Steel conduit has been in use as a “raceway system” for electrical conductors since the early 1900s. The wall thickness and strength of steel make metal conduit the wiring method recognized as providing the most mechanical protection to the enclosed conductors. An additional benefit of using steel conduit is that the NEC recognizes a properly installed metal conduit system as an equipment grounding conductor.
Three basic types of steel conduit are in use today: rigid metal conduit, intermediate metal conduit, and electrical metallic tubing. Let's take a closer look at the features of each type.
Applications. There are two primary reasons to use steel conduit. It's the best possible protection of your electrical conductor and wiring systems, and it facilitates the insertion and extraction for conductors and wiring. Today, steel conduit is used in virtually every application where electrical conduit and wiring is present: commercial, retail and residential buildings, manufacturing and other industrial facilities, health-care, educational and other institutions, and a wide variety of indoor, outdoor, and underground applications, even where corrosive and hazardous conditions exist.
