EET 110 - Survey of ElectronicsChapter 24 - Residential Branch

Circuit Wiring

NEC Branch circuit requirements

all parts of a circuit that lie beyond the overcurrent device up to the last outlet.

A max of 12 outlets per branch practical limit 8 - 10

A separate duplex must be installed in laundry or utility area.

A duplex at least every 6 feet

NEC Branch circuit requirements

A duplex with GFI protection must be installed at counter height in bathroom/washroom

outdoor at least one one GFI circuit

garage at least one duplex

NEC Branch circuit requirements

Kitchen at least 2 - 20A circuits for appliances. No point on counter more than 24 inches from

outlet split receptacle outlet - 2 hot circuits 50 A, 120V/240V for range

NEC Branch circuit requirements

Color code neutral wire White or neutral gray hot wire black or red ground wire bare or green

pull-chain lamp with duplex receptacle

from a single fuse connection to device to neutral bus

pull-chain lamp with duplex receptacle

switch with lampholder

switch with lampholder

two lamps with a single switch

lamps run in parallel all devices for household wiring are built for

120 volt

Wiring Diagrams

Note that the wiring diagram illustrates the connections that should be made

It differs from the schematic for the same circuit

SThe wiring diagram for two lights in series w/ switch

The schematic for this circuit

Shows the lamps in parallel.

Layout plan

Planning the electrical system requires laying out the physical devices in the floor plan.

Electrical connection to meet NEC rules and to identify switched circuits follows.

Wiring

wiring is in parallelnote each combination of wiring circuittypical layout plantypical wiring diagram

box placement

switch boxes from 44 to 48 inches from floor (bottom of box)

receptacle boxes from 12 to 18 inches from floor.

maximum number of wires allowed in boxes depend on size and number see table 24-2

Assignment

Review questions 1-15 page 333Read Chapter 26, 27, 29