How to Install Galvanized Rigid Conduits

Learn how to install galvanized rigid conduits efficiently and effectively. Electrical conduit protects and routes electrical wiring. It can be made of many materials, including metal, plastic, fiber, or fired clay. Flexible and rigid conduit are available. The type of conduit used is determined by wiring regulations set forth by national and local codes. It is important to know how to install galvanized conduit properly.  GRC, or galvanized rigid conduit, is simply galvanized steel tubing. The wall of the tubing is thick enough to allow it to be threaded, and therefore, is commonly found in industrial applications. The conduit comes in various sizes. Use available charts to determine the correct size for your application. The guidelines will determine the fill factor, which is the maximum amount of space that the conductors running through the conduit can occupy. The amount of wires you are running will determine the size of conduit needed. Choosing to use galvanized rigid conduits is advantageous over PVC conduits because they may also serve as the grounding path. However, some local codes may require that you also run a green grounding wire.

Step 1 – Anchor Metal Box

The first thing that you need to do is to anchor your metal boxes to the wall with the screws provided. Choose a box with an offset filling if you can. This will allow the conduit to run tightly against the wall.

Step 2 – Measure the Conduit Length

You can use a tape measure to measure the distance for the conduit . However, a better method, if you are going in a straight line, is to simply hold the piece of conduit in place and mark right on the conduit. Be sure to add an additional inch to each side to allow it to slide into the box. For applications with a bend, you may need to use the tape measure.

Step 3 – Cut the Conduit

Use a hacksaw, not a tube cutter, to cut the conduit.  Shave off any burrs on the inside and the outside of the conduit with a conduit-reaming attachment to a screwdriver. Do not skip this step as you may damage the conductors as you pull them through.

If you are have to put a bend in the conduit, it is far simpler to use a pre-bent conduit than using a conduit bender and bending it yourself. Use a coupling to connect the pieces of conduit.

Step 4 – Set the Conduit in a Box

Slide the conduit ends into the fittings on the boxes and tighten the screws securely. These connections are critical if you are not installing a green grounding wire and therefore, it is imperative that these connections are tight.

Step 5 –Anchor the Conduit

Use a one or two hole strap, distanced at least every six feet as well as within two feet of the boxes. Be sure to drive the screws into the joists or studs.