29 Electrical Plans Chapter Permission granted to reproduce for educational use only.©...

29Electrical Plans

Chapter

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.

Objectives• Describe an electrical plan and identify its

features.• Identify typical electrical symbols found on a

residential electrical plan.• Draw an electrical plan for a residential structure

using manual drafting techniques.• Draw an electrical plan for a residential structure

using CADD.


Electrical Plan

• Electrical plan shows location and type of electrical equipment to be used– Plan view section– Usually traced from floor plan– Shows meter distribution panel, outlets, switches,

and special features– Identifies number and types of circuits


Required Information

• Service entrance capacity• Meter, distribution panel location• Location, placement, type of switches• Location, type of lighting fixtures • Special electrical equipment

• Number, type of circuits


Required Information

• Electrical fixture schedule• Symbols, legends, and notes• Required amperage rating of service is shown

beside distribution panel


Common Electrical Symbols


Service Entrance

• Locate service entrance equipment close to service drop

• Main breaker should be close to meter• Locate service entrance close to largest energy

users• Larger loads require larger conductors• Shorter runs reduce voltage drops


Employability

• Negotiation– Process of coming to agreement on an issue that

requires all parties to give and take a little to achieve intended result

– Begins with trying to understand the other person’s interests

– Together try to reach possible solutions that meet mutual concerns


Meters

• Outside location is preferred, but meter can be located inside or outside

• Smart meters can be read remotely by utility company


Switches

• Number and placement of switches is related to number of lighting fixtures, switched outlets, and equipment

• Select logical location for each switch• Use proper symbols to show type of switch


Switches

• On electrical plan, switches are shown connected to fixtures, appliances, and outlets they operate

• Thin, curved hidden line or centerline shows connection– Lines do not represent actual wiring, but only

elements connected

• Use SPLINE or POLYLINE in CADD


Receptacle Outlets

• Place outlets every 6' to 8' along all walls• Outlets are usually 120-volt duplex• Some duplex outlets may be split-wired• Receptacle outlets should be grounded or GFCI to

prevent shock


Receptacle Outlets

• Receptacle outlets may be switched or always “hot”

• Consider furniture arrangement when locating switches and outlets


Special-Purpose Outlets

• Special-purpose receptacle outlets may have one or several receptacles

• Unique symbols should be identified in a legend


Traditional Lighting

• Two types of lights have been commonly used• Incandescent light

– Screw-in bulb

• Fluorescent light– Tube


Energy-Efficient Alternatives

• Compact fluorescent lightbulbs (CFLs)– Contain mercury

• Light-emitting diode (LED) lights– Multiple colors; many uses

• Electronic-stimulated luminescence (ESL) lights– Up to 70% more energy-efficient than incandescent

bulbs


Lighting Fixtures

• Trend is toward more freestanding lamps and fewer ceiling-mounted fixtures

• Recessed lighting fixtures for hallways, foyers, or special emphasis

• Track lighting is another option


Exterior Lighting

• Exterior light fixtures should be rated for exterior applications

• Plan adequate lighting for:– Walks– Drives– Porches– Patios– Other outside areas


Lighting Fixture Schedule

• Use proper symbol for each lighting fixture at actual location

• Include lighting fixture schedule in electrical plan


Architecture

• Phasing out the incandescent lightbulb– In United States, higher-energy bulbs were

restricted first, with phase-out to be completed in 2014

– Some bulbs are exempt from restrictions, such as appliance lamps

– Keep up-to-date with new technologies and incorporate them into designs when possible

Green


Other Devices

• Telephone jacks• Intercom system• Home security devices• TV antenna jack• Cable or satellite TV jack• Door chimes• Audio outlets


Branch Circuits

• Electrical plan indicates number and type of branch circuits

• Circuit data is generally shown as note, chart, or diagram on electrical plan

• Number of lighting, small-appliance, and individual circuits should be listed


Manual Drafting: Electrical Plan

1. Trace exterior and interior walls and major appliances from floor plan.

2. Locate meter and distribution panel. Indicate voltage and amperage rating. Locate telephone junction box and home security or automation wiring enclosure. Check building code requirements.



3. Show all receptacle outlets using proper symbols.

4. Locate all ceiling and wall lighting outlets. Use standard lighting symbols.

5. Show all special-purpose outlets and fixtures.

6. Locate switches and connect them to outlets and lighting fixtures they operate.



7. Add lighting fixture schedule and symbol legend, if needed.

8. Note number and type of circuits required.

9. Letter all other notes and title, scale, and sheet number.

10. Check drawing for accuracy and completeness.


Residential Electrical Plan


CADD: Electrical Plan

1. If electrical plan is to be a separate file, open floor plan drawing and save it with new name. If combining electrical plan with floor plan, create set of layers specifically for electrical plan and lock or freeze all other layers.



2. Locate meter and distribution panel. Indicate voltage and amperage rating. Locate telephone junction box and home security or automation wiring enclosure. Double-check local building codes.

3. Insert symbols for receptacle outlets, placing them on electrical symbols layer. Indicate receptacle types.



4. Insert symbols for ceiling and wall lighting outlets on electrical symbols layer.

5. Insert symbols for special-purpose outlets and fixtures on the electrical symbols layer.

6. Insert symbols for switches on electrical symbols layer.



7. Connect switches to outlets and lighting fixtures they operate. Use hidden or centerline linetype with SPLINE command or Spline option of POLYLINE command. Place these lines on separate layer to achieve proper line width when plotting.

8. Add lighting fixture schedule and symbol legend, if needed.


CADD Drafting Procedure

9. Add note indicating number and type of required circuits. Create other notes and add title, scale, and sheet number. Place specific notes on their own layer.

10. Check drawing for accuracy and completeness.


Residential Electrical Plan Drawn Using CADD

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