Is it necessary to run a ground wire inside emt?

Answer 1

In the United States, the NEC (the code) allows emt to be used as your grounding conductor. But there are some requirements that make it impractical.

First, the fittings (couplings and connectors) must be listed for grounding purposes. As an electrician, I know that properly installed emt provides adequate grounding, but the code requires the fittings to be LISTED for the purpose, and I have never seen an UL listing stating this to be so.

You are also required to BOND boxes and devices such as receptacles and switches to the grounding conductor. Bonding the boxes cannot be done without properly listed connectors. Bonding devices can easily be done if you buy the right parts because some are manufactured for and listed as self-bonding.

What I am saying is this: Technically it is not necessary to run a ground wire inside emt. But other requirements of the code cannot be satisfied.

I would never do it on my own, but I might with clearance from my supervision and/or the inspecting jurisdiction. I was on a $300M government job that was designed, in its entirety, for the conduit to be used as grounding conductors. But as much as we discussed it and tried to make that happen, we couldn't satisfy the code.

Answer 2

In an EMT (Electrical Metalic Tubing) system the conduit system serves as the ground return. In some instances a ground wire also has to be installed in the conduit system along with the load wires.

Answer 3

Yes it should be grounded