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07-13-2008, 09:11 PM   #16
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Quote:
 Originally Posted by Speedy Petey The neutral will carry all the imbalance and it should still not trip. Here is a VERY simplistic example: Leg "A&B" 2p20 carrying 15A - spaces 1&3 2p20 carrying 10A - spaces 2&4 Leg "A" sp20 carrying 5a - space 5 sp20 carrying 5A - space 6 Leg "A" sees 35A Leg "B" sees 25A The neutral sees 10A Any imbalance in this scenario, such as the neutral seeing less than 10A, or leg "A" seeing less than 35A would mean there is a ground fault somewhere.
Peter (nod to P. Abernathy),

Nice, simple but great example.

The 2p breaker example seems even more like a 3ph residual GF scheme. The load at the other end of the feeder is never balanced (except in university textbooks). But as long as the planets align properly and all the electrical charge stays within the walls of the cable jackets, all is well magnetically inside that little torroid. And the 51G relay smiles down upon us!

TTFN,
Jimbobaroooney

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 07-13-2008, 09:44 PM #17 Newbie   Join Date: Jul 2008 Posts: 11 Rewards Points: 10 BigJimmy: Not being that electric savy it took me a few minutes to digest that one. First, there are two black wires and a green going to the sub. The green wire is clamped to a ground wire going to the grounding bus and the black ones are of course connected to the breaker. I simply conected the black wires to the gf and the white pig tail to the neutral bus. After thinking about it, I believe there was a white wire going out to the sub too. There just about has to be, Right? If I were supposed to connect the white neutral to the gf, I did not. I will look at it again tomorrow and let you know. Thanks! Ignorance is bliss Last edited by rivers; 07-13-2008 at 09:58 PM.
07-14-2008, 03:49 AM   #18
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Quote:
 Originally Posted by rivers BigJimmy: First, there are two black wires and a green going to the sub. The green wire is clamped to a ground wire going to the grounding bus and the black ones are of course connected to the breaker

Is there a white wire { netural } in the subpanel ??

If not that why the GFCI will trip every time you hit the 120 v circuit on.

Merci,Marc

07-14-2008, 07:02 AM   #19
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Quote:
 Originally Posted by rivers After thinking about it, I believe there was a white wire going out to the sub too. There just about has to be, Right?
YES! Unless the sub was wired by Homer Simpson, there had better be a neutral but here's something to consider. Feeder cabling, due to its size, is often all the same color (usu. black jacket). What you may have is one black jacketed conductor with white tape on its end to identify it as being a neutral. If the electrician didn't do that, you can still tell as it will be terminated on the neutral bus.

Keep us informed.
Jimmy

PS: The like colors of the individual conductors is more of a reality when the installation is loose conductors in pipe. If this is some form of multiconductor cable, chances are that you will indeed have a white jacketed wire. Didn't mean to confuse the issue not knowing what type of materials you have.
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Last edited by BigJimmy; 07-14-2008 at 08:52 AM.

 07-14-2008, 09:55 PM #20 Newbie   Join Date: Jul 2008 Posts: 11 Rewards Points: 10 Me again: Getting home late tonight. I located that neutral wire and hooked it up above the pig tail and wired the tail to the neurtal bus and it still tripped. Could it be that there is simply too much on the sub panel? It is a 40 amp double pole feeding the sub. On the sub there is 2 20 amp doubles and 4 20 amp singles. Only two 20s are actually used however. Any thoughts?
07-14-2008, 10:12 PM   #21
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Quote:
 Originally Posted by rivers Me again: Getting home late tonight. I located that neutral wire and hooked it up above the pig tail and wired the tail to the neurtal bus and it still tripped. Could it be that there is simply too much on the sub panel? It is a 40 amp double pole feeding the sub. On the sub there is 2 20 amp doubles and 4 20 amp singles. Only two 20s are actually used however. Any thoughts?
you need to take a picture of both panels so we can see what you did, i'm betting its a wiring error.

07-15-2008, 02:27 AM   #22

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Quote:
 The green wire is clamped to a ground wire going to the grounding bus
I think there is a strong possibility that he has an improper neutral to ground bond at the pool panel. This would answer why his 40 amp gfci still trips at the house panel afer applying Jims fix. The gfci is still seeing too little current on the neutral. It was sensing zero amps... it now is only seeing approx. 1/2 the amps it should be sensing because the other half of the return current is on the feeder equipment ground wire.

Rivers

Be sure to turn off the 40 gfci at the house sub panel before touching the pool panel metal.

If your neutrals and grounds are on the same terminal bar or your main bonding means is installed at the pool panel this is why your 40 amp DP GFCI is tripping.

07-15-2008, 09:17 AM   #23
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Quote:
 Originally Posted by Stubbie If your neutrals and grounds are on the same terminal bar or your main bonding means is installed at the pool panel this is why your 40 amp DP GFCI is tripping.
Stubbie-

Good point and I bet this is why Chris wants to see pictures of both panels. After all they are worth a thousand words.

Nice to see you pop up again, it's been a while. Hope the fish are biting!
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07-15-2008, 10:00 AM   #24

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Quote:
 Originally Posted by BigJimmy Stubbie- Good point and I bet this is why Chris wants to see pictures of both panels. After all they are worth a thousand words. Nice to see you pop up again, it's been a while. Hope the fish are biting!
Thanks Jim... glad your still here also. I'm starting to get a little more time to spend on the forum but it is usually the wee hours.

Yeah.... Chris is wanting to see how he has the feeder wired. A picture certainly would do the trick.

Fishing is bad ....... Fished a bass tourney (60 boats) Sunday. My partner and I finished 2nd and I caught the big bass..3.27 lbs. We had 2 fish to weigh .. 5.78 lbs. If that tells you anything.....

 07-16-2008, 06:14 PM #25 Newbie   Join Date: Jul 2008 Posts: 11 Rewards Points: 10 Back again: Here is a picture of the sub panel at the pool house. Please let me know if you need more information. Thanks to all! Attached Thumbnails
07-16-2008, 07:10 PM   #26
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Quote:
 Originally Posted by rivers Back again: Here is a picture of the sub panel at the pool house. Please let me know if you need more information. Thanks to all!

Need a picture of the house panel also....

In the pool panel, I cant tell but looks they they only ran 3 wires? T/F?
Looks like they did after looking at the picture longer...

Also, I dont see a GEC at the pool panel, (unrelated to your problem)

Last edited by chris75; 07-16-2008 at 07:14 PM.

 07-16-2008, 07:43 PM #27 Newbie   Join Date: Jul 2008 Posts: 11 Rewards Points: 10 Hey: There are 2 blacks, one white, and a small green which goes to the ground bus. What exactly is a GEC? Also, the white wire going to the ground bus is a ground wire coming from one of the pool pumps. Thanks Last edited by rivers; 07-16-2008 at 07:45 PM.
07-16-2008, 07:51 PM   #28
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Quote:
 Originally Posted by rivers Hey: There are 2 blacks, one white, and a small green which goes to the ground bus.
Quote:
 Originally Posted by rivers What exactly is a GEC?
Grounding Electrode Conductor, your required by code to have a Grounding Electrode System at each building or structure served. A ground rod is pretty common.

Quote:
 Originally Posted by rivers Also, the white wire going to the ground bus is a ground wire coming from one of the pool pumps. Thanks
Ya know, I pretty much figured that must be what was done... thats a violation also. just FYI...

Also, snap a few pics of the house panel, one of the entire panel and one of your install of the GFI breaker... Make sure we can see exactly what you did.

 07-16-2008, 08:49 PM #29 Newbie   Join Date: Jul 2008 Posts: 11 Rewards Points: 10 I have been reading about shared neutrals and it has even been suggested on the post as to the problem. If, indeed that all of the single 20 amp circuits in the sub panel has some sort of shared nertral would this cause all of the 20's to be suspect? Come to think of it, please explain what a shared nertral is. The two 40's worked fine with the gfi connected. Do you believe that because there is no neutral on the 40's is why they work? Would individual gfi's in the sub work or be safe??? Last edited by rivers; 07-16-2008 at 09:02 PM.
07-16-2008, 09:20 PM   #30
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I wanna see how you wired that GFI 40 amp breaker first...

Also, your positive that any one of the four single pole breakers trip the 40amp GFI and not just one?

Last edited by chris75; 07-16-2008 at 09:23 PM.

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