60 kw 3 phase generator

[TheCrow]

Hooking a 60 kw generator to a manual transfer switch . 3 phase power at transfer. 120 to ground all legs. And 240 across phases.
On the load side power goes to a corner tap transformer secondary sides getting readings
A to b 240
B to c 120
A to c 120
A to ground 120
B to ground 120
C to ground 120

 

[LarryFine]

3 phase power at transfer. 120 to ground all legs. And 240 across phases.

You're reading delta and wye voltages from the same system. I don't think that's possible.

On the load side power goes to a corner tap transformer secondary sides getting readings
A to b 240
B to c 120
A to c 120

Those voltages are even more bizarre.

A to ground 120
B to ground 120
C to ground 120

Those are normal wye voltages on a 208Y/120 system.


Are you using a voltmeter or a voltage tester?

 

[Todd0x1]

None of this makes any sense. Can you post a picture of the dataplate on the transformer? Does the transformer sit between the generator and the transfer switch? If not where in the path is the transformer?

 

[don_resqcapt19]

If the generator is ungrounded and there is no load you could get those readings as the voltage to ground would be the capacitive coupling and with a limited amount of wire and no load those readings are possible, assuming a high impedance meter was used.

Have seen the same thing with 277 volt readings to ground with a 3 phase 480 volt ungrounded system.

The voltage to ground will disappear if you use a solenoid voltage tester or a low impedance meter.

 

[Hv&Lv]

Your missing something or it’s not connected right.