Tapes Supplying a Transformer (Cables length)

[ilan7]

I'm planning to install new 2.5 MVA, 13.8/0.48 KV transformer. According to the NEC 240-21 Para. 3, the maximum tape condactors total length (Primery and secondary condactors) is no more then 25 ft. The Transformer equipped with oil immersed fuses at the primery (13.8KV).
Does anyone have an idea how can I have more cable length? does the fuses help to inlarge the cables langth?
Thanks to all.

 

[GamezBeCJ]

What exactly do you mean by tape conductor?

 

[busbar]

Possibly a typo—maybe should be "tap conductor".

 

[davidbeach]

240.21(B)(3) only applies where the primary is not full capacity, is itself a tap. Where you have full capacity primary protection, which your immersed fuses should be providing, use 240.21(C). If your transformer is outdoors, 240.21(C)(4) will let you put the secondary overcurrent protection far enough away to have it inside the building. If you are starting inside, 240.21(C)(6) will get you 25 feet of secondary conductor.

 

[wareagle]

Read 240.1. Parts I thru VII do not cover your installation.
Part IX covers installation if systems over 600 volts.
250.180.

 

[davidbeach]

The transformer secondary circuit at 0.48kV (otherwise known as 480V) falls under the requirements of 240.21. The feeder to the transformer would fall under the requirements of part IX, but the original question is about cable length and secondary cable lengths are per 240.21(C).