480 to 416?

[edbukont]

We have a broadcast transmitter to install than can accept up to @ 440V. The manufactuer says 480V is not acceptable, and that 416 is the max preferred.

The utility says they cannot provide 416, but only 277/480 WYE (or otherwise something lower in the <240 range.

What sort of transformer do we need to suggest to the building prefrabricator should be researched to go from 480 (possibly Delta) to 416 WYE?

We realize this will need to be further reviewed by an electrical contractor or PE, but we are getting nowhere with the client's inhouse engineer, so we have to move the information dialog along.

Thank you

 

[don_resqcapt19]

They make transformers for that purpose. Take a look here.

 

[G._S._Ohm]

We have a broadcast transmitter to install than can accept up to @ 440V. The manufactuer says 480V is not acceptable, and that 416 is the max preferred.

What's the minimum?
Taking the average between this and 416 would probably give you the design center voltage.
You should also get max, min and avg. transmitter current draws at the voltage inputs.

IMO your supply voltage should be centered on the transmitter input voltage tolerance band, but not to exceed 416.

From Don's link, for 45 kva,
65 A @ 400 V and 63 A @ 415 V
implies a transformer output resistance of
(415-400)/(65-63) = 7.5 ohms and if the transmitter input current varies widely the input voltage may go out of the desired range.