Transformer help please

[petersonra]

You can get a ground detector or make your own.

Buy 3 600VAC lights.

Wire each one from a phase to ground.

All should glow.

If you get a grounded phase, the light on the grounded phase will go out and the other two lights will be bright.

Put them in the electrician's break room.

 

[augie47]

"so he recommended"......
I would have thought he would have required....

"250.21 Alternating-Current Systems of 50 Volts to 1000 Volts Not Required to Be Grounded................
(4) Other systems that are not required to be grounded in accordance with the requirements of 250.20(B).
Where an alternating-current system is not grounded as permitted in 250.21(1) through (4), ground detectors shall be installed on the system

 

[iwire]

You can get a ground detector or make your own.

Buy 3 600VAC lights.

Wire each one from a phase to ground.

All should glow.

If you get a grounded phase, the light on the grounded phase will go out and the other two lights will be bright.

Put them in the electrician's break room.

A fool proof notification system.

 

[kingpb]

Use of a zig-zag for ground will work, but these transformers are expensive and not easy to come by. One of the most effective ways to detect ground fault on an ungrounded system is to use a 59 relay and measure the zero sequence voltage across a resistor.

I recommend you get an engineer, familiar with system protection involved for this application.