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NEC 358.60 Grounding:

EMT shall be permitted as an equipment grounding conductor.

I have some old EMT from an era before grounding was common. I need a grounding connection at one end of it and there is no other good ground to use (all nearby circuits come from a different panel, I could probably connect to the grounding electrode wire near the water main though). I am wondering if I can use this conduit as a grounding conductor by replacing a box on each end to have a proper ground screw attachment (the conduit does not go all the way back to the panel, but rather is connected to the panel by Romex). My concern is that old conduit may not be listed as a ground conductor, but the NEC 358.60 article says nothing about listing (while other articles, such as 320.6 say that listing is required).

volcanosandwich
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2 Answers2

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  1. If the person installing it didn't know it would be used as a ground path in a manner that had not yet been defined and standardized, you should not rely on it doing so. You should inspect every inch of it and every connection. At that point, it's "installed by" you.

  2. Wait. A conduit you say? Why not pull a ground wire through it? Some electricians would pull one no matter what, out of some weird religious opposition to using conduits that way. But here .... why not?

jay613
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Let's back up and ask a key question here: Is anything bonded to a grounding electrode?

Older electrical panels were not required to have one, and you might not have a properly bonded system overall. The EMT bonding would merely be a secondary concern.

the conduit does not go all the way back to the panel, but rather is connected to the panel by Romex

The EMT would have to be bonded to a grounding electrode somewhere to be considered bonded. That's why modern EMT is considered a grounding path. By itself, this partial conduit is not bonded.

I have not heard of any particular metal being excluded from being considered a valid ground path.

Machavity
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