480 versus 460

[Thom Peterson]

Many years ago we changed taps on a plants transformers to increase voltage to 480. There were calculated savings from this. I can't find those calculations (too many years passed). I believe most of the savings was from motors running cooler and less amps. Can anyone shed some information to get me started in the right direction?

 

[Ed MacLaren]

Re: 480 versus 460

I believe most of the savings was from motors running cooler and less amps.

I believe you are correct.

The increased voltage results in a corresponding reduction in motor current. This reduces losses in service, feeder, and branch circuit conductors, and in the motor windings.

Ed

 

[templdl]

Re: 480 versus 460

480v is nominal. Consider 480y/277, 208y/120, etc. Some people consider 120v systems as 115 or 110 and 240 as 230 or 220v. If it is a 460y wouldn't the L-N voltage be something like 266v which is a strange figure.
However, what would be the actual voltage at a given position in a distribution system. With voltage drops considered 460v may be closer to being realistic and motors work best at their nameplate voltage.