My transformer is enough for my application?


Thread Starter


I have one transformer with this specs: 3 phases 600V/240 (delta) 45Kva

This transformer will give power to a distributor panel (15Amp braker)

I will have 57 motors 3 phases, 240V, 1hp

How can I calculate if my tranfo is enough for all motor?

P=240V*4A*57=54720VA?? that's right?

This motor will be connected with drive. Thanks!

Bob Peterson

If each motor draws 4A, than 57 running motors takes

57 * 4 * 240 * SQRT(3) VA = 95 kVA

No offense but it sounds like maybe you are in over your head on this one and should get some help from someone who knows a little more about this kind of thing.

Phil Corso, PE

Responding to Dany's Mar 14, 9:44pm query... sizing criteria requires more data than you have already provided:

A) Connected motor kVA equals 57 x sqrt(3) x 0.24 x Amps.

B) Obviously the selected transformer is too small, unless load-factor is known.

C) Load Estimation Factors are required to properly size the Xmr! However, if a like installaton is already operating, then, such factors can be easily determined from energy metering!

Contact me if details are required!

Regards, Phil Corso, PE {Boca Raton, FL, USA} [[email protected]] ([email protected])