Generator Reactances

[nhcf]

We have a standby generator - 480/277 V.

The vendor has provided p.u. reactance data for a 139/240 configuration.

I should be able to convert the p.u. to ohms and back to 480, correct? I am uncertain as to how the windings are reconfigured in the 480 application - is it as simple as doubling the ohm value prior to converting back to p.u.?

 

[waross]

The windings are either in series or parallel.
4 times may work better than double.

EG: Each winding = 2 Ohms.
Parallel = 1 Ohm
Series = 4 Ohms.
Current at 480 Volts = Volts x 2 divided by the resistance times 4 = 1/2 the current.

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

 

[nhcf]

yes, that makes sense. thanks, waross.