Oil filled pad mounted transformer

[Sparky2791]

Does an outdoor oil filled pad mounted transformer require a ground wire be brought in with the feeders. I am thinking a supply side bonding jumper is required but the code takes you through steps that seem be exceptions make it not required. For example 250.30 A (2) Exception but I do not understand the requirements of 250.30 (A) (1)

Thanks for replying

 

[tortuga]

I think an oil filled outdoor transformer would meet 250.30(A)(1) Ex.2 [I am on 2020 NEC] no?

 

[Sparky2791]

I think an oil filled outdoor transformer would meet 250.30(A)(1) Ex.2 [I am on 2020 NEC] no?

That is what I am seeking guidance on but I believe you are correct. The ground is established at the service entrance so no need to pull a ground wire in with the service conductors? Can anyone clear up that exception? By the way I am under 2014 NEC.

 

[tortuga]

The ground is established at the service entrance

Are we talking about a service or feeder?
I was picturing a campus type setup where you have something like 480V feeders to the oilfilled then 280/120 to said building.
Where is the service point?
Here is a info graphic from the 2014 handbook:

 

[jim dungar]

For the most part, the actual transformer voltages are not important, a 12470V delta primary to a 480Y/277V wye secondary would require basically the same connections as a 480V delta to 208Y/120V transformer.

The fact the this transformer feeds a building versus a lighting panel is not important. The secondary is not an NEC service.