Corner Grounded Delta Generator

[aelectricalman]

We have a service that was pulled off a pole by a semi. The service is a corner grounded 240V delta. Until the service is restored we need to get power to the facility. The service company sent us a Magnum Power Genset (by Generac). The ratings on the gen set are for
1 ph, 190 kVA - 240V
3 ph, 237 kVA 0.8 pf - 480/208
3 ph, 190 kVA 1.0 pf - 480/208

Is there any way this can be made ready for this application or will there be some winding reconfiguration. I've never seen a stand alone corner grounded genset. Thanks for any help.

 

[aelectricalman]

I feel like a three phase system doesnt care what the voltage looks like as long as I give it a 240 Volt service across all three legs. I could use the 208 option on the rotary voltage selector then crank the voltage up a bit to get it close to 240. The only drawback is the line to ground voltage will raise from 120 ish to about 135 ish, but who cares, the equipment is looking for 240V -3 phase only. Can someone tell me if Im forgetting anything important?

 

[GoldDigger]

Just make sure that there is no ground to neutral bond in the generator!
Actually, you also need to verify that the insulation in the windings and controls can withstand 220V to ground.
How about getting a transformer?

 

[iceworm]

Just make sure that there is no ground to neutral bond in the generator!
Actually, you also need to verify that the insulation in the windings and controls can withstand 220V to ground.
How about getting a transformer?

Imperative yes

and yes.

Possible alternate:
This appears to be a 12 lead gen with 120V - 139V coils. Ask the service company if they will reconnect to 240D and corner ground. It's not typical, but certainly possible.

I'd look for the transformer first.

ice

 

[aelectricalman]

Just make sure that there is no ground to neutral bond in the generator!
Actually, you also need to verify that the insulation in the windings and controls can withstand 220V to ground.
How about getting a transformer?

Transformer is the way....it looks. Thank you for you help.

 

[winnie]

For what its worth: A generator _is_ a transformer. If the proper connections are available, you can get the desired output.

See http://www.electrical-contractor.ne...cs/148753/12_Lead_Stator_Generators_Sche.html

A 12 lead generator has 6 separate coils. Each coil is rated to produce 120V (possibly 120-139V, to allow for 480V wye output). There are 2 coils for each phase. By suitably connecting them you can get 120/240V (derated single phase) 208/120V (wye) 240/120V (delta)...

If you connect for 240V delta and corner ground you would have exactly the output you want.

If the particular generator is rated to be connected for 480/277V wye, then the insulation system should have no problem with 240V corner grounded delta.

-Jon