In a JAM

[puckman]

My utility is a 3 phase 3 wire 480v corner grounded service. We had a stand by gen ordered to the site in case its needed for this job. the gen people hooked up a 3 wire 480volt gen . MY QUESTION is will the gen do the job if needed. it is not a corner grounded feed , its a straight 480 volt gen feed. We don't need 277v.

 

[kwired]

My utility is a 3 phase 3 wire 480v corner grounded service. We had a stand by gen ordered to the site in case its needed for this job. the gen people hooked up a 3 wire 480volt gen . MY QUESTION is will the gen do the job if needed. it is not a corner grounded feed , its a straight 480 volt gen feed. We don't need 277v.

That will depend on how things are done. The installation should still have separate equipment ground from grounded conductor (which also happens to be a phase conductor). If the grounded phase is ran through circuit breakers as is permitted you may just need to remove the system bonding jumper to isolate that phase from the EGC, and things will work just fine. If the grounded phase is attached to a bus, you will have overcurrent protection issues everywhere on the system with that phase when it is no longer a grounded phase.

Another option will depend on if you are able to ground a phase of the generator or not. The 480 volt 3 wire equipment will not care if it is wye or delta, just if it is receiving 480 volts.

 

[puckman]

Kwire, thanks for the help.

 

[Jraef]

... We don't need 277v.

You never had it anyway...

 

[puckman]

Thanks again , out of the jam.