# Thread: 30kva 3phase step up transformer

1. Junior Member
Join Date
Jan 2018
Location
Loves park,Il United States
Posts
2
Mentioned
0 Post(s)
Tagged

## 30kva 3phase step up transformer

Pratch
Junior Member

Join DateJan 2018LocationLoves park,Il United StatesPosts1

30kva 3phase step up transformer

I am running power for a sasso k600 extreme Cnc saw and it comes with a 30kva 3phase step up transformer.the saw requires 400volts, the transformers primary side is 230 volts and secondary side is 400 volts. The normal running amps for saw is 80 and a max of 125.so my ? Is what size wire do I need to run to the primary side of transformer and what amp breaker. And then what size wire coming of the secondary side going to saw? I'd appreciate any help

2. Senior Member
Join Date
Jan 2014
Location
chicago, il, USA
Posts
417
Mentioned
0 Post(s)
Tagged
This is a link that should help, it covers pretty much everything about transformer calcs thay pertain to your question.

http://www.mikeholt.com/mojonewsarch...n~20020516.htm

3. Originally Posted by Pratch
Pratch
Junior Member

Join DateJan 2018LocationLoves park,Il United StatesPosts1

30kva 3phase step up transformer

I am running power for a sasso k600 extreme Cnc saw and it comes with a 30kva 3phase step up transformer.the saw requires 400volts, the transformers primary side is 230 volts and secondary side is 400 volts. The normal running amps for saw is 80 and a max of 125.so my ? Is what size wire do I need to run to the primary side of transformer and what amp breaker. And then what size wire coming of the secondary side going to saw? I'd appreciate any help

If normal running amps is 80 amps @ 400 volts - your 30 kVA transformer seems undersized to me 80 x 400 x 1.732 = 55.4 kVA.

4. Originally Posted by kwired
If normal running amps is 80 amps @ 400 volts - your 30 kVA transformer seems undersized to me 80 x 400 x 1.732 = 55.4 kVA.
I agree. Seems to me that there are two different threads running on this same topic. I responded to the other giving input and output current ratings for the 30kVa transformer. But essentially the same conclusion that you came to.

5. This is the second thread, I am closing it. The points made are however very valid and I encourage you to check your requirements.

Here is the original thread for reference or further discussion. Eventually I'll merge relevant posts into it.