Location of Building Main Disconnect

[jbt260]

I have a customer owned 2300V-480/277V outdoor transformer fed from the customer's 2300V distribution. The secondary conductors run underground approx 200' then enter the lower level of a building then up one floor to the main breaker.

My question is: How far can I run inside the building from point of entry to the main breaker? Or do I need O/C protection right at the point of entry, or even outside prior to entry?

Thanks,

 

[jwjrw]

I believe that is up to your AHJ.

 

[charlie b]

It may also be up to your local codes. In my state, the limit is 15 feet. I don't know if Ohio has its own limit. The NEC does not give a limit. But I have taken advantage of the rule that says the conductors are still "outside the building," if you surround them with 2 inches of concrete.