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Posted By: Yoopersup Overhead Three Phase 13.8 & 4160 Delta - 06/28/11 04:16 PM
Overhead 13.8 & 4160 Delta no neutral present.
Running to remote building . Owners Not Utilitys.
When you come down pole to Step down Transformer where & how do you ground?
If ungrounded delta how does it trip ocp , located remotely??
Remember its Owners , Not Utlity so there Feeders!
Yoopersup
You ground / bond to the case of the transformer.

The OCPD trips only after the SECOND line faults to ground. That's why phase monitors are required.

Non-NEC compliant solution: Slap the foolishness out of this customer- there's no reason to preserve an ungrounded delta.
Posted By: Yoopersup Re: Overhead Three Phase 13.8 & 4160 Delta - 06/29/11 12:51 AM
Design By Electrical Engineer!
Phase monitors on a overhead line? 4160.
Or 13800 volts?? Please give details .
Posted By: gfretwell Re: Overhead Three Phase 13.8 & 4160 Delta - 06/29/11 04:49 AM
The medium voltage lines around my area seem to have some kind of impedance grounding going on. You see a funny looking insulator device connected to ground every so often along the line. I suspect this is just a path for lightning,
Originally Posted by Yoopersup
Design By Electrical Engineer!
Phase monitors on a overhead line? 4160.
Or 13800 volts?? Please give details .


Ya sérieux ??

What kind of ground fault detector you have or will set up most common in MV/HV class will have impleaded or resteror grounded or netural set up depending on the supply format is.

And you will need phase monitor to detect the ground fault on them and some case you may need automatique recloser { this part I am not too crazy but it do work very well }

Merci,
Marc
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