Confused

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Richterfan

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Ok so I am having a brain fart here I think. Can anyone tell me what size trans I need because when I figure it out by what they list it doesn’t add up.
I have a new 30kva trans 480v pri 36.1a / 208v sec 83.3a. I have 208v 3ph and have to step up to 480v 81A75ADF-4057-412D-892A-ED11155BF361.jpegand was going to reverse feed this trans but the 20kva trans that they recommended doesn’t seem large enough.
 
Using a standard xformer in reverse is a terrible idea for a number of reasons. Best to get a proper 208 delta X 480Y unit. Didn't check the sizing.
 
texie said:
Using a standard xformer in reverse is a terrible idea for a number of reasons. Best to get a proper 208 delta X 480Y unit. Didn't check the sizing.
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I had asked the square d supplier and he had said this trans can be done this way. It’s what they had recommended I use but not sure what to use with the document I listed.
 
Letting a supplier engineer for you is not the best idea.

Roger
 
roger said:
Letting a supplier engineer for you is not the best idea.

Roger
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I agree but I told them what I needed according to the document I attached and they said these can be wired both ways. He is not engineering this but I asked and this is what he said will work.
Do you have the answer? I posted on here for my dilemma of what’s listed on the paperwork but seems I am getting responses to something different.
 
The numbers you show are the correct currents for the 30kva.
From what I see in the picture it seems they are calling for a 50kca which would provide 60 amps (75 usinga 125% allowable factor)
 
augie47 said:
The numbers you show are the correct currents for the 30kva.
From what I see in the picture it seems they are calling for a 50kca which would provide 60 amps (75 usinga 125% allowable factor)
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Thanks Augie, what do you make of the specs that says 220/480 requires a step up transformer (20kva) recommended. This is the part that is throwing me off.
 
can not read to document spictured well enough to have an opinion
 
You're right, that is weirdly contradictive. If it needs 60A and 50kVA, you are not going to get that from a 20kVA tranny. You are not going to get 60A at 480 from a 30kVA tranny either for that matter. It's definitely worth a phone call to Amada.

Side note: "220/480"? not 240/480 or 220/440? Maybe this was written by someone in marketing who has no clue...
 
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