Delta - Wye Transformer -- Have I spec'd correctly??

[hex4def6]

Hello everyone,

Quick question:

I'm spec'ing a transformer to take an input of 277V Delta, and to output 480V Wye. Please see the attached photo, and tell me if I've made the correct choice

One confusion I have is that the specs show the Sec. Voltage as 208Y/120 -- I assume this is for the taps listed, since they then have a bunch of different tap orders lower on the sticker? If this is the case, why do they even include it??

This is not my field of expertise here, so I'm hoping I didn't just waste a thousand bucks on an incorrect rental

Thanks all!

 

[kgil]

It looks like if you change the taps, you will be fine.
I assume that you meant a 480 delta on the primary.

 

[rbulsara]

That picture is of a 480V delta primary and 208Y/120V secondary unit, which is a normal configuration in the USA.

277 is the L-N voltage in a 480Y/277 system. L-L is 480V. Like wise
120 is the L-N voltage in a 208Y/120 system and L-L is 208V.

Not sure what you are talking about when you say 277 delta and 480 wye.


Rafiq Bulsara

http://www.srengineersct.com

 

[VTer]

there is no 277V Delta - the 277V is the line-to-neutral voltage on the 480V wye system. What are you trying to accomplish? If you have 277V then you have 480 wye as well, in which case I do not see a reason for the transformer.

"Throughout space there is energy. Is this energy static or kinetic! If static our hopes are in vain; if kinetic — and this we know it is, for certain — then it is a mere question of time when men will succeed in attaching their machinery to the very wheelwork of nature". – Nikola Tesla

 

[waross]

Stop, take a deep breath and start over.
As VTer says, there is no such standard voltage as 277 delta.
What voltage do you have and what voltage do you need?
Given the somewhat confusing primary tap information, is it possible to post a picture of the transformer with the cover off showing the physical taps?

Bill
--------------------
"Why not the best?"
Jimmy Carter