CHAPTER 14 Boxes and Wiring Devices

A box is used in electrical wiring—at each junction point, outlet, and switch. Boxes provide access to electric connections and serve as a mounting for fixtures, receptacles, and switches. They may also be used as pull points for wire in long runs. A wiring device is a switch or receptacle that controls, but does not consume, electricity. This chapter has five sections that cover various types of boxes, cabinets, wiring devices, and the appropriate fasteners and hangers to secure each. Descriptions, units of measure, material and labor requirements, and a takeoff procedure are suggested for each.


Pull boxes are inserted in a long run of conduit to facilitate the pulling of wire. They are also used where conduit changes direction or wires divide into different directions. Cabinets are used where wire terminates. Both come in various National Electrical Manufacturer's Association (NEMA) types to match the requirements of a specific application or environment.

Boxes and cabinets are usually made of galvanized steel, epoxy-painted steel, stainless steel, aluminum, or high-density plastic and frequently include covers. Less common materials include malleable iron, cast iron, and cast aluminum.

Units of Measure. Boxes and cabinets are taken off and quantified individually as each (EA). They are tabulated by size (dimensions), type (composition), and even by application (interior or exterior).

Material Units. The following ...

Get Electrical Estimating Methods, 4th Edition now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.