Transformer windings, single phase step-up xfmr

[Dale001289]

I want to feed a single phase, step up transformer, 10kVA with 120V from a local panel, (i.e. Hot and Neutral). The Xfmr has a 120/240V primary winding and 240/480V secondary winding. I want 480V on the secondary. Will this give me 480V phase to Neutral on the secondary?

 

[xformer]

How are the taps on the secondary configured?
Are they just two taps or 2 taps with a center tap?

 

[Jraef]

I want to feed a single phase, step up transformer, 10kVA with 120V from a local panel, (i.e. Hot and Neutral). The Xfmr has a 120/240V primary winding and 240/480V secondary winding. I want 480V on the secondary. Will this give me 480V phase to Neutral on the secondary?

No, it will give you 480V line to line single phase. If you grounded one side you might call that a "neutral", but that would be a highly uncommon need for anything that needs a 480V single phase input.

 

[Dale001289]

No, it will give you 480V line to line single phase. If you grounded one side you might call that a "neutral", but that would be a highly uncommon need for anything that needs a 480V single phase input.

Thanks, I also understand there's a UL standard that requires transformers to be labeled with the proper windings - in other words, if its being used as a step-up transformer, you cant simply feed a step down in reverse.
would you happen to know which standard this is?

 

[kwired]

Thanks, I also understand there's a UL standard that requires transformers to be labeled with the proper windings - in other words, if its being used as a step-up transformer, you cant simply feed a step down in reverse.
would you happen to know which standard this is?

Been recent changes in NEC on this during past couple code cycles. Basically the transformer must be designed to be "backfed". Smaller units typically are not designed for this, larger units may have greater chance of being designed for this without needing to special order one.