1 minute 460.6(A)
2. d, 135% 460.8(A)
3. d, maximum overcurrent device for capacitor 460.12
2014 NEC Instructors Manual and Student Worksheets – Level 2 102
STORAGE BATTERIES
ARTICLE 480
Level II
OBJECTIVE:
After completing this lesson each student should be: (1) acquainted with the NEC
requirements for storage batteries; (2) familiar with different types of batteries, such as
lead acid or alkaline type batteries.
INTRODUCTION:
A brief discussion of Article 480 in the code book.
PRESENTING THE LESSON:
Discuss code sections, different types of batteries, use handouts.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 103
STORAGE BATTERIES
ARTICLE 480
Level II
WORKSHEET
1. Insulation shall be provided between groups of cells and shall have a minimum separation
between live battery parts of opposite polarity of:
a. 1 inch
b. 2 inches
c. 4 inches
d. 6 inches
2. Which of the following is correct concerning the location of racks for storing batteries?
I. Racks for storage of batteries may be made of fiberglass materials.
II. Provision shall be made for sufficient diffusion and ventilation of battery gases.
a. I only
b. II only
c. Both I and II
d. Neither I nor II
2014 NEC Instructors Manual and Student Worksheets – Level 2 104
STORAGE BATTERIES
ARTICLE 480
Level II
ANSWER KEY
1. b, 2 inches 480.7
2. c, Both I and II 480.8(A)(2) & 480.9(A)
2014 NEC Instructors Manual and Student Worksheets – Level 2 105
HAZARDOUS (CLASSIFIED) LOCATIONS - SPECIFIC
ARTICLE 510
Level II
OBJECTIVE:
After completing this lesson, each student should have a basic understanding of the code
requirements concerning hazardous locations.
INTRODUCTION:
Atmospheric concentrations of flammable liquids, gases, vapors or deposits of materials
which may readily ignite pose a hazard to occupancies that are covered in Articles 511
through 517.
PRESENTING THE LESSON:
Explain to the students that the rules of this article shall apply to wiring and equipment in
occupancies covered in Articles 511 through 517.
Article 514 covering gasoline dispensing and service stations has been covered in the level
I course and will not be covered in this course.
Also, note that in the event of unusual conditions in an occupancy, the authority having
jurisdiction shall judge with respect to the application of specific rules.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 106
HAZARDOUS (CLASSIFIED) LOCATIONS - SPECIFIC
ARTICLE 510
Level II
WORKSHEET
1. What articles cover occupancies or parts of occupancies that are or may be hazardous
because of atmospheric concentration of flammable liquids, gases, and vapors?
2014 NEC Instructors Manual and Student Worksheets – Level 2 107
HAZARDOUS (CLASSIFIED) LOCATIONS - SPECIFIC
ARTICLE 510
Level II
ANSWER KEY
1. 510.1 Articles 511 through 517
2014 NEC Instructors Manual and Student Worksheets – Level 2 108
COMMERCIAL GARAGES
ARTICLE 511
Level II
OBJECTIVE:
Each student should become familiar with the definition as well as the wiring methods and
materials for use in a commercial garage.
MATERIALS NEEDED:
Show samples of Raceways, Seal-off fitting, explosion proof equipment.
INTRODUCTION:
Let students know this is a very serious matter in the field and that you will cover this
section in detail (read Article 510 and review). Other codes sections are closely related,
such as 500, 501, 502.
PRESENTING THE LESSON:
Discuss Articles 511, 501, 502, cover 511 in detail. Use handouts to illustrate certain areas
in garages, to insure students know or can identify certain areas of classification in garages.
Be sure students are familiar with wiring methods and materials for this installation. The
article is a very popular installation in the field.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 109
COMMERCIAL GARAGES
ARTICLE 511
Level II
WORKSHEET
1. In a commercial garage each floor area, without ventilation, up to a level of 18 inches
above the floor shall be considered to be which of the following locations?
a. Class I, Div. I
b. (b)Class I, Div. 2
c. Class II, Div. I
d. Class II, Div. 2
2. All of the following methods or materials are approved for wiring above the Class I
location in garages except which of the following?
a. rigid non-metallic conduit
b. electrical non-metallic tubing
c. non-metallic sheathed cable
d. MI type cable
3. Lamps and lampholders for fixed lighting that are installed over vehicle service lanes shall
be located no less than what distance above the floor, unless the lamp is of the totally
enclosed type?
a. 8 feet
b. 10 feet
c. 12 feet
d. 14 feet
4. When wiring commercial garages, which of the following is correct?
I. All 125 volt, 15 and 20 amp receptacles for electrical hand tools and portable
lighting devices shall have ground-fault protection for personnel.
II. All 240 volt receptacles in garage shall have ground-fault protection for
personnel.
a. I only
b. II only
c. Both I and II
d. Neither I nor II
2014 NEC Instructors Manual and Student Worksheets – Level 2 110
COMMERCIAL GARAGES
ARTICLE 511
Level II
ANSWER KEY
1. b, Class I, Div. 2 511.3(B)(3)(1)
2. c, non-metallic sheathed cable 511.7(A)(1)
3. c, 12 feet 511.7(B)(1)(b)
4. a, I only 511.12
2014 NEC Instructors Manual and Student Worksheets – Level 2 111
THEATERS AND SIMILAR LOCATIONS
ARTICLE 520
Level II
OBJECTIVE:
After completing this lesson, each student should have a basic understanding of the
requirements of Article 520 as related to Theaters and Similar Locations.
MATERIALS NEEDED:
Slides or pictures of theater switchboards and equipment.
INTRODUCTION:
This article covers the requirements for Theaters and Similar Locations. Equipment such
as Fixed Stage Switchboards and stage equipment, Portable Stage Switchboards and stage
equipment and dressing rooms are included.
PRESENTING THE LESSON:
This article covers the wiring methods and equipment in buildings used for dramatic,
musical motion picture, projection and television studios, which have assembly areas.
Part I covers general wiring requirements. Motion Picture Projectors, Emergency systems
and Sound Reproduction are covered in their applicable articles (540, 640, 700). Emphasis
should be placed on wiring methods and note should be made of the waiver of the 30
conductor limitation for auxiliary gutters and wireways.
Part II covers Fixed Stage Switchboards. Special emphasis should be placed on dimmers,
types of switchboards and the requirements applicable to each. Section 520.27 covers
Stage Switchboard feeders.
Part III covers Fixed Stage Equipment such as Footlights, Border and Proscenium
Sidelights. Requirement for footlights, border and proscenium sidelights should be
covered. Cover the requirement for Receptacles, Curtain motors and Flue damper controls.
Part IV covers Portable Switchboard on stage. Emphasis should be placed on requirements
for Road and Show Connection Panel (a type of Patch Panel). Supply overcurrent
protection, and feeders for portable switchboards are covered under 520.51, 52 & 53.
Emphasize Circuit protection (D) and supply conductors (H). Section (K) covers
protection of supply conductors and connectors.
Part V covers Portable Stage Equipment. Cover the requirements for portable plugging
boxes and bracket fixture wiring. Attention should be given to conductors for portable
stage equipment.
2014 NEC Instructors Manual and Student Worksheets – Level 2 112
Part VI covers Dressing rooms. Special emphasis should be placed on he prohibition of
pendant lampholders, the requirements for lamp guards and the required switches (520-71,
72, 73).
Part VII covers Grounding.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 113
THEATERS AND SIMILAR LOCATIONS
ARTICLE 520
Level II
WORKSHEET
1. The permitted fixed wiring method of theaters shall be which of the following?
a. metal raceways
b. nonmetallic raceways encased in at least 2” concrete
c. type MI or MC cable
d. all of the above
2. Footlights, border lights, and proscenium sidelights shall be arranged so that no branch
circuit will carry a load exceeding which of the following?
a. 15 amperes
b. 20 amperes
c. 30 amperes
d. 100 amperes
3. The supply to a portable switchboard shall be by means of which of the following?
a. rigid metal conduit
b. NM cable
c. nonmetallic conduit
d. extra hard usage cords or cables
4. Which of the following is/are correct concerning lamps and/or lampholders in dressing
rooms?
I. Pendant lampholders shall not be installed in dressing rooms.
II. All lights in dressing rooms shall be controlled by wall switches installed in the
dressing room.
a. I only
b. II only
c. Both I and II
d. Neither I nor II
2014 NEC Instructors Manual and Student Worksheets – Level 2 114
5. In high temperature applications concerning portable stage equipment, which of the
following is correct?
I. A special assembly of conductors shall be permitted to be employed in lieu of flexible
cord if the individual wires are rated not less than 125°C and the outer sleeve is glass
fiber with a wall thickness of at least .025 inches.
II. No special assembly is permitted.
a. I only
b. II only
c. Both I and II
d. Neither I nor II
2014 NEC Instructors Manual and Student Worksheets – Level 2 115
THEATERS AND SIMILAR LOCATIONS
ARTICLE 520
Level II
ANSWER KEY
1. d, all the above 520.5
2. b, 20 amperes 520.41
3. d, extra hard usage cords or cables 520.53(H)(1)
4. c, Both I and II 520.71 & 520.73
5. a, I only 520.68(A)(3)
2014 NEC Instructors Manual and Student Worksheets – Level 2 116
CONTROL SYSTEMS FOR PERMANENT AMUSEMENT ATTRACTIONS
ARTICLE 522
LEVEL II
OBJECTIVE:
After completing this lesson, each student should be familiar with the requirements of Article
522.
MATERIALS:
Examples of control circuit power sources and control circuit conductors for electrical
equipment, including associated control wiring in or on all structures that are an integral part of a
permanent amusement attraction.
INTRODUCTION:
This article covers the requirement for Control Systems for Permanent Amusement Attractions.
PRESENTING THE LESSON:
Part I covers the scope of requirements for installation of control circuit power sources and
control circuit conductors for electrical equipment, including associated control wiring in or on
all structures that are an integral part of a permanent amusement attraction. There are specific
definitions that are integral with this Section. Note the references to "ride devices" and the
specific relevance to this Article and its reference to the application of other Code Articles. Part
II covers the installation requirements for power sources, circuits and wiring methods. Part III
covers the control circuit wiring methods, conductor sizing, overcurrent, and location, grounding
and wet location requirements.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 117
CONTROL SYSTEMS FOR PERMANENT AMUSEMENT ATTRACTIONS
ARTICLE 522
LEVEL II
WORKSHEET
1. What is the ampacity of a #18 AWG copper conductor used in a control circuit at a permanent
amusement attraction?
a. 7 amps
b. 9 amps
c. 11 amps
d. 15amps
2. Control voltage shall be a maximum of which of the following.
a. 150 volts ac volts to ground
b. 300 volts dc volts to ground
c. Neither a nor b
d. Both a and b
3. Non–power-limited control circuits shall not exceed which of the following?
a. 150 volts
b. 250 volts
c. 1,000 volts
d. 300 volts
2014 NEC Instructors Manual and Student Worksheets – Level 2 118
CONTROL SYSTEMS FOR PERMANENT AMUSEMENT ATTRACTIONS
ARTICLE 522
LEVEL II
ANSWER KEY
1. a, 7 amps Table 522.22
2. d, both a and b 522.5
3. d, 300 volts 522.10(B)
2014 NEC Instructors Manual and Student Worksheets – Level 2 119
CARNIVALS, CIRCUSES, FAIRS, AND SIMILAR EVENTS
ARTICLE 525
LEVEL II
OBJECTIVE:
After completing this lesson, each student should be familiar with the requirements of Article
525.
MATERIALS:
Pictures of power supply equipment.
INTRODUCTION:
This article covers the requirement for Carnivals, Circuses, Fairs, and Similar Events.
PRESENTING THE LESSON:
Section I covers the general requirements and other articles.
Section II covers power sources.
Section III covers wiring methods.
Section IV covers grounding and bonding.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 120
CARNIVALS, CIRCUSES, FAIRS, AND SIMILAR EVENTS
ARTICLE 525
LEVEL II
WORKSHEET
1. Which article applies to permanent structures?
a. Article 519
b. Article 520
c. Article 810
d. Article 518
2. Each portable structure shall be provided with a disconnect means located within sight
and within what distance of the operator’s station.
a. 50 ft
b. 25 ft
c. 10 ft
d. 6 ft
3. The ground-fault circuit interrupter shall be permitted to be an integral part of the
attachment plug or located within what distance of the attachment plug.
a. 6 inches
b. 12 inches
c. 18 inches
d. 10 inches
2014 NEC Instructors Manual and Student Worksheets – Level 2 121
CARNIVALS, CIRCUSES, FAIRS, AND SIMILAR EVENTS
ARTICLE 525
LEVEL II
ANSWERS
1. d, Article 520 and Article 518 525.3(B)
2. d, 6 ft. 525.21(A)
3. b. 12 inches 525.23(A)
2014 NEC Instructors Manual and Student Worksheets – Level 2 122
MOTION PICTURE PROJECTORS
ARTICLE 540
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the requirements of
areas in motion picture projectors.
INTRODUCTION:
This article applies to projection rooms, projectors and their associated equipment that
develop hazardous gases.
PRESENTING THE LESSON:
Professional projectors are those using 35 or 70 millimeter film with a minimum of 1
3/8” and have on each edge 5.4 perforations per inch. All others are non-professional.
Projection rooms shall be of permanent construction approved for the type of building
with glass over the projection port.
Those items listed in 540.11(A) shall be located in a separate room or located so that arcs
or sparks will not get to the film. Switches and overcurrent devices shall not be located
in projection rooms.
Picture projectors, spotlights, floodlights and similar equipment shall have a clear work
space of 30".
Conductors supplying outlets for arc or Xenon projectors of the professional type shall
not be smaller than #8.
Conductors used on all lamps or other equipment with operating temperature over 50o C
shall have insulation designed for no less than 200 degrees Centigrade.
Flexible cords are to be hard usage type cords.
Projector enclosures for arc and Xenon lamps, and rectifiers, transformers, etc. shall be
approved.
Non professional equipment shall be approved but not required to be in a
projection room.
2014 NEC Instructors Manual and Student Worksheets – Level 2 123
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 124
MOTION PICTURES PROJECTORS
ARTICLE 540
Level II
WORKSHEET
1. Professional Projectors must use which of the following types of film?
a. 35 millimeter
b. 70 millimeter
c. 120 millimeter
d. Both a and b
2. Where nitrate film is used, motor generator sets, transformers, rectifiers, rheostats, and
Similar equipment for the supply or control of current to projection or spotlight
equipment shall be located in which of the following?
a. A separate room.
b. A film closet.
c. A film vault.
d. A projector vault.
3. Each motion picture projector, floodlight, spotlight, or similar equipment shall have clear
working space not less than
a. 30 inches wide on each side and at the rear thereof.
b. 48 inches wide on each side and at the rear thereof.
c. 52 inches wide on each side and at the rear thereof.
d. 60 inches wide on each side and at the rear thereof.
2014 NEC Instructors Manual and Student Worksheets – Level 2 125
MOTION PICTURE PROJECTORS
ARTICLE 540
Level II
ANSWER KEY
1. d, both a and b (35, 70) 540.2
2. a, a separate room 540.11(A)
3. d, 30 inches wide 540.12
2014 NEC Instructors Manual and Student Worksheets – Level 2 126
MARINAS AND BOATYARDS
ARTICLE 555
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the general
requirements of electrical installation in Marinas and Boatyards.
INTRODUCTION:
The number of installations covered by Article 555 is increasing rapidly and the
importance of proper understanding and application of these safety regulations cannot be
over emphasized. There have been a number of electrocutions on such installations in
North Carolina that could have been avoided provided applicable safety requirements had
been incorporated in the original installation. Maintenance of these installations is also a
very important part of the "safety package."
Many of the recreational facilities covered in the scope of Article 555 will be found in
locations where corrosion is a very difficult problem. Samples of outdoor equipment
which has been designed and listed for such use will be helpful when evaluating proper
application of the necessary components.
PRESENTING THE LESSON:
The scope and application of other Articles in Section 555.1 and 555.2 need to be
reviewed with the students. Also the requirement included in Section 210.8 (B).
The requirements in Section 555.19 cover receptacles which are divided into two classes
of use; 1. Those which provide shore power to the boats and 2. Those which are for use
in maintenance and other purposes. The safety regulation for each is different and
consequently must be thoroughly understood.
Section 555.12, and 555.17 include safety requirements pertaining to the minimum sizing
requirements for branch circuits, feeders and services.
Permitted wiring methods are given in Section 555.13 and should be thoroughly
discussed.
A great deal of emphasis should be placed on covering the grounding requirements
included in Section 555.15 Applicable requirements in Article 250 should also be
reviewed.
Wiring over and under navigable water is subject to the approval of governmental
agencies, such as the Coast Guard.
2014 NEC Instructors Manual and Student Worksheets – Level 2 127
The requirements included in Sections 555.21 pertaining to Gasoline Dispensing and
should be reviewed carefully.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 128
MARINAS AND BOATYARDS
ARTICLE 555
Level II
WORKSHEET
1. Which of the following is/are correct concerning shore power receptacles installed at a
marina or boatyard?
I. All shore power receptacles rated 30 to 50 amperes shall be of locking and grounding
type.
II. All shore power receptacles shall be protected by ground-fault circuit interrupter.
a. I only
b. II only
c. Both I and II
d. Neither I or II
2. Which of the following is/are correct concerning 125 volt, 15 and 20 amp convenience
type receptacles installed at a marina or boatyard?
I. All 125 volt, 15 and 20 amp convenience receptacles shall be protected by ground-
fault circuit interrupters.
II. All 125 volt, 15 and 20 amp convenience receptacles shall be of locking and
grounding type.
a. I only
b. II only
c. Both I and II
d. Neither I or II
3. Twenty shore power receptacles rated 20 amperes and 120 volts will be supplied from
one panel. The minimum ampacity for the 120/240 volt feeder is:
a. 140 amps
b. 280 amps
c. 200 amps
d. 400 amps
2014 NEC Instructors Manual and Student Worksheets – Level 2 129
4. When grounding metal boxes and cabinets at a Marina which of the following is the
minimum size of equipment grounding conductor permitted?
a. #142 insulated copper
b. #12 insulated aluminum
c. #12 insulated conductor
d. #102 bare copper
5. Under what conditions can service equipment be installed on a floating dock or
marina?
a. Floating Piers
b. Boat Docks
c. Marinas
d. None of these
2014 NEC Instructors Manual and Student Worksheets – Level 2 130
MARINAS AND BOATYARDS
ARTICLES 555
Level II
ANSWER KEY
1. a 555.19(A)(4)
2. a 555.19(B)(1)
3. a, 20 x 20 x 120 = 48,000 x 70% = 33,6 00/240 V = 140 amps Table 555.12
4. c 555.15(C)
5. d 555.7
2014 NEC Instructors Manual and Student Worksheets – Level 2 131
MANUFACTURED WIRING SYSTEMS
ARTICLE 604
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the uses and construction of
manufactured wiring systems.
INTRODUCTION:
This article applies to field-installed wiring using off-site manufactured subassemblies for
branch circuits, remote-control circuits, signaling circuits and communication circuits in
accessible areas. Also, a manufactured wiring system is defined as: a system containing
component parts that are assembled in the process of manufacture and cannot be inspected at
the building site without damage or destruction to the assembly and used for the connection of
luminaires, utilization equipment, continuous plug-in type busways and other devices.
PRESENTING THE LESSON:
These systems are permitted to be used in accessible and dry locations and in plenums and
spaces used for environmental air when appropriate. Also, installation must comply with
Section 300.22. Review the many articles that affect or limit the use of such systems.
Stress the specifications of cable [Section 604.6(A)] and conduit types [Section 604.6(B)] and
review the specifications for receptacles and connectors in Section [604.6 (C)]
Any unused outlet should be capped to effectively close the connector openings.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 132
MANUFACTURED WIRING SYSTEMS
ARTICLE 604
Level II
WORKSHEET
1. Manufactured wiring systems shall be permitted in which of the following?
a. Accessible and dry locations.
b. Ducts and plenums.
c. Air-handling spaces where listed for this application.
d. All of the above.
2. Cable shall be listed armored cable or metal-clad containing nominal 600-volt:
a. No. 10 AWG copper insulated conductors with a bare No. 12 AWG
copper equipment grounding conductor.
b. No. 12 AWG copper insulated conductors with a bare No. 12 AWG
copper equipment grounding conductor.
c. No. 12 AWG aluminum insulated conductors with a bare No. 12 AWG
aluminum equipment grounding conductor.
d. No. 12 AWG copper insulated conductors with a bare No. 14 AWG
copper equipment grounding conductor.
3. Without exception conduit shall be listed flexible metal conduit containing nominal 600-
volt:
a. No. 12 AWG copper insulated conductors with an insulated or bare No. 12
AWG copper equipment grounding conductor.
b. No. 12 AWG copper insulated conductors with an insulated or bare No. 10
AWG copper equipment grounding conductor.
c. No. 10 AWG copper insulated conductors with an insulated or bare No. 8
AWG copper equipment grounding conductor.
d. No. 10 AWG copper insulated conductors with an insulated or bare No. 12
AWG copper equipment grounding conductor.
4. Which of the following is/are correct concerning receptacles and connectors in
manufacturing wiring systems?
I. Receptacles and connectors shall be locking type.
II. Receptacles and connectors shall be identified for this purpose.
a. I only
b. II only
c. Both I and II
d. Neither I nor II
2014 NEC Instructors Manual and Student Worksheets – Level 2 133
MANUFACTURED WIRING SYSTEMS
ARTICLE 604
Level II
ANSWER KEY
1. d, all of the above 604.4
2. b 604.6(A)(1)
3. a 604.6(A)(2)
4. c 604.6(BC)
2014 NEC Instructors Manual and Student Worksheets – Level 2 134
ELEVATORS, DUMBWAITERS, ESCALATORS, AND MOVING WALKS
ARTICLE 620
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar the requirements of Article 620
for Elevators, Dumbwaiters, Escalators and Moving Walks.
INTRODUCTION:
This article covers the installation of electric equipment and wiring used in connection with
elevators, dumbwaiters, escalators and moving walks.
PRESENTING THE LESSON:
Part I covers definitions; voltage limitations for operating control and signaling circuit and for
motors, brakes and motor generator sets; and working clearances.
Part II covers the conductors installed for use with equipment covered in Article 620. Place
emphasis on the flame retardant requirement for insulation of conductors and the permitted
types. Also cover the minimum size conductors as covered in Article 620.12 & 13. Go
through an overhead of figure 620.13.
Part III covers the permitted wiring methods in this article. Place emphasis on these
requirements. Also place emphasis on the branch circuits for car lighting, receptacle(s),
ventilation, branch circuit for machine room machinery spaces, lighting and receptacles; and
branch circuit for hoistway pit lighting and receptacle(s).
Part IV covers the installation of conductors. Emphasize the different limitations for wireways
and auxiliary gutters. Special emphasis should be placed on 620.37 Wiring in Hoistways; uses
permitted and lighting protection. Refer to Article 511 for wiring in Hazardous Locations.
Part V covers Traveling Cables.
Part VI covers the Disconnecting Means and Control. Special emphasis should be placed on
the requirements for a single means for disconnecting all ungrounded conductors for each unit
including the control value operating magnets. This disconnect shall not disconnect the
required branch circuits in 620.22 through 620.24. The location of this disconnect shall be
where readily accessible to qualified persons.
Part VII covers Overcurrent Protection. Overcurrent protection for operating devices and
controls shall be provided as covered in Articles 725.43 and 725.45 and for motors in Article
430.33. Highlight this article is one of those within the NEC (others include Articles 517, 700,
and 708) that mandate selective coordination and is applicable where more than one machine is
supplied by a single feeder.
2014 NEC Instructors Manual and Student Worksheets – Level 2 135
Part VIII covers the Machine Room. This room shall be secured. Make note of where motor
controllers and driving machines can be located.
Part IX covers grounding and refers to Article 250 and part X covers emergency and standby
power systems.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 136
ELEVATORS, DUMBWAITERS, ESCALATORS, AND MOVING WALKS
ARTICLE 620
Level II
WORKSHEET
1. In general, the nominal voltage for operating control and signaling circuits for elevators
shall not exceed which of the following?
a. 150 volts
b. 250 volts
c. 300 volts
d. 600 volts
2. The minimum size of conductors used for elevator traveling cables when used for
lighting and installed in parallel is which of the following provided the ampacity is
equivalent to at least #14 AWG wire?
a. #14 AWG
b. #16 AWG
c. #20 AWG
d. #24 AWG
3. A separate circuit is required to supply which of the following in an elevator car?
a. car lights
b. receptacle(s)
c. car ventilation
d. all the above
4. Feeders supplying power to elevators and dumbwaiters shall meet which of the
following?
A) shall be installed inside the hoistway.
B) shall be permitted within an existing hoistway without splices by special permission.
a. A only
b. B only
c. both A & B
d. neither A or B
2014 NEC Instructors Manual and Student Worksheets – Level 2 137
5. Which statement is not true concerning disconnect means for the main power supply:
a. Single means provided to disconnect all ungrounded power supply
conductors for each unit.
b. Disconnect be so designed that no pole can be operated independently
c. Where multiple driving machines are connected to a single elevator, there shall be
one disconnect to disconnect the motor and control valve and operating magnets.
d. The disconnecting means for the main power supply conductors shall
disconnect the branch circuit for a car light.
6. Which of the following is/are correct concerning the elevator equipment disconnecting
means?
I. The disconnecting means shall be installed in a room set aside for that purpose.
II. The room for the disconnecting means does not have to be secured
against unauthorized access.
a. I only
b.II only
c. Both I & II
d.Neither I or II
2014 NEC Instructors Manual and Student Worksheets – Level 2 138
ELEVATORS, DUMBWAITERS, ESCALATORS, AND MOVING WALKS
ARTICLE 620
Level II
ANSWER KEY
1. c, 300 volts 620.3
2. c, #20 620.12(A)(1)
3. d, all of the above 620.22(A)
4. b, B only 620.37(C)(1)
5. d, The disconnecting means for the main power
supply conductors shall disconnect the branch
circuit for a car light. 620.51
6. a, I only 620.71
2014 NEC Instructors Manual and Student Worksheets – Level 2 139
ELECTRIC VEHICLE CHARGING
SYSTEM EQUIPMENT
ARTICLE 625
LEVEL II
OBJECTIVE:
After completing this lesson, each student should be familiar with the requirement for equipment
and wiring, external to an electric vehicle, that connect an electric vehicle to a supply of
electricity.
INTRODUCTION:
This Article covers the equipment and wiring requirements for installation of equipment and
devices related to electric vehicle charging.
PRESENTING THE LESSON:
Make note of wiring method 625.10 Equipment Construction , 625.40 Overcurrent
Protection, Also make note of 625.42 Disconnecting Means
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 140
ELECTRIC VEHICLE CHARGING
SYSTEM EQUIPMENT
ARTICLE 625
LEVEL II
WORKSHEET
1. Which one of the following electric vehicles would be covered under Article 625.
a. Golf Carts
b. Electric Motorcycles
c. Passenger Buses
d. Boats
2. All electrical materials, devices, fittings, and associated equipment shall meet which of
the following?
a. Made in USA
b. Approved by local inspector
c. Approved for that vehicle only
d. Listed or labeled
3. An electric vehicle supply connector shall be provided with a grounding pole
that shall be configured to connect with the mating inlet in which of the following
manners?
a. first to make and last to break
b. the same make and type
c. in the same location
d. connect vertically
4. Overcurrent protection for feeders and branch circuits supplying electric vehicle supply
equipment shall be sized at which of the following?
a. 80%
b. 115%
c. 125%
d. 75%
5. For electric vehicle supply equipment rated more than 60 amperes or more than 150 volts
to ground, the disconnecting means shall meet which of the following?
a. Be installed in an accessible location
b. Be installed not less than 18 in. and not more than 4 ft. above floor level.
c. Be rated at 115% of connected load
d. Be installed in a readily accessible location.
2014 NEC Instructors Manual and Student Worksheets – Level 2 141
ELECTRIC VEHICLE CHARGING
SYSTEM EQUIPMENT
ARTICLE 625
LEVEL II
ANSWER KEY
1. c, passenger buses 625.2
2. d, listed or labeled 625.5
3. a, first to make and last to break 625.10 F
4. c, 125% 625.40
5. d, be installed in a readily accessible location 625.42
2014 NEC Instructors Manual and Student Worksheets – Level 2 142
ELECTRIC WELDERS
ARTICLE 630
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar the requirement for electric arc
welding, resistance welding apparatus and similar welding equipment.
MATERIALS NEEDED:
Slides or transparencies of nameplates from several types of welders as well as Transparencies
of Duty Cycle tables.
INTRODUCTION:
This article covers the requirements for AC Transformers, DC Rectifier Welders, Motor
Generator Arc Welders, Resistance Welders and Welding Cable.
PRESENTING THE LESSON:
Part II covers the requirements for Arc Welders. Go over the requirements for sizing the
conductors that supply these welders. Emphasize the "duty cycle" for an individual and a
group of welders. Cover the requirements for overcurrent protection and disconnecting means.
Part III covers the requirements for Resistance Welders. Go over the requirements for sizing
the conductors, overcurrent protection and disconnecting means. Emphasize calculations using
"duty cycle"
Part IV covers the requirements for Welding Cable.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 143
ELECTRIC WELDERS
ARTICLE 630
Level II
WORKSHEET
1. What ampacity conductors would be required for an AC transformer type welder with a
primary current rating of 100 amps and a duty cycle of 50?
a. 100 amperes
b. 91 amperes
c. 88 amperes
d. 71 amperes
2. Four AC transformer type welders rated 50, 35, 30, and 20 amperes are connected on the
same circuit. The circuit conductors shall be considered ample when rated which of the
following minimum amperes?
a. 135 amperes
b. 124 amperes
c. 116 amperes
d. 97 amperes
3. Which of the following is the supply conductor size for a resistance welder with a
primary current of 100 amperes and a duty cycle of 30% if the supply conductor is
THW copper?
a. # 4
b. # 6
c. # 8
d. # 10
2014 NEC Instructors Manual and Student Worksheets – Level 2 144
ELECTRIC WELDERS
ARTICLE 630
Level II
ANSWER KEY
1. d. 71 amperes Table [630.11(A)(2)
Duty cycle is 50 which has multiplier of .71 times the rated primary current 100 equals
71
amperes.
2. b. 124 amperes [630.11(B)]
Use 100% of the two largest 50 + 35 x 100% = 85 Amperes
Use 85% of the third largest 30 x 85% = 25 Amperes
Use 70% of the fourth largest 20 x 70% = 14 Amperes
124 Amperes
3. b. 55 amperes [630.31(A)(2)] and 310.15( B) (16)
Multiplier for 30% duty cycle is .55 times 100 Amperes = 55 Amperes
2014 NEC Instructors Manual and Student Worksheets – Level 2 145
AUDIO SIGNAL PROCESSING, AMPLIFICATION,
AND REPRODUCTION EQUIPMENT
ARTICLE 640
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar the requirement for equipment
and wiring for sound recording and similar equipment.
INTRODUCTION:
This Article covers the equipment and wiring requirements for sound-recording and
reproduction, centralized distributions of sound, public address, speech-input system and
electronic organs.
PRESENTING THE LESSON:
Note that this Article refers to other Sections of the NEC. Note the exceptions that modify
these other Sections in 640.2, 3, and 4. Note the requirement concerning conductors, flexible
cords and storage batteries. Note the circuit overcurrent protection requirements.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 146
AUDIO SIGNAL PROCESSING, AMPLIFICATION,
AND REPRODUCTION EQUIPMENT
ARTICLE 640
Level II
WORKSHEET
1. All wiring not connected to the premises shall comply with:
a. Chapters 1-4
b. Article 480
c. Article 647
d. Article 725
2. Flexible cords and cables to and between permanent audio systems shall comply with
which of the following articles?
a. Article 725.
b. Article 110
c. Article 647
d. Article 310.16
3. Wireways and auxiliary gutters shall be grounded and bonded in accordance with the
requirements of Article 250. Where the wireway or auxiliary gutter does not contain
power-supply wires, the equipment grounding conductor shall not be required to be larger
than which of the following?
a. # 14 AWG
b. # 12 AWG
c. # 10 AWG
d. # 6 AWG
4. In portable audio systems, installation shall comply with which of the following Articles?
a. 480
b. 647
c. 300
d. 400
2014 NEC Instructors Manual and Student Worksheets – Level 2 147
AUDIO SIGNAL PROCESSING, AMPLIFICATION,
AND REPRODUCTION EQUIPMENT
ARTICLE 640
Level II
ANSWER KEY
1. d, Article 725 640.9 (A)(3)
2. a. Article 725 640.21(C)
3. a. # 14 AWG 640.7(A)
4. d, Article 400 640..42(C)
2014 NEC Instructors Manual and Student Worksheets – Level 2 148
INFORMATION TECHNOLOGY EQUIPMENT
ARTICLE 645
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar the requirements concerning
electronic computer/data processing equipment and system.
INTRODUCTION:
This article covers equipment, power-supply wiring, equipment interconnecting wiring, and
grounding of electronic computer/data processing equipment and systems, including electronic
computer/data processing equipment and systems used as a terminal unit in an electronic
computer/data processing room.
PRESENTING THE LESSON:
Branch circuit conductors that have data processing units on the line shall have an ampacity not
less than 125 percent of the total connected load. (645.5)
Review the requirements of connecting cables of data processing systems. Also, note that
when such cables are run on the floor that they shall be protected against physical damage.
[645.5(C)]
Discuss the conditions under which power cables, communication cables, etc. shall be allowed
under raised floors. [645.5(D)]
Explain the requirements for disconnecting means in Section 645-10 and note that there may
be a single means permitted to control both the electronic equipment and the air conditioning
system.
All exposed metal parts of a data processing system shall be grounded in accordance with
Article 250(D). A data processing unit designed to be supplied by a branch circuit shall be
provided with a manufacturer's nameplate which includes the rating in volts, operating
frequency and total load in amperes.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 149
INFORMATION TECHNOLOGY EQUIPMENT
ARTICLE 645
Level II
WORKSHEET
1. Branch circuit conductors that have data processing units on the line shall have an
ampacity not less than what percent of the total connected load.
a. 80%
b. 100%
c. 115%
d. 125%
2. If connecting cables of data processing systems are run on the surface of the floor they
shall be protected against which of the following?
a. Moisture damage
b. Physical damage
c. Overheating from lighting
d. Ultra-violet damage
3. The branch circuit supply conductors to receptacles under raised floors shall be
In which of the following?
a. rigid metal conduit
b. metal wireway
c. flexible metal conduit
d. all of the above
4. Which of the following is/are correct concerning the disconnecting means for electronic
equipment in a data processing room?
I. The disconnecting means shall be readily accessible to the operator at the principal exit
doors.
II. A single means to control both the electronic equipment and air-conditioning system
shall be permitted.
a. I only
b. II only
c. Both I and II
d. Neither I nor II
2014 NEC Instructors Manual and Student Worksheets – Level 2 150
INFORMATION TECHNOLOGY EQUIPMENT
ARTICLE 645
Level II
ANSWER KEY
1. d, 125% 645.5(A)
2. b, physical damage 645.5(B & C)
3. d, all of the above 645.5(D)(2)
4. c, Both I and II 645.10
2014 NEC Instructors Manual and Student Worksheets – Level 2 151
PIPE ORGANS
ARTICLE 650
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with regulations concerning the
energy source, insulation, conductors, and installation of conductors and overcurrent protection
of organs.
INTRODUCTION:
This article covers the electric circuits and parts of electrically operated organs which are used
for control of the sounding apparatus and keyboards. Such organs shall also comply with the
appropriate provisions of Article 640.
PRESENTING THE LESSON:
Discuss the source of energy requirements for organs. (650.3)
Explain the insulation requirements for grounding or specific parts. Conductors shall be No.
26 or larger and the common-return conductor shall be No. 14 or larger. The insulation of such
conductors shall be of rubber, thermoplastic, cotton, or silk insulation. Note the exception for
the insulation of the common return conductors.
Discuss the conductors to be cabled and cable coverings in Section [650.5(C & D)].
Cables may be attached directly to the organ structure without insulating supports, but may not
be placed in contact with other conductors. (650.6)
All conductors shall be arranged so that they are protected by an overcurrent device rated at not
over 6 amperes. (650.7)
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 152
PIPE ORGANS
ARTICLE 650
Level II
WORKSHEET
1. The source of energy shall have a potential of not over which of the following?
a. 15 volts ac
b. 15 volts dc
c. 30 volts ac
d. 30 volts dc
2. Conductors shall be not less than which of the following for electronic signal circuits?
a. 28 AWG
b. 26 AWG
c. 14 AWG
d. 30 AWG
3. Conductors shall have which of the following type of insulation?
a. Thermoplastic
b. Thermosetting
c. Neither a or b
d. Either a or b
4. Where not installed in metal raceway, the covering shall be which of the following?
a. Resistant to insects.
b. Resistant to Flame spread
c. Resistant to Ultra-violet light
d. Resistant to Thermal overload
5. Cables shall be securely fastened in place and shall be permitted to be attached directly
to the organ structure without which of the following?
a. Insulating supports.
b. Conductor supports.
c. Thermal overload.
d. Overload Resistors.
2014 NEC Instructors Manual and Student Worksheets – Level 2 153
PIPE ORGANS
ARTICLE 650
Level II
ANSWER KEY
1. d, 30 volts dc 650.3
2. a, 28 AWG 650.5(A)
3. d, Either a or b 650.6(B)
4. d, Resistant to flame-spread 650.5(D)
5. a, Insulating supports. 650.7
2014 NEC Instructors Manual and Student Worksheets – Level 2 154
INDUSTRIAL MACHINERY
ARTICLE 670
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar the definition, nameplate
data, overcurrent protection, and supply conductors for industrial machinery.
INTRODUCTION:
Take this time to go over the definitions of industrial machinery (machine) and industrial
manufacturing system.
PRESENTING THE LESSON:
A permanent nameplate shall be attached to the control equipment enclosure or machine and
shall be plainly visible after installation. The nameplate shall include the following
information:
(1) Supply voltage, phase, frequency, and full-load current
(2) Maximum ampere rating of the short-circuit and ground-fault protective device
(3) Ampere rating of largest motor, from the motor nameplate, or load
(4) Short circuit current rating of the machine industrial control panel based on one of
the following:
a. Short circuit current rating of a listed and labeled machine control enclosure or
assembly
b. Short circuit current rating established utilizing an approved method
FPN: UL 508A-2001, Supplement SB, is an example of an approved method.
(5) Electrical diagram number(s) or the number of the index to the electrical drawings
[670.3(A)]
Discuss the rating of the full-load current for different combinations of motors. The machine
shall be marked "overcurrent protection provided at machine supply terminals," when
overcurrent protection is provided in accordance with Section [670.4(B)].
Discuss how the size of supply conductors shall be determined as indicated by Section
[670.4(A)] Also cover fine print notes (FPN).
As far as overcurrent protection is concerned, a machine shall be considered as an individual
unit and therefore shall be provided with a disconnecting means. Discuss the requirements for
disconnecting means for industrial machinery.
2014 NEC Instructors Manual and Student Worksheets – Level 2 155
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 156
INDUSTRIAL MACHINERY
ARTICLE 670
Level II
WORKSHEET
1. This article covers which of the following pertaining to the supply conductors to
industrial machinery?
a. The definition of.
b. The size and overcurrent protection
c. The nameplate data for.
d. All of the above
2. Machine nameplate data should include which of the following except?
a. Supply voltage, phase, frequency, and full-load current
b. Maximum ampere rating of the short-circuit and ground-fault protective
device.
c. Ampere rating of largest motor, from the motor nameplate, or load
d. Fault current rating of the listed control panel.
3. The supply conductor shall have an ampacity not less than what percent of the full-load
current
rating of all heating loads plus what percent of the full-load current rating of the highest
rated motor plus the sum of the full-load current ratings of all other connected motors
which may be in operation at the same time?
a. 100 %, 125%
b. 125%, 100 %
c. 100%, 100 %
d. 125%, 125%
2014 NEC Instructors Manual and Student Worksheets – Level 2 157
INDUSTRIAL MACHINERY
ARTICLE 670
Level II
ANSWER KEY
1. d, all of the above 670.1
2. d, fault current rating of the control panel 670.3
3. d, 125%, 125% 670.4
2014 NEC Instructors Manual and Student Worksheets – Level 2 158
ELECTRICALLY DRIVEN OR CONTROLLED IRRIGATION MACHINES
ARTICLE 675
Level II
OBJECTIVE:
After completing this lesson, each student should understand the definition of irrigation
machines and definitions related to the equipment.
MATERIALS NEEDED:
Samples of conductor used, types of disconnects.
INTRODUCTION:
Explain to students that you will briefly cover the article, cover the most important sections.
This type of installation is not seen often, and a short period of time should be spent on the
article.
PRESENTING THE LESSON:
Discuss code sections, touch on wiring methods and materials used. Discuss certain code
sections that would be found more often in field, for example: types of wires permitted, sizes
of conductors, disconnecting mean and grounding of equipment.
APPLICATION:
If time will allow, let the class have time to answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 159
ELECTRICALLY DRIVEN OR CONTROLLED IRRIGATION MACHINES
ARTICLE 675
Level II
WORKSHEET
1. The cable used to interconnect enclosures on the structure of an irrigation machine shall
be of a type approved for use in wet locations and have a minimum temperature rating
of?
a. 60° C
b. 75° C
c. 85° C
d. 90° C
2. The cables used to interconnect enclosures on irrigation equipment shall be supported at
intervals not to exceed which of the following?
a. 2 feet
b. 3 feet
c. 4 feet
d. 6 feet
3. The main disconnecting means for irrigation equipment shall be a maximum distance
from the equipment of which of the following?
a. 10 feet
b. 25 feet
c. 50 feet
d. In sight
4. Cords used on irrigation machines shall have an equipment grounding conductor as an
integral part of the cord, the equipment grounding conductor shall not be smaller than?
a. largest cord supply conductor
b. #16 copper
c. #14 copper
d. sized according to 250.122
2014 NEC Instructors Manual and Student Worksheets – Level 2 160
5. A disconnecting means in sight from the machine and 20 feet away shall meet which of
the following requirements?
I. Shall be capable of being locked in the open position.
II. Shall be readily accessible.
a. I only.
b. II only.
c. Neither I or II
d. Both I and II
2014 NEC Instructors Manual and Student Worksheets – Level 2 161
ELECTRICALLY DRIVEN OR CONTROLLED IRRIGATION MACHINES
ARTICLES 675
Level II
ANSWER KEY
1. b 675.4(A)
2. c 675.4(C)
3. d 675.8(B)
4. a 675.13
5. d 675.8(B)
2014 NEC Instructors Manual and Student Worksheets – Level 2 162
INTEGRATED ELECTRICAL SYSTEMS
ARTICLE 685
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the location of overcurrent
devices, direct-current system grounding, and ungrounded control circuits of integrated
electrical systems.
INTRODUCTION:
An integrated electrical system is a unitized segment of an industrial wiring system where all
of the following conditions are met:
(1) An orderly shutdown is required to minimize personnel hazard and equipment damage.
(2) The conditions of maintenance and supervision ensure that qualified persons service the
system. The name(s) of the qualified person(s) shall be kept in a permanent record at the
office of the establishment in charge of the completed installation.
A person designated as a qualified person shall possess the skills and knowledge related
to the construction and operation of the electrical equipment and installation and shall
have received documented safety training on the hazards involved. Documentation of
their qualifications shall be on file with the office of the establishment in charge of the
completed installation.
(3) Effective safeguards acceptable to the authority having jurisdiction are established and
maintained
PRESENTING THE LESSON:
Explain how overcurrent devices shall be accessible but mounted at heights that assure security
form operation by non-qualified personnel. Note that two-wire direct-current circuits shall be
permitted to be ungrounded. (685.12)
Explain that, where operational continuity is required, control circuits of 150 volts or less from
separately derived systems shall be permitted to be ungrounded. (685.14)
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results
2014 NEC Instructors Manual and Student Worksheets – Level 2 163
INTEGRATED ELECTRICAL SYSTEMS
ARTICLE 685
Level II
WORKSHEET
1. Which of the following statement is correct regarding integrated electrical systems?
I. Two-wire direct current circuits shall not be permitted to be ungrounded.
II. Overcurrent devices shall be permitted to be accessible with mounting heights allowed to
assure security from operation by unqualified personnel.
a. I only
b. II only
c. I and II
d. neither
2. Where operational continuity is required, control circuits of which of the following volts or
less from separately derived systems shall be permitted to be ungrounded.
a. 100
b. 150
c. 175
d. 200
2014 NEC Instructors Manual and Student Worksheets – Level 2 164
INTEGRATED ELECTRICAL SYSTEMS
ARTICLE 685
Level II
ANSWER KEY
1. b 685.10, 685.12
2. b 685.14
2014 NEC Instructors Manual and Student Worksheets – Level 2 165
FIRE PUMPS
ARTICLE 695
LEVEL II
OBJECTIVE:
After completing this lesson, each student should the definition, overcurrent protection and
supply conductor for fire pumps.
INTRODUCTION:
Note to students the application of other Articles (Chapters 1, 2, 3, and 4). For level II you
should cover section 695.3 and 695.14.
PRESENTING THE LESSON:
Explain to students the purpose of fire pumps and how they should operate under emergency use.
Review chapters 1-4 and how they relate to fire pumps.
Review section 695.3 on power supplied to electric motor-driven fire pumps. Make note to
review exception.
Review section 695.6; supply conductor, wiring method and conductors.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results
2014 NEC Instructors Manual and Student Worksheets – Level 2 166
FIRE PUMPS
ARTICLE 695
LEVEL II
WORKSHEET
1. Power shall be permitted to be supplied to the electric motor driven fire pump by:
(A) Service
(B) On-Site Generation
a. A only
b. B only
c. Neither A or B
d. Both A and B
2. A disconnecting means and overcurrent protective device(s) shall be permitted to be
installed between the power supply and listed fire pump controller. A placard shall be
externally installed on the disconnecting means stating “FIRE PUMP
DISCONNECTING MEANS”. The letters shall be at least which of the following in
height?
a. 1 inch
b. 2 inches
c. ¾ inch
d. ½ inch
3. Where a transformer is dedicated to supplying a fire pump installation, it shall be rated at
a minimum of what percent of the sum of the rated full load of the fire pump motor, plus
what percent of associated accessory equipment?
a. 125% -- 100%
b. 150% -- 175%
c. 175% -- 200%
d. 250% -- 300%
4. The primary overcurrent protective device(s) shall be selected or set to carry the sum of
the locked-rotor current of the fire pump motor(s) for which of the following time periods?
a. 1 hour
b. 2 hours
c. 3 hours
d. Indefinitely
2014 NEC Instructors Manual and Student Worksheets – Level 2 167
5. All electric motor-driven fire pump control wiring shall be in one of the following?
a. Rigid non-metallic conduit
b. Rigid metal conduit
c. Type AC cable
d. Type MC cable
2014 NEC Instructors Manual and Student Worksheets – Level 2 168
FIRE PUMPS
ARTICLE 695
LEVEL II
ANSWER KEY
1. d, Both A and B 695.3(A)(1) and (2)
2. a, 1” 695.4(B)(3)(c)
3. a, 125% -- 100% 695.5(A)
4. d, indefinitely 695.5(B)
5. b, Rigid metal conduit 695.14(E)
2014 NEC Instructors Manual and Student Worksheets – Level 2 169
EMERGENCY SYSTEMS
ARTICLE 700
Level II
OBJECTIVE:
After completing this lesson each student should know what an emergency system is and the
special requirements that are applied when using emergency systems.
INTRODUCTION:
This article applies to the safety of the design, installation, operation, and maintenance of
emergency systems. This also applies to the wiring methods used to supply the required
equipment.
Emergency systems are those legally required by municipal, state, federal, or other codes and
classed as emergency. These systems automatically supply power/or illumination in case of
normal power failure.
(See FPN's under Article 700.1 for further information.)
PRESENTING THE LESSON:
Except as modified in this article all other articles shall apply. All equipment used on
emergency systems shall be approved for that use.
After installation of the emergency systems, the authority having jurisdiction shall require a
test of the system and periodic maintenance thereafter. A written record shall be kept of these
tests.
The capacity of the emergency system shall be adequate to supply all loads to be operated
simultaneously. Alternate power sources shall be permitted to supply legally required and
optional stand-by systems where automatic selective load pick-up and load shedding is
provided as needed to assure adequate power to (1) emergency circuits (2) legally required
standby circuits and (3) optional stand-by circuits, in that order of priority.
Transfer equipment shall be automatic and designed to prevent back feed to normal power
sources and identified for emergency use.
Explain- Audible and visual signal devices shall be provided, where practicable for the
detection of four problem conditions. Explain the four conditions (700.6) and why they need
to be detected. Explain that more detailed information can be found in NFPA 110.1996.
A sign shall be placed at the service equipment indicating type and location of on-site
emergency power sources.
2014 NEC Instructors Manual and Student Worksheets – Level 2 170
All boxes and enclosures for emergency circuits shall be marked as a part of the emergency
systems. In general, all wiring from emergency systems shall be kept separate from all other
wiring and equipment. [See 700.10].
When normal power has been lost the emergency system is required to restore power within 10
seconds. When selecting a source of emergency power take into consideration the occupancy
and type of service to be rendered. Consideration shall also be given to the location and/or
design of equipment to minimize hazards that might cause failure due to floods, fires, icing,
and vandalism.
Storage batteries can be used but must maintain 87 1/2% of normal voltage for 1 1/2 hours.
Generator sets can be used with the following requirements:
1. 15 minute setting to prevent retransfer to normal power
2. Minimum of 2 hour fuel supply
3. Cannot depend solely on public utilities gas or water systems
4. Storage batteries used to start the generator must be approved for purpose and have
automatic charging means.
5. If more than a 10 second time delay must have auxiliary power source to pick up until
generator can take over.
6. The complete set must be acceptable to the authority having jurisdiction.
A separate service complying to Article 230 can be accepted if approved by the authority
having jurisdiction. The service drop or lateral shall be widely separated from the normal
source of power.
Go over requirements in Article 700.12 (F) for unit equipment. Point out it must be fixed in
place and if cord connected must have cord not over 3', must be fed from branch circuit on
normal lighting and fed of any local switch(s). In an uninterrupted area supplied by a
minimum of 3 lighting circuits a separate branch circuit shall be permitted from the same panel
as the normal lighting circuits.
No appliances, lamps or other than those specified as required for emergency use shall be
supplied by emergency lighting circuits.
Emergency Illumination shall be for egress lighting, (700.16) exit signs, and other lights as
necessary. Lights shall be designed so that when a bulb burns out the area will not be left in
total darkness. When high-intensity discharge lighting is used for normal lighting, emergency
lighting must operate until normal illumination has been restored.
Branch circuits supplying emergency lighting must be supplied from a source complying with
700.12 when normal supply is interrupted.
Switches installed on emergency circuits shall be accessible only to authorized persons (see
exceptions). Manual switches shall be located convenient to authorized persons responsible for
their actuation. In places of assembly, a control switch shall be in the lobby or convenient
2014 NEC Instructors Manual and Student Worksheets – Level 2 171
thereto, but never in a projection booth, stage or platform. Branch circuit overcurrent devices
shall be accessible to qualified persons only.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
It time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 172
EMERGENCY SYSTEMS
ARTICLE 700
Level II
WORKSHEET
1. The sensor for ground-fault signal devices shall have a maximum ground fault current
setting of which of the following in amperes?
a. 600 amperes
b. 800 amperes
c. 1000 amperes
d. 1200 amperes
2. A location in which emergency circuits can be located in same enclosures as normal
circuits is which of the following?
a. transfer equipment
b. service equipment
c. receptacle outlets
d. all the above
3. When normal power fails emergency power must pick up within which of the following?
a. 60 seconds
b. 30 seconds
c. 20 seconds
d. 10 seconds
4. Storage batteries must carry full load for a period of not less than which of the following?
a. 30 minutes
b. 1 hour
c. 1 1/2 hour
d. 2 hour
5. A generator set is required to have a time delay of not less than which of the following to
prevent retransfer to normal power?
a. 10 minutes
b. 15 minutes
c. 20 minutes
d. 30 minutes
2014 NEC Instructors Manual and Student Worksheets – Level 2 173
6. A generator is required to have on site fuel supply sufficient for not less than which of the
following for full-demand operation?
a. 1/2 hour
b. 1 hour
c. 1 1/2 hour
d. 2 hour
7. Flexible cord shall be permitted on unit equipment not in excess of which of the
following feet in length?
a. 2 feet
b. 3 feet
c. 4 feet
d. 6 feet
8. Where permitted a separate branch circuit for unit equipment can be fed from?
a. main service panel
b. any panelboard with a lock on feature
c. same panelboard as the normal lighting circuits
d. all of the above
9. All manual switches for controlling emergency circuits shall be in locations convenient to
authorized persons responsible for their actuation. In facilities covered by Articles 518 and
520, a switch for controlling emergency lighting systems shall be:
I- located in the lobby or at a place conveniently accessible thereto.
II- placed in a motion-picture projection booth or on a stage or platform.
a. I only
b. II only
c. both I & II
d. neither I nor II
10. Legally required emergency circuits may be installed with legally required circuits in these
enclosures:
a. Panelboards
b. Individual disconnect enclosure
c. Same vertical switchboard section
d. None of the above
2014 NEC Instructors Manual and Student Worksheets – Level 2 174
EMERGENCY SYSTEMS
ARTICLE 700
Level II
ANSWER KEY
1. d, 1,200 700.5(D)
2. a, transfer equipment 700.10(D)(2)
3. d, 10 seconds 700.12
4. c, 1 1/2 hour 700.12(A)
5. b, 15 minutes 700.12 (B)(1)
6. d, 2 hours 700.12(B)(2)
7. b, 3 700.12(F)
8. c, same panelboard as the normal lighting circuits 700.12(F)
Exc. 1
9. (a) I only 700.21
10. d, 700.9(B)(5)(c)
2014 NEC Instructors Manual and Student Worksheets – Level 2 175
LEGALLY REQUIRED STANDBY SYSTEMS
ARTICLE 701
Level II
OBJECTIVES:
After completing this lesson, each student should know: (1) what Legally Required Standby
Systems are and how they differ from emergency systems. (2) the wiring methods and
equipment included in Legally Required Standby Systems.
INTRODUCTION:
This article is designed to apply to electrical safety of the design, installation, operation, and
maintenance of the circuits and equipment designed to supply power and illumination when
normal power is interrupted. These systems, like emergency systems, are classed by
municipal, state, federal, or other codes or governmental agencies having jurisdiction. They do
not include those listed under emergency systems. (See FPN for list of examples)
PRESENTING THE LESSON:
All equipment used in Legally Required Standby Systems must be approved for the intended
purpose.
The authority having jurisdiction shall see that a test is performed upon completion and
periodically thereafter. Batteries used for starting or ignition of prime movers shall have
periodic maintenance. All these test shall be kept as a permanent record. Means shall be
provided for testing under load.
The system shall be of adequate size to supply the full capacity of all equipment intended to be
used at one time. When automatic selective load pick up and load shedding is provided as an
alternate power source shall be permitted to supply legally required standby systems.
Transfer equipment shall be automatic and identified for standby use or approved by the
authority having jurisdiction. Transfer equipment must be designed to prevent back feed to the
normal power source.
Explain that both audible and visual signals are required (where practicable) for the detection
of three problem conditions. Explain the three conditions (701.5) and why they need to be
detected. More detailed information is available in NFPA 110.
A sign shall be placed at the service entrance to indicate type and location of legally required
standby systems.
Unlike emergency systems legally required standby systems can occupy the same raceway,
junction box, cabinet, etc. as general wiring.
2014 NEC Instructors Manual and Student Worksheets – Level 2 176
Sources of power shall be capable of restoring power within 60 seconds of loss of normal
power. In selecting a legally required standby source of power consideration shall be given as
to type of service and length of time of service and to equipment design to minimize the hazard
that might cause failure due to flood, fires, icing, and vandalism.
Storage batteries shall be capable of maintaining not less than 87 1/2% of system voltage for
not less than 1 1/2 hours. Automatic chargers shall be used and be compatible with batteries
used.
In using a generator set four things need to be followed (1) must have a 15 minute time delay
feature to prevent retransfer for at least 15 minutes (2) internal combustion engines shall have
on-site fuel supply to carry full load for at least 2 hours (3) Prime movers shall not depend
solely on public utility gas for fuel supply or municipal water for cooling. Where two fuel
supplies are used means shall be provided to switch from one to another. (4) Batteries shall be
provided with automatic chargers.
Where the authority having jurisdiction approves, a second service may be allowed as long as
there is a separate service drop or lateral and is widely separated.
Where acceptable to the authority having jurisdiction connection ahead of the main, not in the
main, shall be approved if sufficiently separated from the normal service.
Unit equipment shall consist of (1) rechargeable batteries (2) battery charging means (3)
provisions for one or more lamps and provisions for remote lamps (4) relaying device to
energize lamps upon failure of normal supply.
Branch circuit overcurrent devices shall be accessible to authorized persons only.
APPLICATION:
If time will allow, let the class answer questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 177
LEGALLY REQUIRED STANDBY SYSTEMS
ARTICLE 701
Level II
WORKSHEET
1. Legally required standby power is required to be available within which of the following
from loss of power?
a. 10 seconds
b. 30 seconds
c. 60 seconds
d. 75 seconds
2. A sign shall be placed at the service entrance indicating which of the following
information regarding legally required standby power sources?
a. The size and kind.
b. The location of the transfer switch.
c. Type and location
d. All of the above.
3. Which of the following in legally required standby systems shall be accessible to
authorized persons only?
a. Power panels.
b. Branch circuit overcurrent devices.
c. Start/Stop Switches.
d. Transfer switch keys.
4. Which of the following is not an acceptable power source for required stand by systems?
a. generator set with 1 ½ hour fuel supply
b. storage battery with 1 ½ hour capacity
c. unit equipment with 1 ½ hour capacity
d. connection ahead of service disconnect
5. The legally required standby system wiring shall be permitted to occupy which of the
following
with general wiring?
a. the same raceways
b. the same cabinets
c. the same boxes
d. all of the above
2014 NEC Instructors Manual and Student Worksheets – Level 2 178
LEGALLY REQUIRED STANDBY SYSTEMS
ARTICLE 701
Level II
ANSWER KEY
1. c, 60 seconds 701.12
2. c, type and location 701.7(A)
3. b, branch circuit overcurrent devices 701.25
4. a, generator set with 1 ½ hour fuel supply 701.12(A)
5. d, all of the above 701.10
2014 NEC Instructors Manual and Student Worksheets – Level 2 179
OPTIONAL STANDBY SYSTEMS
ARTICLE 702
Level II
OBJECTIVE:
After completing this lesson, each student should know what an optional standby system is and
the wiring and equipment necessary to provide a safe installation.
INTRODUCTION:
Optional standby systems are intended for private business or property where life safety does
not depend on this system. (See FPN)
PRESENTING THE LESSON:
As in emergency and legally required standby systems all equipment shall be approved for use.
The system shall be sufficient for the capacity of all the equipment to be used at one time.
Transfer equipment shall be approved for use and designed to prevent back feed to normal
power.
Audible and visual signals, where practical, shall be installed to indicate derangement and that
the system is carrying a load.
Signs shall be installed at the service equipment indicating the type and location of optional
standby system.
System wiring shall be permitted to occupy raceways, boxes and cabinets with general wiring.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 180
OPTIONAL STANDBY SYSTEMS
ARTICLE 702
Level II
WORKSHEET
1. Optional standby systems are those systems intended to supply power to public or private
facilities or property where life safety _______ depend on the performance of the system.
a. does
b. does not
c. doesn’t matter
d. can not
2. The optional standby system wiring shall be permitted to occupy the same _______ with
other general wiring.
a. raceways cables
b. boxes
c. cabinets
d. all of the above
3. A sign shall be placed at ______________________________________ indicating the
type and location of on-site optional stand-by equipment.
a. fuel tank
b. service-entrance equipment
c. maintenance shop
d. transfer switch
4. For what 2 purposes shall audible signals be required on optional standby equipment?
I- to warn when the fuel is low
II- To indicate that the optional standby source is carrying load.
a. I only
b. II only
c. both I & II
d. neither I nor II
2014 NEC Instructors Manual and Student Worksheets – Level 2 181
OPTIONAL STANDBY SYSTEMS
ARTICLE 702
Level II
ANSWER KEY
1. (b) does not 702.2
2. (d) all of the above 702.9
3. (b) service-entrance equipment 702.8(A)
4. (b) II only 702.7(2)
2014 NEC Instructors Manual and Student Worksheets – Level 2 182
CRITICAL OPERATIONS POWER SYSTEMS
ARTICLE 708
Level II
OBJECTIVE:
Each student should be familiar with and understand the nature of Article 708 as it relates to
systems necessary for emergency operations of governmental systems.
INTRODUCTION:
Explain the background and reasoning behind instituting guidelines and requirements for
maintaining certain public electrical and utility systems during extreme conditions caused by
loss of services due to weather related or human caused events.
PRESENTING THE LESSON:
Discuss different aspects and concerns based on the Authority Having Jurisdiction and who
that may be to take control and maintain order during catastrophic events where loss of power
and other systems lead to extreme environmental conditions for the inhabitants of the affected
community.
Explain the comparisons between emergency systems covered in Article 700 and how those
requirements there are necessary in addressing similar conditions under Article 708.
Relate the needs for planning by emergency management and proper governmental agencies
responsible for enduring the event and the recovery afterwards to move toward normal
conditions. Express the needs and concerns to understand Article 708
APPLICATION:
Allow the class time to complete worksheet.
CHECKING AND FOLLOW-UP:
Correct the worksheets and discuss the answers with the class.
2014 NEC Instructors Manual and Student Worksheets – Level 2 183
ARTICLE 708
WORKSHEET
LEVEL II
1. Critical Power Operations Systems are those systems classed by:
a. Municipal agency
b. State agency
c. Federal agency
d. Any of the above
2. A Commissioning Plan shall be:
a. developed and documented
b. planned and approved
c. commissioned by the governing agency
d. made up of AHJ’s
3. Hazards to be considered at a minimum shall include:
a. Human caused events
b. Naturally occurring hazards
c. Only a.
d. Both a. & b.
4. Physical security shall be provided based on:
a. Risk assessment
b. Restricted access
c. Only risk assessment
d. Both risk assessment and restricted access
5. Overcurrent devices shall be accessible to:
a. qualified persons
b. only government officials
c. only military personnel
d. authorized persons
6. Alternate power sources shall be capable of operating the COPS for a minimum of:
a. 24 hours
b. 48 hours
c. 72 hours
d. 96 hours
2014 NEC Instructors Manual and Student Worksheets – Level 2 184
ARTICLE 708
LEVEL II
ANSWER KEY
1. d. Any of the above 708.1
2. a. 708.8(A)
3. d. 708.4(B)
4. d. 708.5
5. d. 708.50
6. c. 708.22(C)
2014 NEC Instructors Manual and Student Worksheets – Level 2 185
CIRCUITS AND EQUIPMENT OPERATING AT LESS THAN 50 VOLTS
ARTICLE 720
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with installations operating at less
than 50 volts direct or alternating current.
INTRODUCTION:
This article covers installations operating at less than 50 volts, DC or AC.
PRESENTING THE LESSON:
Cover installations requirements with emphasis on other sections that cover hazardous
locations, overcurrent protection, batteries and grounding. (720.3 & 720.9)
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 186
CIRCUITS AND EQUIPMENT OPERATING AT LESS THAN 50 VOLTS
ARTICLE 720
Level II
WORKSHEET
1. Conductors for appliance branch circuits supplying more than one appliance or appliance
receptacle shall not be smaller than which of the following?
a. No. 8 aluminum or equivalent
b. No. 8 copper or equivalent
c. No. 10 copper or equivalent
d. No. 12 copper or equivalent
2. Standard Lampholders operating at less than 50 volts shall have a rating of not less than
which of the following watts?
a. 100 watts
b. 200 watts
c. 300 watts
d. 660 watts
3. Receptacles for equipment operating at less than 50 volts shall have a rating of not less
than which of the following?
a. 15 amperes.
b. 20 amperes
c. 12 amperes
d. 6 amperes
4. Receptacles of not less than the following rating shall be provided in kitchens, laundries,
and other locations where portable appliances are likely to be used?
a. 15 ampere
b. 20 ampere
c. 30 ampere
d. 40 ampere
2014 NEC Instructors Manual and Student Worksheets – Level 2 187
CIRCUITS AND EQUIPMENT OPERATING AT LESS THAN 50 VOLTS
ARTICLE 720
Level II
ANSWER KEY
1. c, No. 10 copper or equivalent 720.4
2. d, 660 720.5
3. a, 15 720.6
4. b, 20 ampere 720.7
2014 NEC Instructors Manual and Student Worksheets – Level 2 188
CLASS I, CLASS II, and CLASS III REMOTE CONTROL,
SIGNALING AND POWER LIMITED CIRCUITS
ARTICLE 725
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the classification of remote
control, signaling and power limited circuits and the requirements for these circuits.
PRESENTING THE LESSON:
The definition for remote control, signaling and power limited circuits.
Cover the definition of PLTC cable (Power-Limited Tray Cable) 725.2 (new for 2014)
Class 1 remote control and signaling circuits shall not exceed 600 volts, however power output
of the circuit is not required to be limited.
725.3 Locations and other Articles are 300.17, 300.21, 300.22, 500 through 516, and 517, part
IV, Article 392 where installed in cable trays and 430 Part VI and.
Note: 2 new conditions Installation of conductors with other systems and Corrosive, Damp and
Wet Locations
Cover the applicable sections for this new requirement in articles 110.11, 300.5(b), 300.6,
300.9, and 310.10(g)
Wiring methods both supply and load side.
Ampacity per-section 310.15.
Insulation types as listed in 725.49(B). Insulation of conductors larger than 600 volts shall
comply to Article 310.
Number of conductors in cables and raceways.
Section 725.43 gives the requirements for overcurrent protection. Conductors #14 and larger
are to be protected in accordance with Table 310.15. It should be noted because of the
characteristics of these circuits no derating is required. Overcurrent protection shall not exceed
7 amperes for #18 and 10 amperes for #16.
Conductors of Different circuit [725.48] [725.133]
2014 NEC Instructors Manual and Student Worksheets – Level 2 189
Different Class 1 circuits may occupy same enclosure, raceway cable etc. if all conductors are
insulated for the maximum voltage of any conductor present. Power supply and Class 1
conductors shall be permitted in the same enclosure only where functionally associated (see
exceptions).
Conductor [725.49]
A. Ampacities per tables 402.5 and 310.16 through 310.21 as applicable.
B. Insulation types (must be suitable for the system voltage and not less than 600 volts),
review insulation types for #18 and #16 size conductors
Physical protection [725.31(B)]
Where subject to damage conductors must be in conduit or otherwise suitably protected.
C: Class 2 and Class 3 circuits
Power Limitations of Class 2 and Class 3 circuits [725.121]
Power for Class 2 or Class 3 shall be either inherently limited requiring no overcurrent
protection or limited by a combination of power source and overcurrent protection.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 190
CLASS I, CLASS II, and CLASS III REMOTE CONTROL,
SIGNALING AND POWER LIMITED CIRCUITS
ARTICLE 725
Level II
WORKSHEET
1. What is the maximum voltage for a Class 1 power limited circuit?
a. 30 volts
b. 50 volts
c. 75 volts
d. 120 volts
2. What is the maximum power output for Class 1 power limited circuit?
a. 300 VA
b. 600 VA
c. 1000 VA
d. 1200 VA
3. The maximum voltage for a Class 1 remote control circuit is:
a. 120 Volts
b. 250 Volts
c. 300 Volts
d. 600 Volts
4. A Class 2 or 3 power supply shall be which of the following to indicate the class of
supply and electrical rating.
a. A listed Class 2 or Class 3 transformer
b. A listed Class 2 or Class 3 power supply
c. listed equipment marked to identify the Class 2 or 3 power source
d. all of the above
5. For other applications, conductors of Class 2 and Class 3 circuits shall be separated by at
least what distance from conductors of any electric light, power, Class 1 non–power-
limited fire alarm or medium power network-powered broadband communications circuits
unless one of the following conditions is met:
a. 2 in.
b. 6 in
c. 12 in.
d. none of the above
2014 NEC Instructors Manual and Student Worksheets – Level 2 191
CLASS I, CLASS II, and CLASS III REMOTE CONTROL,
SIGNALING AND POWER LIMITED CIRCUITS
ARTICLE 725
Level II
ANSWER KEY
1. a, 30 volts 725.41(A)
2. c, 1000 725.41(A)
3. d, 600 725.41(B)
4. d, all of the above 725.121
5. a, 2 inches 725.136(I)
2014 NEC Instructors Manual and Student Worksheets – Level 2 192
INSTRUMENTATION TRAY CABLE
ARTICLE 727
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with how type ITC cable may be
used.
MATERIALS NEEDED:
Sample of type ITC cable showing markings on sheath.
PRESENTING THE LESSON:
1) Cover the uses permitted in section 727.4 and uses not permitted in section 727.5
2) Cover construction, sizes, and ampacities of ITC.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 193
INSTRUMENTATION TRAY CABLE
ARTICLE 727
Level II
WORKSHEET
1. The insulated conductors of type ITC Cable shall be in sizes:
a. No. 14 through 16
b. No. 8 through 10
c. No. 22 through 12
d. No. 2 through 6
2. The ampacity of the conductors of instrumentation tray cable shall be:
a. 5 amperes except 22 AWG shall be 3 amperes
b. 10 amperes except 22 AWG shall be 5 amperes
c. 15 amperes except 22 AWG shall be 8 amperes
d. 9 amperes except 22 AWG shall be 6 amperes
2014 NEC Instructors Manual and Student Worksheets – Level 2 194
INSTRUMENTATION TRAY CABLE
ARTICLE 727
Level II
ANSWER KEY
1. c, No. 22 through 12 727.6
2. a, 5 amperes except 22 AWG shall be 3 amperes 727.8
2014 NEC Instructors Manual and Student Worksheets – Level 2 195
FIRE PROTECTIVE SIGNALING SYSTEMS
ARTICLE 760
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the installation of wiring
systems and equipment of fire protective signaling systems operating at 600 volts, nominal, or
less.
INTRODUCTION:
Fire protective systems are one of the most important components of an electrical system.
Because of the danger to life and property and the liability involved, it is essential that the
system work as expected.
PRESENTING THE LESSON:
Article 760 of the NEC addresses the requirements and wiring methods to be used when
installing fire protective systems. Other articles which apply include: 300.21, 300.22, 500-
through 516 for and 517 Part IV. The building code also determines system requirements so
coordination with building inspection department is necessary.
Fire Protective circuits are classified as either non-power limited or power limited [760.2]. All
circuits must comply with Part A. Parts B and C apply to non-power limited and power limited
circuits respectively.
Part B-Nonpower limited FPSC: Discuss thoroughly.
Conductors of Class 1 and NPLFA circuits that occupy the same raceway must be insulated for
the maximum voltage present. See 760.48(A)
Conductors shall be solid or stranded copper and comply with provisions of 760.49(C).
Multiconductor cable must be listed for fire alarm use. The number of conductors in raceway is
determined by 760.51.
Part III-Power-Limited (PLFA) Circuits: Circuits must be clearly marked at terminations as a
power limited fire alarm circuit.
Wiring on supply side of overcurrent protection, transformers etc. must be installed in
accordance with Part II of 760 and Chapter 3 wiring methods.
Power limited circuit conductors must be installed according to 760.133. Signaling circuits
installed as wiring within buildings must be listed for resistance to fire spread. Cover 760.133.
2014 NEC Instructors Manual and Student Worksheets – Level 2 196
Power limited circuits must meet the requirements of 760.136 for separation from light, power,
Class 1 and non-power limited fire protective circuits. Go over exceptions. (760.130)
Cover conditions under which Class 2 circuits can be permitted within same raceway with
power limited fire protective signaling circuits. (760.139)
Conductors and cables must be listed for fire protective system use and meet or exceed the
requirements of 760.53. Listed cable must be marked to comply with 760.161 and 760.176G.
Show overhead of Table 760.176(G).
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 197
FIRE PROTECTIVE SIGNALING SYSTEMS
ARTICLE 760
Level II
WORKSHEET
1. Fire alarm circuits shall be identified at which of the following locations in a manner that
will prevent unintentional interference with the signaling circuit during testing and servicing?
a. Terminal and junction locations.
b. Pull stations and terminal junctions.
c. Terminals and cardholders.
d. Cardholders and Pull stations.
2. When extending beyond one building power-limited fire alarm circuits shall meet
installation requirements of which of the following?
I. Parts II, III, and IV of Article 800
II. Part I of Article 300
a. I only
b. II only
c. Neither I or II
d. Both I and II
3. Overcurrent protection shall not exceed which of the following for #18 conductors?
a. 10 amperes
b. 7 amperes
c. 6 amperes
d. 5 amperes
4. NPLFA conductor materials shall be of which of the following?
I. Solid copper.
II. Stranded copper.
a. I only
b. II only
c. Neither I or II
d. Either I or II
2014 NEC Instructors Manual and Student Worksheets – Level 2 198
5. Where located within 7 feet of the floor, NPLFA cable shall be securely fastened at
which of the following intervals?
a. 1 ½ feet
b. 2 feet
c. 4 feet
d. 3 ft. 6 inches
6. Type FPL cables installed as wiring within buildings shall be listed as which of the
following?
I. Listed as being resistant to the spread of fire.
II. Listed for circuit integrity and marked with the suffix CI
a. I only
b. II only
c. Neither I nor II
d. Both I and II
7. Which of the following types of power limited fire alarm plenum cable shall be listed for
use in ducts or plenums and other air-handling spaces?
a. BFPLP
b. FPLP
c. PLPF
d. PPLF
8. Power-limited circuits shall be separated from Class I circuits by which of the following
distances?
a. 12 inches
b. 6 inches
c. 4 inches
d. 2 inches
2014 NEC Instructors Manual and Student Worksheets – Level 2 199
FIRE PROTECTIVE SIGNALING SYSTEMS
ARTICLE 760
Level II
ANSWER KEY
1. a, terminal and junction locations 760.30
2. d, Parts II, III, and IV of Article 800 and Part I Article 300 760.32
3. b, 7 amp 760.43
4. d, either I or II 760.49 (C)
5. a, 1 ½ feet 760.53(A)(1)
6. a, I only 760.179(F)
7. b, FPLP 760.179(D)
8. d, 2 inches 760.136(G)
2014 NEC Instructors Manual and Student Worksheets – Level 2 200
OPTICAL FIBER CABLES AND RACEWAYS
ARTICLE 770
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with optical fiber cables and it’s
permitted use and types.
MATERIALS NEEDED:
Samples or pictures of cable.
INTRODUCTION:
Explain to student that this is a short article, and it will be covered very briefly. It is not very
often encountered in the field at the present time but this will be more common in the future.
PRESENTING THE LESSON:
Show samples or pictures of cables. Cover types of optical fiber cables [770.5] and other
articles that apply to their installation. [770.3]
Emphasize the requirement for wiring within building and the fire resistant rating of cables and
cable marking. [770 Part III]
Cover the requirement of installing optical fiber and electrical conductors in the same raceway.
[770.6]
Discuss mechanical execution of work. [770.8]
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 201
OPTICAL FIBER CABLES
ARTICLE 770
Level II
WORKSHEET
1. Which of the following is correct concerning the installation of conductive optical fiber
cables?
I. Optical fibers shall be permitted in the same raceway with class 2 and class 3 remote
control signaling and power-limited circuits.
II. Nonconductive optical fiber cables shall not occupy the same outlet box housing as the
class 1 circuit. (without exception)
a. I only
b. II only
c. Both I and II
d. Neither I nor II
2. Optical fiber cables installed as wiring for general use within buildings shall be which of
the following?
I. Shall be OFC type.
II. Shall be OFN type.
a. I only
b. II only
c. Both I and II
d. Neither I nor II
2014 NEC Instructors Manual and Student Worksheets – Level 2 202
OPTICAL FIBER CABLES
ARTICLE 770
Level II
ANSWER KEY
1. c, Both I and II 770.133(A) and (B)
2. c, Both I and II 770.179(D)
2014 NEC Instructors Manual and Student Worksheets – Level 2 203
COMMUNICATION CIRCUITS
ARTICLE 800
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar with the requirement for
communication circuits.
INTRODUCTION:
This Article covers the requirement for telephone, telegraph, district messenger, outside wiring
for fire alarm and burglar alarms.
PRESENTING THE LESSON:
Part II covers the requirement for outside conductors. Go over 800.44 as to the requirement for
overhead conductors -- on poles, on buildings, and entering buildings.
Part II also covers Underground Circuits entering buildings. Cover the requirements,
800.47(A), for separation of communication circuit from light and power conductor in
handholes, manholes, etc.
Part III covers the requirements for protective devices. Emphasis should be placed on the type
and location of the protector as covered in 800.90.
Part IV covers Grounding of communication circuits. Special emphasis should be placed on.
This covers the cable sheath and protection ground with requirement for insulation, size and
installations of the grounding conductor. Emphasis should be placed on the electrode and
electrode connection.
Part V places special emphasis on the installation of conductors is necessary to make sure the
student is familiar with these requirements. Cover the requirements concerning the separations
from other conductors. The requirement for fire resistance of wires and cables installed as
wiring within buildings should be emphasized. (OL Table 800.113) Note the requirement for
listing of the conductors.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 204
COMMUNICATION CIRCUITS
ARTICLE 800
Level II
WORKSHEET
1. The primary protector shall be located in which of the following places?
I. On, or immediately adjacent to the structure or building served.
II. As close as practicable to the point of entrance.
a. I only
b. II only
c. Neither I or II
d. Both I and II
2. Communication conductors run in the same shaft with light and power conductors shall
be separated by which of the following?
a. 2 inches
b. 6 inches
c. 2 feet
d. 30 inches
3. Communication cables installed in plenums shall be listed and marked in which of the
following manners?
a. CM
b. CMP
c. CMR
d. CMX
4. The communication grounding electrode conductor shall be which of the following?
I Insulated (Covered or Bare)
II. Listed
a. I only
b. II only
c. Neither I nor II
d. Both I and II
2014 NEC Instructors Manual and Student Worksheets – Level 2 205
COMMUNICATION CIRCUITS
ARTICLE 800
Level II
ANSWER KEY
1. d, Both I and II 800.90(B)
2. a, 2 inches 800.133(A)(2)
3. b, CMP 800.154(A)
4. d, both I and II 800.100(A)(1)
2014 NEC Instructors Manual and Student Worksheets – Level 2 206
RADIO AND TELEVISION EQUIPMENT
ARTICLE 810
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar the requirements of radio and
television receiving equipment and amateur transmitting and receiving equipment.
MATERIALS NEEDED:
Slides or transparencies of connections of grounding conductor to electrode.
INTRODUCTION:
This Article covers the requirement of antenna systems for radio and TV receiving equipment,
amateur transmitting and receiving antenna system and interior transmitter station installations.
PRESENTING THE LESSON:
Refer to the other Articles that pertain to the general wiring methods for power to these
systems. Sound recording (640) and optical fiber cables (770) shall comply with their
applicable Articles. The distribution system for CATV is not covered in Article 810 but
covered in Article 820.
810-Part II (810.11 through 810.21) This part covers antenna systems for receiving equipment.
Areas that should be emphasized are materials, supports, proximity of conductor to other
system, and splicing. Other areas of emphasis should be size of lead-in conductor and
clearances on the outside and inside of buildings.
Special emphasis should be given to section 810.15 and 810.20 and 810.21. These sections
cover the requirements for grounding masts and metal structures supporting antennas and
antenna discharge units.
Section 810.21 covers the requirements for grounding conductors. Be sure to go over the
requirements covered in Sections 810.21 (F)(1)(2)(3), 810.21(G)(H)(I)(J) & (K) as it relates to
the overall grounding requirements for radio and television equipment.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 207
RADIO AND TELEVISION EQUIPMENT
ARTICLE 810
Level II
WORKSHEET
1. This article covers antenna systems for radio and television receiving equipment, amateur
and citizen band radio transmitting and receiving equipment, and certain features of transmitter
safety. This article also covers all of the following except?
a. Antennas such as multi-element.
b. Vertical rod, and dish antenna.
c. The wiring and cabling that connects them to equipment.
d. Antennas used for coupling carrier current to power electronics
2. What is the maximum distance between supports for medium or soft drawn copper when
used with antenna systems?
a. Less than 50 feet
b. Less than 25 feet
c. Less than 35 feet
d. Less than 10 feet
3. Outdoor antenna and lead-in conductors when in proximity of power conductors of less
than 250 volts between conductors shall maintain a clearance of which of the following?
a. 2 inches
b. 2 feet
c. 6 inches
d. 6 feet
4. What size hard drawn copper would be required for a one hundred (100') foot span for
Receiving Station outdoor antenna conductors?
a. 12
b. 14
c. 19
d. 20
5. The minimum size grounding conductor shall not be smaller than which of the following?
a. 10 copper
b. 8 copper
c. 17 copper
d. 6 copper
2014 NEC Instructors Manual and Student Worksheets – Level 2 208
RADIO AND TELEVISION EQUIPMENT
ARTICLE 810
Level II
ANSWER KEY
1. d, antennas used for coupling carrier current 810.1
2. c, less than 35 feet 810.11 ex.
3. b, 2 feet 810.13
4. b, 14 Table 810.16 (A)
5. a, 10 810.21(H)
2014 NEC Instructors Manual and Student Worksheets – Level 2 209
COMMUNITY ANTENNA TELEVISION AND
RADIO DISTRIBUTION SYSTEMS
ARTICLE 820
Level II
OBJECTIVE:
After completing this lesson, each student should be familiar the requirements for radio and
CATV distribution systems.
MATERIALS NEEDED:
Samples of listed cables.
Slides or transparencies of connection of grounding conductor to electrode.
INTRODUCTION:
This Article covers the requirement for protection, installation and grounding of cables for
CATV and radio distribution systems.
PRESENTING THE LESSON:
This Article covers the cable distribution system for CATV and Radio. Part I covers the
energy limitation, material, and requirement for marking the cable. Emphasis should be placed
on the requirement for listing and special marking on the cable as required in Section 820.179
and Table 820.179.
Part II covers the requirements for lighting and power surge protection for cable entering the
building. Emphasis should be placed on the proper application of protective devices.
Part III covers the protection of cables. Cover 820.44 , outside conductor, with emphasis on
(F) (1), (2) and (3) covering separations of cables from conductor of other systems. Cover
Section 820.133, inside conductors, with emphasis on part (A) -- separation of cables and light
and power conductors; installations of cable in raceway, boxes etc.; and installation of cable
with other conductor when installed in accordance with their respective Article.
Special emphasis should be placed on Section 820.3(A). These sections cover requirements for
the prevention of spread of fire and products of combustion. Note the requirements for fire
rating of coaxial cable installed within building, vertical shafts and ducts, plenums and other
air handling spaces.
2014 NEC Instructors Manual and Student Worksheets – Level 2 210
Part IV covers the requirement for grounding the coaxial cables. Special emphasis should be
placed on Section 820.100. This covers grounding requirement-material, size etc. and the
requirement for electrode and electrode connection.
APPLICATION:
If time will allow, let the class answer the questions on the worksheet.
CHECKING AND FOLLOW-UP:
If time will allow, correct the worksheets and discuss the results.
2014 NEC Instructors Manual and Student Worksheets – Level 2 211
COMMUNITY ANTENNA TELEVISION AND
RADIO DISTRIBUTION SYSTEMS
ARTICLE 820
Level II
WORKSHEET
1. Coaxial Cable shall be permitted to deliver low-energy power to equipment associated
with the radio frequency distribution system if the voltage is not over which of the following?
a. 60 volts
b. 100 volts
c. 120 volts
d. 250 volts
2. Listed CATV cables used in a plenum shall be marked as which of the following?
a. CATV
b. CATVD
c. CATVP
d. CATVR
3. CATV and lightning conductors should be spaced at least what distance apart?
a. 2 feet
b. 4 feet
c. 6 feet
d. 10 feet
4. The minimum size grounding conductor shall not be smaller than which of the following
for CATV systems?
a. 16
b. 14
c. 12
d. 6
2014 NEC Instructors Manual and Student Worksheets – Level 2 212
COMMUNITY ANTENNA TELEVISION AND
RADIO DISTRIBUTION SYSTEMS
ARTICLE 820
Level II
ANSWER KEY
1. a, 60 820.15
2. c, CATVP 820.154(A)
3. c, 6 feet 820.44(E)(3)
4. b, 14 820.100(A)(3)