Electrical Specifications for Conduit Raceways

Wire Size

• Wire size is measured by its gauge, which is the diameter of the metal conductor and determines the number of amps the wire can handle. Common wire gauges in residential applications are 14 gauge wire used for outlets and lights, 12 gauge wire used for kitchen outlets and baseboard heaters, and 10 gauge wire used for water heaters. Wire gauge counter-intuitively gets smaller as the wire diameter gets larger.

Wire Number

• The number of wires is the physical number of metal conductors. A typical 120 volt circuit uses three equal gauge wires to complete the electrical transmission. A hot wire delivers the power, the neutral wire provides the path back to the source and the ground connection is the back up safety wire. A 240 volt circuit uses four conductors to complete the circuit. This is the same as a 120 volt connection except it is has two hot connections instead of one.

Conduit Specifications

• The size of the conduit is the inside diameter of the pipe. Choosing a conduit size is determined by the gauge of the wires inside of it and the number of conductors. It is always wise to use one conduit size larger then you need to facilitate expansion of the electrical system in the future.

Conduit Material

• Conduit is made from several difference materials. Rigid steel conduit is typically used in applications where the odds of mechanical damage are high. EMT conduit is a thin walled metal pipe that is easily bent and can be used for exterior use. PVC conduit is made for below-ground or exterior use because it can be installed water tight.. Flexible metal conduit looks similar to armored cable and is easily bent with your hands. It is typically used when movement of the conduit is expected.