Need some help troubleshooting my 50A GFI breaker...

Hey guys...need some help. I will try to be as short as possible but here is my situation....

I am wiring up my control panel (used PJ's print). I put in a 50amp GFCI breaker at the main panel that is wired to a 4 prong plug on the other side of my basement. I completed all the wiring, flipped the breaker on, tested for power at the plug....everything checked out. I plug in my panel to the breaker and it instantly trips the breaker.

As part of my troubleshooting process to eliminate possible failure mechanisms I:

1) Returned Siemens 50A GFI breaker and purchased another one (thinking it may be faulty) = same result (trips immediately)

2) Took out the GFI breaker and put in a 100A breaker I had to see if the wiring in my panel was bad....PANEL WORKS PERFECTLY

So basically I need to understand why the GFI breaker is tripping and normal breaker is not. I will include pictures of my gfi wiring (which I believe is correct...and not the problem) as well as pictures of my panel and pj's print.

Thanks for any (and all) help/suggestions!

Scary as hell to me that you would choose to use a 100amp breaker to test the integrity of your wiring when you know that your 50amp breaker trips, but to each their own. I would never recommend that to someone though.

So with your 50 amp gfci breaker installed in your circuit. Have you energized your panel with all the smaller panel breaker off? If it trips your 50 amp still, check your e-stop. It may be fooling you and be closed even when you think it is open.

With all the smaller panel breakers open, if your main breaker holds. Then you can turn each one on, one at a time, and hopefully isolate the entire panel being a problem to something much smaller.

Thanks, well what made me think it may be more of a breaker problem is that with all the panel breakers off... the main GFI breaker still trips. I put in the bigger breaker just to test that my PID's would light up...and give me power. I don't have any of the elements or plugs plugged in.

And I know that the panel wiring was sound. The watched the electrian who wired it for me wire it into the panel at his house to show that it functioned appropriately...which it did. If I did not have that... I probably would not have done what I did...

Is it tripping the 50 amp breaker or the GFCI?

I apologize if I am misunderstanding what you are asking. But I only have one breaker. It is a 50amp GFCI breaker in the main panel. I do not have a standard 50 amp breaker in the main that runs to another GFI breaker in spa panel like many others have done.

The question is,which is tripping the breaker because you are drawing more than 50 amps or the GFCI because of a leak to ground?

I'm no electrician but I was hammered on a job site for plugging my extension cord into the GFIC and not direct into the tool. seems they work better closer to the end use,maybe that's why they are installed closer to the spa.

If you have a VOM (volt ohm meter), I suggest you measure resistance from your two hot legs to neutral (power off of course!). You should get zero until you flip your e-stop in which case you should measure whatever grounding resistance you put in that circuit (1k or 2k) from the leg its attached to. This will verify that you do or don't have a short to neutral that is tripping the GFCI. Probably a good check for any new panel anyway. Good luck.

if neutral and ground are bonded anywhere down stream of your GFCI this will cause it to trip.

A GFCI essentially trips when there is a difference in current between the hot legs and neutral.

Also, using a 100A breaker to test functionality is fine. If a circuit was a dead short, it would trip a 100A immediately as well. If it was pulling more than 50 but less than 100, it would take a short while to heat up enough to trip, and would not immediately trip the 50A GFCI, as it was doing.

The reason the GFCI breaker is tripping while a non-GFCI breaker doesn't is because the GFCI breaker is sensing what it believes is ground fault. A mis-match of the instantaneous current draw and return.

Attempt to isolate the part of the control panel circuit that is creating the "ground fault".
Turn off all of the breakers in the control panel and turn on GFCI breaker.
If the GFCI doesn't trip then test the functionality of the e-stop at this point.
If it works, reset the GFCI and continue to turn on one breaker at a time until the GFCI breaker trips to find the circuit leaking current.

rudylyon57 said:

If you have a VOM (volt ohm meter), I suggest you measure resistance from your two hot legs to neutral (power off of course!). You should get zero until you flip your e-stop in which case you should measure whatever grounding resistance you put in that circuit (1k or 2k) from the leg its attached to. This will verify that you do or don't have a short to neutral that is tripping the GFCI. Probably a good check for any new panel anyway. Good luck.

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My apologies, I meant to say check resistances to ground, not neutral.

The one thing I did not mention is that there is one deviation from the print I posted. It is hard to see just looking at the actual wiring... but I do not have an E-STOP wired in to the panel. Just the main shutoff

You need to be looking for a short or low resistance between ground and neutral.

Are you certain that you are wiring the GFCI breaker properly? If the neutral is not wired properly it will trip every time. Do you have a picture showing that?

You are close. We use GFI breakers on individual devices for a reason. I've done electrical controls for 20 years and you can't encompass a system like that. The electrical controls all use ground as a basis for low voltage regulators.(small cylinders that make low voltages).Dont use a gfi on a heater coil it will burn up quickly.dont use a gfi on a controller. do use a gfi where you plug something in.

Hey jeffmeh...take a peak at the picture I posted on first post showing the breaker wiring. I believe it is all accurate...but I would be happy to be wrong in this case. I have the ground and neutral on the bar right next to each other, which I believe is appropriate, but could be wrong...?

jeffmeh said:

Are you certain that you are wiring the GFCI breaker properly? If the neutral is not wired properly it will trip every time. Do you have a picture showing that?

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Hey jeffmeh...take a peak at the picture I posted on first post showing the breaker wiring. I believe it is all accurate...but I would be happy to be wrong in this case. I have the ground and neutral on the bar right next to each other, which I believe is appropriate, but could be wrong...

Wiring looks fine if that is the main panel. The VOM is the best way to find what is wrong.

Would anyone be willing to explain the best way to test with a VOM...to clarify what I am doing (wrong)

Before testing with s meter, can you take a couple close ups of the terminal blocks next to the breakers?

neild5 said:

Before testing with s meter, can you take a couple close ups of the terminal blocks next to the breakers?

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Is this what you are asking about? Appreciate the help

awarner322 said:

Is this what you are asking about? Appreciate the help

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Bottom photo - what is entering/leaving the panel with 4 wires? Nothing should be 4 wire after the main power entry.

pablosbrewing said:

Bottom photo - what is entering/leaving the panel with 4 wires? Nothing should be 4 wire after the main power entry.

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That is the wiring that goes to the 2 outlets where the pumps will be connected. Can you see it in this picture?

awarner322 said:

That is the wiring that goes to the 2 outlets where the pumps will be connected. Can you see it in this picture?

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OK - I see it. If this was wired by an electrician like you mentioned earlier, I do not know why he thought it was OK to mix wire colors. If you start out with L1=black, L2=red you want to stick to that for the entire build so you can diagnose problems later.

Start with the panel uplugged from the power source and check with an ohm meter:

• neutral wire to ground wire (should be open)
• neutral wire to case (should be open)
• ground wire to case (should be a few Ohms at most) - if missing this would not trip GFCI but the connection needs to be there to protect you.

pablosbrewing said:

OK - I see it. If this was wired by an electrician like you mentioned earlier, I do not know why he thought it was OK to mix wire colors. If you start out with L1=black, L2=red you want to stick to that for the entire build so you can diagnose problems later.

Start with the panel uplugged from the power source and check with an ohm meter:

• neutral wire to ground wire (should be open)
• neutral wire to case (should be open)
• ground wire to case (should be a few Ohms at most) - if missing this would not trip GFCI but the connection needs to be there to protect you.

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To clarify, you mean test at the house panel/breaker? And by case you mean...?

Thanks

These tests are to be done with your control panel unplugged and start testing at the plug. You do not want the brewery control panel hard wired to your house main panel

awarner322 said:

To clarify, you mean test at the house panel/breaker? And by case you mean...?

Thanks

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Those tests need to be done on your brew panel and its metal case when disconnected from main power.

pablosbrewing said:

OK - I see it. If this was wired by an electrician like you mentioned earlier, I do not know why he thought it was OK to mix wire colors. If you start out with L1=black, L2=red you want to stick to that for the entire build so you can diagnose problems later.

Start with the panel uplugged from the power source and check with an ohm meter:

• neutral wire to ground wire (should be open)
• neutral wire to case (should be open)
• ground wire to case (should be a few Ohms at most) - if missing this would not trip GFCI but the connection needs to be there to protect you.

Click to expand...

neutral wire to ground wire....giving me a reading of 2 ohms

neutral wire to case 1 ohm

ground wire to case 1 ohm

I'm assuming the neutral and ground not being open is my problem?

Your right. The neutral and ground being bonded together in your brew controller is causing the problem.

You just need to find the point where that is happening and sever that point making sure that grounds all remain together, and the neutrals all remain together.

Facinerous said:

Your right. The neutral and ground being bonded together in your brew controller is causing the problem.

You just need to find the point where that is happening and sever that point making sure that grounds all remain together, and the neutrals all remain together.

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Ok thanks. So from an education standpoint...why does a standard breaker not trip in this situation? Because the gfi is built to detect such a small amount of current between the two and standard breaker is not that sensitive?

awarner322 said:

Ok thanks. So from an education standpoint...why does a standard breaker not trip in this situation? Because the gfi is built to detect such a small amount of current between the two and standard breaker is not that sensitive?

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Layman's explanation. You are not drawing more amps than the breaker's rating, so it will not trip. You do have current leaking to your ground, rather than flowing through your neutral, so the GFCI detects that imbalance in the H H N and trips.

I suggest you open the main power plug, the two element receptacles, and the two pump receptacles and check for a neutral/ground connection. With the panel unplugged, of course.

Those locations appear to be the only place a neutral/ground connections could take place. If there are others, take a look there also.

awarner322 said:

Ok thanks. So from an education standpoint...why does a standard breaker not trip in this situation? Because the gfi is built to detect such a small amount of current between the two and standard breaker is not that sensitive?

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A gfci protection circuit trips when it sees a difference in current between the hot leg(s) and neutral. If all is well, all the current flowing through the hot leg(s) will also be flowing through the neutral. If there is less current on neutral than hot, then some current is going some place it shouldn't be, presumably through you. The gfci trips.

If ground and neutral are bonded down stream of the gfci, naturally some current will be returning via ground. The gfci sees less current than it expects on neutral, and it trips.

A regular breaker only trips if there is to much current flowing through the hot legs. It is intended to limit current based on how much the wire can handle without damage (fire).

Gfci doesn't care about over current, just that the current is going where it ia supposed to.

flatulentfox said:

If all is well, all the current flowing through the hot leg(s) will also be flowing through the neutral. If there is less current on neutral than hot, then some current is going some place it shouldn't be, presumably through you. The gfci trips.

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Not quite. In the case of a 220V heater connected between the phases the current on the neutral is 0 which is much less than the current on the hot. The missing element in your explanation is that current has a sign attached to it. In a GFCI three wires pass through a doughnut. Picture the wires (Red, Black, White) as running from left to right with the plane of the doughnut perpendicular to the paper (screen) and the load on the right. The doughnut has a coil wound around it and this coil detects the sum of the currents flowing in the three wires. Current flowing from left to right is positive and current flowing from right to left is negative. Thus in the heater example say 10 amps flows from left to right i.e. from the source to the load on the red wire. If all the return current (from right to left; load back to source) is on the black wire the algebraic sum of the currents is +10 + (-10) = 0 and the device doesn't trip. The neutral wire carries no current in this case. If any hot leg current from source to load returns though a path other than the other hot leg wire OR the neutral then the return current does not cancel the forward current through the doughnut and the coil senses this tripping the mechanism.

The correct description of the functioning of a gfci is that it will trip if the algebraic sum of the currents through it is different from 0 by a threshold amount or, in non mathematical terms, if all the current flowing from source to load (on any wire(s) through the doughnut) is not nearly equal to the current returning from the load to the source over any one or combination of the other wires passing through the doughnut. Or perhaps by saying that all the current that goes to a load through the GFCI must return through the GFCI.

That is a very good explanation of how gfcis work ajdelange.

Great. So let's apply it to the problem at hand. Referring to the picture in #1: If the wires (red, black, white) are pulled off the breaker busbar in the panel then a meter should read open circuit between any of them and the bare wire. Finite impedance between the bare wire (which does not go through the GFCI) and any of the other wires means that some current can flow back to the panel through the bare wire (grounding conductor) thus the GFCI will trip.

awarner322 said:

neutral wire to ground wire....giving me a reading of 2 ohms

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That seems to be the case here. Find that bridge and the problem will be solved.

But that isn't really why I posted here. I noticed in the last photo in #1 that grounding conductors (bare) and grounded conductors (white, neutral) are terminated in the same bus bar. I have never seen that before. All the panels I've ever seen (and I've seen a few but I'm not an electrician) have separate bars for these and those two bars are bonded if the panel is the service entrance and isolated if it is not. This would be kosher if this panel is the service entrance (and I can't see if there is a main breaker as it would be off to the left in this picture) but if it is a sub panel or the service equipment is in a separate box it is not. Just something I noticed. This would not effect the operation of the GFCI.

ajdelange said:

....... I noticed in the last photo in #1 that grounding conductors (bare) and grounded conductors (white, neutral) are terminated in the same bus bar. I have never seen that before. All the panels I've ever seen (and I've seen a few but I'm not an electrician) have separate bars for these and those two bars are bonded if the panel is the service entrance and isolated if it is not. This would be kosher if this panel is the service entrance (and I can't see if there is a main breaker as it would be off to the left in this picture) but if it is a sub panel or the service equipment is in a separate box it is not. Just something I noticed. This would not effect the operation of the GFCI.

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I'm not an electrician either, but did summer work for one many years ago. It's common practice in the main panel where the bus bars are bonded together. It results in a cleaner install. Neutral and ground conductors can be routed together with, and terminated very near, the hot conductor(s) instead of separately routed.

Maybe it is a local code thing.

One compelling reason to not do it that way (i.e. to use the separate bars instead) occurred to me. This probably wouldn't apply to many but it applied to me. I decided to build a garage (well really a brewery with space to park some cars). With my 'lab' and a guest bedroom upstairs the building became large enough to require a separate panel of its own. This actually presented an opportunity to get rid of ugly overhead feed wires but the only sensible way to do this was to put the service entrance on the back of the new building and run underground feeders to the existing panels. Had these not been wired with earth and neutral connected to separate busses they both would have had to be rewired which while doable would certainly been a PITA (expensive) and probably wound up as a mess of wire nuts.

Sorry for such a long delay in response. First off, thank you for all the input...I have a much better understanding for ground fault circuits now.

My problem was a very stupid one...that I was easily able to figure out once I understood why the breaker was tripping only with gfi and not a normal breaker. If you can see it in my first picture... I have the 30amp wire pigtails coming off the side of the box with female plugs on them. These are 3 pole plugs where I bonded the ground and neutral together...which is the (now obvious reason) I was having problems. I will be off to the store to buy 30 amp-4 wire friendly receptacle/plugs now...

These 30A pigtails are running to the kettle elements, correct?

In the wiring diagram there's no neutral running to the elements, and you don't actually need a neutral to the elements, I think. So you can use 3-wire plugs and receptacles to run HHG to the elements, just break the link between neutral and ground in the pigtails.