12,470V dredge cable ground wire monitor

[dithomas]

My question has to do with providing for ground wire monitoring when there is a 12,470 3 phase pole line at the dredge location and the dredge is fed from a 12,470 trailing cable. dredge is in the USA.

Is there a need for a 12,470 delta/wye isolation transformer at the base of the pole in order to establish an isolated resistance ground for the trailing cable or can the 3 phase wye system from the utility be used to feed a skid mounted breaker and isolation switch with a ground wire monitor device?

I hope my question makes sense. Thanks in advance.

Dan

 

[lansford]

You need to install the transformer to establish a new isolated system for your resistance grounded system.
The utility multi wye grounded system cannot be used by just putting in a grounding resistor at your location.
Jim

 

[dithomas]

Jim,

Thanks for the reply.

Would it make a difference if the 750kVA 12,470V isolation transformer had Y-Y windings rather than D-Y windings?

Dan