Bare EGC in underground raceways

[peter d]

Is it permissible to use a bare "grounding" conductor in an underground or underslab raceway?

Does the less restrictive rule of allowing an EGC to be bare apply, or does the more restrictive rule requiring "W" rated conductors apply?

I know GEC's area often installed bare outdoors in direct contact with earth, so I'm thinking bare is allowed in a raceway. I just wasn't sure.

 

[rcarroll]

I don't think there's a problem with it except where specifically an insulated EGC is required. Like mobile homes, pools, patient care areas, etc.

 

[Dennis Alwon]

Is it permissible to use a bare "grounding" conductor in an underground or underslab raceway?

Does the less restrictive rule of allowing an EGC to be bare apply, or does the more restrictive rule requiring "W" rated conductors apply?

I know GEC's area often installed bare outdoors in direct contact with earth, so I'm thinking bare is allowed in a raceway. I just wasn't sure.

If the EGC is solid it cannot be pulled in a raceway if it is larger than #10.
Edited to add--- article 310.3

 

[LarryFine]

If the EGC is solid it cannot be pulled in a raceway if it is larger than #10.

Of course, you mean may not. I've seen it done.

However, now that I think about it, what about the solid #6 and #4 we often use for services GEC's? Are we not permitted to sleeve them? Hmm.

 

[Dennis Alwon]

Of course, you mean may not. I've seen it done.

However, now that I think about it, what about the solid #6 and #4 we often use for services GEC's? Are we not permitted to sleeve them? Hmm.

Of course-- people do sleeve them. I think that's okay-- you are just protecting it. I believe the reason is because solid wire does not bend well around bends and will cause extra hardship with other conductors in the conduit.

 

[tom baker]

If a bare EGC is used in a raceway, in a ground fault, it will heat and can damage the other conductors. An insulated EGC gives some protection. I have noted that bare copper conductors are 7 strand, and insulated are finer strand.