Custom Search
|
|
 
|
||
|
The NEC requires
that outlet boxes be 1 1/2 in. deep
except when the use of a box of this depth will result
in injury to the building structure or is impractical,
in which case a box not less than 1/2 in. deep
may be used. For switch boxes, the 2 1/2-in. depth is
the most widely used. The NEC
also requires that the outside
Figure 9-17.-Types of outlet boxes. edges of outlet and switch boxes without flush plates NOT be recessed more than 1/4 in. below the surface of the finished wall.Receptacles RECEPTACLES are used to plug in lights and appliances around the building. Some of the types of receptacle commonly used in interior wiring are discussed in the following paragraphs in the order of their frequency of use.A CONVENIENCE OUTLET (fig. 9-18) is a duplex receptacle with two vertical or T-slots and a round contact for the ground. This ground is connected to the frame of the receptacle and is grounded to the box by way of screws that secure the receptacle to the box.A RANGE RECEPTACLE (fig. 9-19) maybe either a surface type or a flush type. It has two slanted contacts and one vertical contact and is rated at 50 A. Receptacles for clothes dryers are similar but are rated at 30 A. Range and dryer receptacles are rated at 250 V and are used with three-wire, 115/230 V, two hot wires and a neutral. A receptacle for use with an air-conditioner taking 230 V is made with two horizontal slots and one round contact for the ground.Also used in the Navy are strips that allow movement of the receptacle to any desired location. These strips are available in 3-ft and 6-ft lengths and may even be used around the entire room. This type of outlet is particularly desirable in rooms where portable equipment or fixtures,
Figure 9-18.-A typical duplex convenience outlet.
Figure 9-19.-Range receptacle. such as drafting tables and audio-visual equipments, are used. Specialty outlets (weather-proof are used in all exterior locations because they resist weather damage. |
 
|
|
|
||
