# Can I and how do i with this Transformer



## Jpelectricalsolution (Dec 16, 2010)

I have a Primary voltage 480v delta to 120/208 Y secondary 3 phase. I want to know if I can Change the taps on it to turn it into and 208/240 primary Delta to a 120/208 Y 3 phase? If so how?


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## rlc3854 (Dec 30, 2007)

From your experience and knowledge, what do you think the taps are for? What is the purpose that you want to do this and what is the transformer KVA?


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## micromind (Aug 11, 2007)

Each coil on the primary side is 480 (or thereabouts). There isn't any way to make it work with 240 and still get 120/208 on the secondary.

Rob


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## brian john (Mar 11, 2007)

The coils are 4 to 1 with 5% over and 10% under, there is no 208/240 except with a high leg delta which is 240/120-208 high leg

Below is what you would get if you connected the primary at 208 delta and at 240 delta.

Tap 1-4.2 to 1 At 208 Primary at 240 Primary 85/49 98/57
Tap 2-4.1 to 1 At 208 Primary at 240 Primary87/50 101/58
Tap 3-4.0 to 1 At 208 Primary at 240 Primary90/52 103/60 
Tap 4-3.9 to 1 At 208 Primary at 240 Primary92/53 106/61
Tap 5-3.8 to 1 At 208 Primary at 240 Primary94/54 109/63
Tap 6-3.7 to 1 At 208 Primary at 240 Primary97/56 112/64
Tap 7-3.6 to 1 At 208 Primary at 240 Primary100/57 115/66 

And that is what you have

I am assuming you have a 240 delta system and need 208/120 wye?

Here is what you want.



http://www.solahevidutysales.com/general_purpose_distribution_transformers.htm

http://www.solahevidutysales.com/pdf/transformers/GenPurpose.pdf

240 Delta-208/120 wye from Sola Hevi Duty Transformers
ET6H15S15WS-0236.141.7ET6H30S30WS-1472.383.4ET6H45S45WS-14108125ET6H75S75WS-30181208ET6H112S112.5WS-30271313ET6H150S150WS-10361417


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## Jpelectricalsolution (Dec 16, 2010)

brian john said:


> The coils are 4 to 1 with 5% over and 10% under, there is no 208/240 except with a high leg delta which is 240/120-208 high leg
> At 208 Primary at 240 Primary
> Tap 1-4.2 to 1 85/49 98/57
> Tap 2-4.1 to 1 87/50 101/58
> ...


Yes we have a 120 208/240. We just had this transformer in the shop and was just wondering if it was possible to re-tap it and make it work, we already ordered the correct transformer just thinking we can make a higher profit "if" making this one work was possible, no big deal, was just curious. It is a 45KVA transformer by the way. Installing a UPS for Cisco systems.
Thanks for the help!


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