3000 amp 480 volt Service Entrance

[shortckt70005]

I have a job where there is a new utility transformer being installed with a 3 Phase 3000 amp 480 volt secondary coming into the building. There are 8 parallel PVC conduits that are shown on the print that run about 90' to the new building. The conduits are 24" below grade. Is it ok NOT to have it encased in concrete? Prints do not show in concrete and are pretty vague.

Thanks
Daryl

 

[infinity]

Since you've met the required burial depth concrete encasement would be a design option not a code requirement.

 

[Choice_Gorilla]

Wouldn’t it be up to your POCO? You are still on the line side of the service disconnect correct?

 

[shortckt70005]

Wouldn’t it be up to your POCO? You are still on the line side of the service disconnect correct?

Yes I am talking about on the line side of the Switchboard...I have never installed a parallel service this large (3000 amps) that did not have a duct bank. but it does meet minimum code+.

 

[Choice_Gorilla]

Last one I was apart of was encased in concrete because the power company required it for the secondary side service conductors. (Encased from utility pad mount transformer into switchgear inside building). I would look up your local utility company’s standards for electric service.

 

[shortckt70005]

I will check with utility company and the Parish Chief Electrical Inspector tomorrow.....beside just being 2' to the top of conduit the trench is within 10' of a10,000 gallon underground Diesel tank. Now it changes Classifications of the underground. I don't think this EE is correct in this application.

 

[mikeames]

Now it changes Classifications of the underground. I don't think this EE is correct in this application.

Conduits underground, 10 feet away from an enclosed tank underground is not a classified location in 500.5. It would be hard to argue even a Div 2. Even if it was the conduits are just passing through the area unbroken. Ask the engineer to support his claim of a classified area.