GPE on square d switchgear...

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chevyx92

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VA BCH, VA
Has anyone had to troubleshoot the Ground sensing equipment on a 2000A Square D switchgear? Here's what I am referencing.

http://ecatalog.squared.com/catalog/173S/html/sections/03/SD173 03-48.html#

Situation, 2000A main switchgear ground fault in theatre in mall trips. We have no schematic. The ground fault reset would not reset, red light on reset button lit. We shut off all load breakers and ground fault reset still would not reset. There wasn't a whole lot we could do in this gear because of the line side (480V) being hot off the CT's. We troubleshot what we could, but without a schematic we didn't get far. We know that there is a problem with the GFPE because with the power "OFF" to it we could reset the 2000A breaker. But as soon as we turned the GFPE back on it would trip out. We temporarily kept the GFPE off so we could provide power back to the theatre and will have a Sqaure D tech with a schematic help out. Any ideas or insight on an item we overlooked?
 
chevy, If the gear has been in service for awhile and this problem just started showing

up now, I might be inclined to think that a GF problem exists.
 
chevyx92 said:
Has anyone had to troubleshoot the Ground sensing equipment on a 2000A Square D switchgear? Here's what I am referencing.

http://ecatalog.squared.com/catalog/173S/html/sections/03/SD173 03-48.html#

Situation, 2000A main switchgear ground fault in theatre in mall trips. We have no schematic. The ground fault reset would not reset, red light on reset button lit. We shut off all load breakers and ground fault reset still would not reset. There wasn't a whole lot we could do in this gear because of the line side (480V) being hot off the CT's. We troubleshot what we could, but without a schematic we didn't get far. We know that there is a problem with the GFPE because with the power "OFF" to it we could reset the 2000A breaker. But as soon as we turned the GFPE back on it would trip out. We temporarily kept the GFPE off so we could provide power back to the theatre and will have a Sqaure D tech with a schematic help out. Any ideas or insight on an item we overlooked?
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Seen many problems with these, hard to determine the problem with out some proper testing. Brian John (from this forum) is in your area and is very good with these systems. You are better off with him than the random tech Sq-D will send you (Next!). Get in touch with Brian john.
 
with the main off you should have been able to test for any ground fault condition that would trip the unit other than a line side power problem (if there was a problem on the line side I would imagine you would notice something unusual). did you meg to ground on load side phases ? did you shut off all the breakers on the mdp and check for ground fault conditions ? did you then check to see if the unit didn't trip with no loads in the closed posiition ? what tests did you do ? did you contact square d to get the information you need ?
 
nakulak said:
with the main off you should have been able to test for any ground fault condition that would trip the unit other than a line side power problem (if there was a problem on the line side I would imagine you would notice something unusual). did you meg to ground on load side phases ??
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We didn't meg but ohmed and found nothing wrong. Like I said the breaker will close with GFPE off.

nakulak said:
did you shut off all the breakers on the mdp and check for ground fault conditions ? ?
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Yes We did and found none on the load side of fuses.

nakulak said:
did you then check to see if the unit didn't trip with no loads in the closed posiition ? what tests did you do ? did you contact square d to get the information you need ?
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The GFPE still wouldn't reset even with no loads(all breakers off). We are contacting them on monday.
We believe the GFPE itself has a problem but like I said in the OP, you can't get to some of the equipment "SAFELY" to do more testing unless we have POCO shut building down.
 
Since this is in a theatre, ask the theater manager or projectionist if they have had any failures of the Xenon lamp power supplies recently.

Modern switching power supplies have "high leakage currents" and can cause issues with GFP.

It is possible one or more supplies has issues.

Shut off ALL breakers in each booth subpanel and check things again. If the GFP holds, try turning on the breakers in those subpanels one at a time and you'll find the one causing the problem.
 
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