220v 3 Phase Transfomer Help

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i have a machine that asks for a 220v 3 phase supply
and i only have a 30kva transformer with 480/277 primary with a 120/208Y Secondary.
i am reading 212 volts between legs 123v to the Neutral.
Will that work ? Or
Do i need to Put another transformer?
 
The best answer will come from the machine manufacturer.
It depends on the type equipment. Often "220" is a generic term and the equioment will operate on 208, but that is not always the case.
 
Usually transformers come with taps (2 up 2 down).
If you change the tap from the 480V to 460V you should get 220V on secondary. 480 to 208 has a 0.43 ratio, 460 to 208 has a 0.45 ratio, hence applying 480V with a ratio of 0.45 you get about 220V

augie47 said:
The best answer will come from the machine manufacturer.
It depends on the type equipment. Often "220" is a generic term and the equioment will operate on 208, but that is not always the case.
Click to expand...
 
Strife said:
Usually transformers come with taps (2 up 2 down).
If you change the tap from the 480V to 460V you should get 220V on secondary. 480 to 208 has a 0.43 ratio, 460 to 208 has a 0.45 ratio, hence applying 480V with a ratio of 0.45 you get about 220V
Click to expand...

You also need to consider what the actual primary voltage is. Around here most of time a 480 volt service will normally operate around 495-500 volts.
 
kwired said:
You also need to consider what the actual primary voltage is. Around here most of time a 480 volt service will normally operate around 495-500 volts.
Click to expand...

I can not change to voltage there are other machines running on the 208 leg
i have found a transformer 480/277 Delta with a 3 Phase 120/240 delta should i use it ?
 
kwired said:
You also need to consider what the actual primary voltage is. Around here most of time a 480 volt service will normally operate around 495-500 volts.
Click to expand...

I can not change to voltage there are other machines running on the 208 leg
i have found a transformer 480/277 Delta with a 3 Phase 120/240 delta should i use it ?

3_phase_4_wire_delta_240d.png3_phase_4_wire_delta_240d.png
 
If your equipment is sensitive and requires pretty precise 220 volts you can use buck - boost transformers to obtain voltage needed. Otherwise 220 is about in the middle of 208 vs 240 systems, and would likely work with either in most cases. You really need more information from equipment manufacturer - maybe even just looking in an installation manual might answer your question.
 
If there are motors, the machine designed for 50 Hz will run faster on 60 Hz even if voltage is matched exactly. That likely will mean it will demand more HP than originally designed for because of the increased speed. Even if the machine can take the increased load the motor may now be overloaded.

If it is resistive loads only frequency will not matter.
 
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