My Library

The amperage of the electrical service and the number of circuits and outlets installed should take future needs into account. Modern house services usually require 200 amps. Wiring is usually started after the house has been enclosed. The initial phase of wiring is called roughing-in and includes the installation of wiring and the boxes for the switches, lights and outlets. Figure 160 shows some typical electrical equipment. Roughing-in is done before the inside finish is applied and usually before insulation is placed in walls and ceilings. Lighting fixtures, switches, outlets and cover plates are installed after the interior finish and painting operations are complete.
Location of Switches and Outlets Plan the location of switches and outlets carefully. Electrical boxes located in insulated ceilings and exterior walls must be sealed to prevent air leakage. Solid plastic airtight electrical boxes are recommended for use in exterior walls and ceilings. Switches are typically located just inside a door opening so that they may be easily reached when the door is opened. Switches may activate a wall outlet for a table or a floor lamp or ceiling or wall lights. Locate switches about 1.4 m (4 ft. 6 in.) above the floor, or 1.2 m (4 ft.) above the floor for a person in a wheelchair (see About Your House fact sheet Accessible
160 Typical electrical equipment
Octagonal boxes for use with fixture or junction outlets
Use approved boxes for switches and outlets in the house
Duplex wall outlet and plate
Toggle switch and plate
Circuit breaker