EGC insulation

[ggunn]

It makes sense to me that if you have an EGC run with 2000V wiring in a conduit the EGC shouldn't have to have 2000V insulation, since if the conduit is metallic it must be grounded, and it isn't insulated at all. Agree?

 

[ron]

Agreed. The EGC can be 600V insulation, or even no insulation.

 

[electrofelon]

This issue has come up before and I'm with Ron. The solar firm we have done some large installations used 2kv rated EGC. I asked the engineer, and he just had some vague answer like "we've been told it should match the conductor rating." The manufacturers clearly make it, not sure why.

 

[big john]

Only time I've seen EGC insulation matter is if the system is not solidly grounded, or a very long conductor is only grounded on one end: In either case there's the possibility for a fault to impose significant voltage on the EGC.

Assuming this is a normal equipment grounding system, I see no reason for the EGC to have 2kV insulation.

 

[Carultch]

Only time I've seen EGC insulation matter is if the system is not solidly grounded, or a very long conductor is only grounded on one end: In either case there's the possibility for a fault to impose significant voltage on the EGC.

Assuming this is a normal equipment grounding system, I see no reason for the EGC to have 2kV insulation.

I'm not aware of a single instance, where a bare EGC is not code compliant. On such a situation as you describe, where it is plausible for a fault to impose that kind of voltage on the EGC, what would happen if one were to install a code-compliant bare EGC?

There are practical reasons to insulate your EGC, such as avoiding dissimilar metal corrosion, and minimizing abrasion during pulling. Few (if any) have anything to do with the need to actually insulate it against a voltage difference. The purpose of EGC insulation is more often mechanical or chemical, rather than electrical. The entire allowance for a bare EGC indicates that logically an EGC should be able to have any voltage rating.

 

[big john]

I'm not aware of a single instance, where a bare EGC is not code compliant....

I was incorrectly thinking of the neutral in an HRG system for my other example, though. That would have to be fully insulated, the EGC would not.

 

[Smart $]

I'm not aware of a single instance, where a bare EGC is not code compliant. On...

There are actually several instances Code requires an insulated EGC. Here's one example...

550.33 Feeder.

(A) Feeder Conductors.Feeder conductors shall comply
with the following:

(1) Feeder conductors shall consist of either a listed cord,
factory installed in accordance with 550.10(B), or a
permanently installed feeder consisting of four insulated,
color-coded conductors that shall be identified by
the factory or field marking of the conductors in compliance
with 310.110. Equipment grounding conductors
shall not be identified by stripping the insulation.

(2) Feeder conductors...