Ground wire size

[prattz99]

Hi All,
I called my local electrical inspector today to ask a question about the pool house feeders and sharing a trench with the water line. I told him I'm planning on running a 2/0 2/0 #1 Al Converse direct burial with a #8 Cu green as the equipment ground for the pool house sub panel. He told me that it needs to be a #6 Cu. Am I using the right table? I thought because it's not service related and the feeders will be protected from the main house using a 100 amp circuit breaker that I would be within compliance of the NEC based on Table 230.122

He said a few other things that make me question his degree of competence.... What would you guys do?

 

[augie47]

I have not done the math but the inspector is probably correct as your phase conductors are upsized for a 100 amp circuit, the equipment ground must be proportionally increased also {250.122(B)}
Side Note: We can not ue Converse cable as it is ot a recognized Art 310 conductor.

 

[Dennis Alwon]

I don't believe you can use direct burial cable for the feeder to the pool.

 

[augie47]

I don't believe you can use direct burial cable for the feeder to the pool.

That was my 1st thought but in '17 the wording changed to "Where installed in noncorrosive environments, feeders shall comply with the general requirements in Chapter 3."
Would that not allow direct burial ??

 

[Dennis Alwon]

I guess it would but there's no way in h*** that I would ever do that

 

[Dennis Alwon]

As some of you know we had a tragic accident in Raleigh, NC involving under ground cable. In this case it was spliced underground and eventually the splice failed and a lifeguard who was cleaning the pool got killed... Her first day on the job....

 

[infinity]

He told me that it needs to be a #6 Cu. Am I using the right table?

I think that he used the wrong table {250.66} unless he specifically noted the reason that Augie mentioned in post #2.