Originally Posted by BigJohn
I have a couple of buck-boost transformers that I think are grossly undersized, and I'm hoping someone can check my math:

Two 3kVA, 600V, delta-connected auto-transformers should have a line current of 5 amps, correct?

3000VA * 2 * 0.87 (because it's an open delta) / 1.73 / 600V primary = 5.0A

Thanks a bunch.

-John


BigJohn.,

I came up complety diffrent number than your numbers.

Here is my verison.,,

3000VA X .87 ÷ 1.73 ÷ 600 = 2.51 amps

The 1.73 is allready taken care for triphase { it dont matter if open delta or close delta or wye format }

But just wondering why you add X 2 in there so if you try that again like my formaila and also I did used the electrician caluacator to see and the answer and it came pretty close it show 2.8amps on that one.

Merci,Marc

Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)