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Power Load Question

Power Load Question

Power Load Question

(OP)
I have a 480V 50A Breaker, with a transformer 480V/120V that's 25kVA, and a power panel pulling 15A.
Can I add another power panel to the transformer pulling 50A if I increase the main breaker to 100A?
If not, then what's my limiting factor the transformer or the breaker?

RE: Power Load Question

What do your calculations show?

RE: Power Load Question

Code requirements are the limiting factor. Check the NEC.
From your description, I strongly suspect that your present installation is not in compliance.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Power Load Question

is this single phase or 3 phase?

RE: Power Load Question

(OP)
3 phase

RE: Power Load Question

Like Davidbeach said, what does your calculations say?

I suspect the max CB allowable for your TX is 50A. i doubt you can increase it to 100A. You might have to increase the TX size, but again, that depends on your calc/studies. If you do, remember you need to make sure your Panel and your cables are rated for the new ampacity of 100A.

RE: Power Load Question

I would say that the breaker is your limiting factor as your secondary side can handle 122 amps.

RE: Power Load Question

Mary -
Let's get a little bit clearer on the system: We got "480/120", "3 phase", "25kVA".

I've never seen a 25kva, 3ph transformer. That is a single phase size. 3ph would be 30kva.

If the system (transformer and panel, not the 480V feeder) is 1ph, then I would expect 480/240/120

If 3ph, then 480/208/120.

Of course you could have 1ph, 480/120. Not very common, but there are some.

So, what is the system?

iceworm

Harmless flakes working together can unleash an avalanche of destruction

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