How to Install Electrical Conduit?

Conduit is metal or plastic tubing used to create a protective channel for electrical wire. The channel, along with electrical boxes and devices that join the conduit pieces, is known collectively as raceway.

In a household wiring system, most of the circuit wiring is in the form of insulated cable that is run inside wall, floor and ceiling structures without conduit. Conduit typically is used only where circuit wires are exposed (or surface-mounted or buried) and therefore need protection from damage or moisture.

Conduit Installation

Conduit usually contains two or more individual insulated wires. This marks another distinction from cable, which consists of multiple wires encased in a protective jacket or armor. Cable typically is not run through conduit.

In a standard installation, an entire raceway—including the conduit, boxes, connectors and fittings—is installed before the individual wires are threaded through the raceway. Electricians call the wiring phase "pulling" or "fishing" because the wires are pulled through the raceway with a flexible metal ribbon called a fish tape.

Each type of conduit has its own fittings (which connect lengths of conduit together) and connectors (which join conduit to boxes). Fittings include straight couplings and various elbows and tees, much like plumbing fittings, for extending or changing the direction of the conduit run. Some fittings have removable plates or covers that provide access to the conduit interior to facilitate pulling the wires; when installed, these are often referred to as "pull points."