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Feeder loading

Feeder loading

Feeder loading

(OP)
Dear colleagues,
We need to connect a 800 kVA transformer (480/480)to user grid. The available single  busplug is sized for approximately a half of transformer FLA. Is it possible and/or legal to use 2 busplugs to feed a transformer via 2 parallel branches (assuming their equal length)?

RE: Feeder loading

My question would be are the bus plugs physically close together. If so you could bring the conductors into a fused disconnect switch and on to the transformer. The fuse would be size for the transformer per 450.3(B). The scondary would be protected per 240.21C.

RE: Feeder loading

(OP)
I would like to clarify my question: I am talking about 2 fusible busplug tap-offs which in sum provide needed ampacity, can I feed a single load (transformer) from 2 parralel and protected (?)branches?

RE: Feeder loading

I don't see a section in the code (NEC) that prohibits it, but it may not be the best practice.

Mike

RE: Feeder loading

Not according to the NEC.

Article 240: "Fuses and circuit breakers shall be permitted to be connected in parallel where they are factory assembled in parallel and listed as a unit. Individual fuses, circuit breakers or combinations thereof shall not otherwise be connected in parallel."

RE: Feeder loading

(OP)
Alehman,
Thanks for very good reference.

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