GFCI Not Resetting Causes

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Desert Spark

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I'm doing some work on a ranch where there was a service feeding a mobile home via a 50a fused disconnect. At some point someone tapped off of a single line on the load side of the disconnect, and ran it, along with a neutral conductor, underground to a bunk house.

In the bunkhouse there was a small panel and the single hot was ran to both L1 and L2, and there were some single pole breakers installed feeding a few circuits in the bunkhouse.

I installed a new service panel, with a 50a breaker feeding the mobile home, and planned to run a 50a 2-pole circuit over to the bunkhouse and install a new sub-panel. Of course its never simple, the conduit going underground was simply 90ed and then the two conductors were direct buried. That has delayed the pulling of the new feeders.

Anyway, I got the new sub panel installed and ran new circuits for a fridge, and a 120v hot water heater. There was some other troubleshooting to do in the bunkhouse so I temporarily energized the panel to see if I could make use of the time I was there to do that. I wanted to test the new GFCI's first and with no other circuits on I energized the two dedicated circuits that I had just ran. The GFCI's would not reset. I knew that the ground was open but also that GFCIs don't need one to function so I had to scratch my head a bit.

Out of curiosity I installed the bonding screw in the sub panel, where the neutral had previously been isolated, and the ground installed on the can, but was really just floating. After that, the GFCIs would reset and function properly.

Im kind of at a loss on this. I know there may be other wiring issues in the bunkhouse given how work was done previously, but I don't understand how the new circuits I had just ran directly from sub-panel to GFCI would be affected by those issues, given that no other circuits were energized.

Didn't have a lot of time to try to figure that out but I am gonna see what happens once I get the new feeders installed. For now I just wanted to run it by the forum and see if there is something I am missing or should have checked.

Thanks
 
1. Be sure to remove the bonding screw, presuming there is a separate EGC.

2. Try a standard breaker; process of elimination.

3. Look for an accidentally-grounded neutral everywhere.
 
You mentioned the GFI's wouldn't reset,,, not that they tripped.

Evidently you installed GFI Receptacles, not GFI Breakers.

Seeing as how these were the only 2 circuits you energized in the subpanel, and, the GFI's didn't reset until you bonded the neutral and the ground at the subpanel, It seems the GFI's were not receiving power in the first place to the electronics, for the reset buttons to operate.

Sounds to me like you have some unfinished business at the Ranch house in the 50amp feeder to the bunkhouse.

JAP>
 
Sounds to me like the 50 amp neutral may not have been landed at the Ranch House panel.

JAP>
 
You don't really say it outright, but I'm assuming that the GFCIs are receptacles.

Frankly, it sounds like there is a mis-wire in the connection to the GFCI. Polarity reversal or supplying the LOAD terminal(s) will cause the sensing electronics, upon first initialization of the GFCI, to prevent the first mechanical reset from the RESET button.
 
al hildenbrand said:
You don't really say it outright, but I'm assuming that the GFCIs are receptacles.

Frankly, it sounds like there is a mis-wire in the connection to the GFCI. Polarity reversal or supplying the LOAD terminal(s) will cause the sensing electronics, upon first initialization of the GFCI, to prevent the first mechanical reset from the RESET button.
Click to expand...

He mentioned when he bonded the neutral to the ground at the subpanel that they worked properly.

If the polarity was wrong at the receptacles themselves, bonding the neutral and ground at the sub panel wouldn't have resolved the issue.

JAP>
 
jap said:
He mentioned when he bonded the neutral to the ground at the subpanel that they worked properly.

If the polarity was wrong at the receptacles themselves, bonding the neutral and ground at the sub panel wouldn't have resolved the issue.

JAP>
Click to expand...
Good point. What is it that Emily Litella says:

image.jpg
 
LarryFine said:
Actually, that was Nanna Roseannadanna, as told by Roseanne Roseannadanna.
Click to expand...

Nope, Al's right. "Nevermind" was an Emily thing. Roseanne was a different character and did the news with Jane Curtain.

https://en.wikipedia.org/wiki/Emily_Litella

"The news anchor would interrupt Litella to point out her error, along the lines, "That's death penalty, Ms. Litella, not deaf ... death."[4]Litella would wrinkle her nose, say something like, "Oh, that's very different," then meekly turn to the camera and say, smiling, "Never mind!"[5]"
 
Thanks for the replies.

To clarify, yes they are GFCI receptacles. Currently there is only a a single ungrounded and grounded conductor feeding the sub-panel, no EGC.

I wired the sub-panel like you would normally, with an isolated neutral, but no EGC therefore an open ground on the whole bunkhouse.

When I tried to reset the GFCI's this was on the initial energizing of the two circuits. New GFCI receps, no load whatsoever. When they did not set, I bonded the ground and neutral in the sub-panel, giving the ground a fault path back through the neutral. After that the GFCIs reset.

When they did not reset initially I did check for voltage at the breaker first thing, only with a NCVT, I know its not 100% but I'm pretty dang sure they were getting power.

I changed nothing other than the bond screw. I guess I will have to see if the same thing happens again if I remove the screw.

I still have to run the proper feed from the main panel, I just figured even though its just the two wire circuit with no egc, the receps should have still worked properly with the open ground at the sub-panel.
 
Desert Spark said:
When they did not set, I bonded the ground and neutral in the sub-panel, giving the ground a fault path back through the neutral. After that the GFCIs reset.
Click to expand...
To me, this sounds like the incoming grounded conductor and the GFCI white wires were not connected to the same bus. In other words, you connected one to the panel's EGC bus and the other to the panel's neutral bus, and it took installing the bonding screw to make the connection.
 
LarryFine said:
To me, this sounds like the incoming grounded conductor and the GFCI white wires were not connected to the same bus. In other words, you connected one to the panel's EGC bus and the other to the panel's neutral bus, and it took installing the bonding screw to make the connection.
Click to expand...

Or the neutral is open in the feeder to the sub panel. The bonding screw would then allow the ground in the feeder to serve also as the neutral.
 
Desert Spark said:
Currently there is only a a single ungrounded and grounded conductor feeding the sub-panel, no EGC.

I wired the sub-panel like you would normally, with an isolated neutral, but no EGC therefore an open ground on the whole bunkhouse.

I bonded the ground and neutral in the sub-panel, giving the ground a fault path back through the neutral. After that the GFCIs reset.

I changed nothing other than the bond screw.

the receps should have still worked properly with the open ground at the sub-panel.
Click to expand...

The GFI Receptacles will work properly with an open ground at the subpanel, but, they will not work if the Neutral conductor coming from the Receptacle is landed on the "Ground Bar" in the subpanel instead of the "Neutral Bar" in the panel.

I'm with Larry. Sounds like you landed the neutral coming from the GFI receptacles on the ground bar in the subpanel instead of the neutral bar. When you put the bonding screw in, you made the connection to the neutral bar and the receptacles started working as they should.

Get that neutral off of that ground bar and put it where it belongs !!!! :)


JAP>
 
retirede said:
Then how would the installation of the bonding screw in the sub panel cause any change in operation?
Click to expand...

He only had 2 wires feeding the subpanel.

A hot and a neutral.

Either the neutral feeding the sub panel was landed on the neutral bar which was insulated from the panel enclosure itself, or, the neutral that was feeding the subpanel was accidently landed on the ground bar that was attached to the panel.

Either way, there was no connection at that time between the Neutral and the Ground Bar in the subpanel.

When he landed the neutrals coming from the GFI Receptacles, evidently, they weren't landed on the same bar as the feeder neutral to the subpanel, therefore, power was going to the GFI Receptacles, but, they couldn't reset because they had no Neutral return path.

When he installed the bonding jumper between the neutral and ground bar at the subpanel, then the return path was complete, and, the GFI receptacles reset.

Although still not as it should be, it allowed the GFI to reset.

JAP>
 
jap said:
He only had 2 wires feeding the subpanel.

A hot and a neutral.

Either the neutral feeding the sub panel was landed on the neutral bar which was insulated from the panel enclosure itself, or, the neutral that was feeding the subpanel was accidently landed on the ground bar that was attached to the panel.

Either way, there was no connection at that time between the Neutral and the Ground Bar in the subpanel.

When he landed the neutrals coming from the GFI Receptacles, evidently, they weren't landed on the same bar as the feeder neutral to the subpanel, therefore, power was going to the GFI Receptacles, but, they couldn't reset because they had no Neutral return path.

When he installed the bonding jumper between the neutral and ground bar at the subpanel, then the return path was complete, and, the GFI receptacles reset.

Although still not as it should be, it allowed the GFI to reset.

JAP>
Click to expand...

Got it - for some reason, it just didn’t compute in my old brain.
 
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