GFCI outlet for pool lights keeps tripping

Did you try various combinations of two lights to see if you can identify one light that causes a trip with the other two lights?

If you have lights A, B & C. Connect:

  1. A & B
  2. A & C
  3. B & C
If 1 works and 2 & 3 trip the GFCI then C is the bad light.

If 2 works and 1 & 3 trip the GFCI then B is the bad light.

If 3 works and 1 & 2 trip the GFCI then A is the bad light.
 
Did you try various combinations of two lights to see if you can identify one light that causes a trip with the other two lights?
Yes, in one of my above posts, that is a test that I ran. I did all three combinations of two lights, leaving them on for a couple minutes, and all three combinations worked fine. I was hoping that one set of two lights would trip it, letting me know which was the problem light.
 
Two lights on one GFCI - semi OK. Three on one GFCI - never been a good idea, no matter how well it may have worked in the past. Installing an LED type bulb can introduce "noise" that can cause nuisance tripping, especially if there is more than one on the circuit. Likely you have a 15a GFCI installed. With the normal 500w bulbs installed in pool lights, if all three were on, you were at the threshold of tripping just on amperage.

A very common installation is what is seen in this instance. Pool codes usually call for a "convenience" outlet at the pool equipment. It must be GFCI protected. Pool lights must also be GFCI protected. Builders usually use the same device for both applications to save money on material and installation costs. I have never understood how this passes inspections as the NEC says that they are to be on separate circuits. Out of the thousands of pools I have worked on over the years, except for commercial pools, I may have seen it done correctly 5 or 6 times.
 
Is there any good way to test/troubleshoot which set of wires, light fixture, or bulb could be the issue without having the light fixtures out of the pool?

Fluke makes a Leakage Current Clamp Meter. I have not used it.



Diagnosing GFCI trips​

Start by measuring the leakage current and then identify the source. Use a leakage current clamp meter to make these measurements. Leakage current clamp meters are similar to clamp meters used for measuring load currents; however, leakage current clamp meters perform much better when measuring current below 5 mA.
Test single-phase circuits by clamping the phase and neutral conductors. Test three-phase circuits by clamping around all phase conductors. If a neutral is present, clamp it too. The measured value will be any current flowing to ground. To measure the total leakage flowing to the intended ground connection, place the clamp around the ground conductor.

Measure the leakage current on each leg of the circuit to identify which one has considerably more leakage than the others. If one leg has a suspiciously high leakage current, ensure that the equipment is operating properly. Remember that surge suppression filters and capacitors on the power input of some electronic equipment can increase the overall circuit capacitance, which can increase leakage current. Determine loaded circuit leg leakage with the equipment "on"—switching the equipment "off" allows you to determine just the circuit wiring leakage.

If equipment on all legs is operating properly and the wiring is acceptable, it could be that the cumulative leakage current due to electronic equipment input filtering is just high enough to trigger the random GFCI tripping. In this case, consider redistributing the load on each circuit leg or adding circuits to provide more capacity.
 
Two lights on one GFCI - semi OK. Three on one GFCI - never been a good idea, no matter how well it may have worked in the past. Installing an LED type bulb can introduce "noise" that can cause nuisance tripping, especially if there is more than one on the circuit. Likely you have a 15a GFCI installed. With the normal 500w bulbs installed in pool lights, if all three were on, you were at the threshold of tripping just on amperage.

A very common installation is what is seen in this instance. Pool codes usually call for a "convenience" outlet at the pool equipment. It must be GFCI protected. Pool lights must also be GFCI protected. Builders usually use the same device for both applications to save money on material and installation costs. I have never understood how this passes inspections as the NEC says that they are to be on separate circuits. Out of the thousands of pools I have worked on over the years, except for commercial pools, I may have seen it done correctly 5 or 6 times.
I like this explanation better than mine, and it'll be a lot cheaper that swapping in new bulbs and/or cables! So @1poolman1, NEC wants each individual light on its own dedicated GFCI circuit?

@pcm2a, if you can figure out where to put 'em (two more GFCI outlets, or breakers), that might be the way to go. I'd feel a little uneasy if the actual problem is a current leak, but if it's LED noise, or just a matter of pushing that one GFCI's current rating too far, then if splitting up the lights to independent GFCIs solves the problem, that seems OK to me.

Are there inline GFCI devices that could go in that junction box?
 
Seems like something along these lines might work:


Did you say the blower is GFCI protected? Maybe leave that on the existing GFCI outlet, then install three inline GFCI units, one for each light?
 
Did you say the blower is GFCI protected? Maybe leave that on the existing GFCI outlet, then install three inline GFCI units, one for each light?
Blower is not. There is only one GFCI outlet currently, with the lights running through it.

Originally there were three flood light bulbs in there. Still all together through the single GFCI. I replaced them with the LED bulbs.

Wiring up two or more GFCI would require some changes to the configuration. Right now it goes breaker -> GFCI -> relay -> lights. There are only two wires going from the controller to the junction box, so two is the maximum if the GFCI are with the pool controller. If I bypass the GFCI then at the junction box could be 2 or 3 gfci outlets.

Will look into the leakage tests. Replacing one bulb seems a lot easier than electrical reconfiguration, even if it is the least recommended plan.
 
I like this explanation better than mine, and it'll be a lot cheaper that swapping in new bulbs and/or cables! So @1poolman1, NEC wants each individual light on its own dedicated GFCI circuit?

@pcm2a, if you can figure out where to put 'em (two more GFCI outlets, or breakers), that might be the way to go. I'd feel a little uneasy if the actual problem is a current leak, but if it's LED noise, or just a matter of pushing that one GFCI's current rating too far, then if splitting up the lights to independent GFCIs solves the problem, that seems OK to me.

Are there inline GFCI devices that could go in that junction box?
NEC wants your light circuit to be separate from the convenience outlet. The actual wording used to indicate that either a ground-fault circuit breaker or a blank-front GFCI would be the device for the light circuit with a separate GFCI (breaker or outlet) for the convenience outlet. The best option has always been one GFCI per light, but I have only seen that a handful of times. Even then, the builder usually used one of them as the convenience outlet, it just costs less to do it that way. Virtually every time I have seen 3 lights on on device there have been issues.
 
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What is a convenience outlet? The gfci that is in there is a blank on the front, with only controls to reset/test it. It would be ridiculously more convenient if that was a gfci with plugs on it, because I'm all the time running an extension cord around there!
 
A "convenience" outlet is to eliminate what you are having to do. Code here in California used to (and may still) require one in addition to the light circuit, I haven't checked in many years. Since I could only see the back of the GFCI, and 99% of the time builders use the less expensive outlet (blank-fronts cost more), I thought that is what you had (yeah, I assumed). And, you may have a 20a rated one at that. That being the case, a separate GFCI for each fixture would seem to be the best option, though not necessarily the easiest. It would require re-wiring to each j-box and light. I've done it a few times. Sometimes easy, sometimes not so much.
 

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NEC 680.22 Required Receptacle Location. At least one 15A or 20A, 125V receptacle must be located not less than 6 ft and not more than 20 ft from the inside wall of a permanently installed pool. This receptacle must be located not more than 6½ ft above the floor, platform, or grade level serving the permanently installed pool.

15A and 20A, 125V receptacles located within 20 ft from the inside walls of a permanently installed pool must be GFCI protected.
 
NEC 680.22 Required Receptacle Location. At least one 15A or 20A, 125V receptacle must be located not less than 6 ft and not more than 20 ft from the inside wall of a permanently installed pool. This receptacle must be located not more than 6½ ft above the floor, platform, or grade level serving the permanently installed pool.

15A and 20A, 125V receptacles located within 20 ft from the inside walls of a permanently installed pool must be GFCI protected.
Is this rule for the pool lights, or just plugs around a pool in general? I have four outlets that are all outdoors and within 6-20 feet of the pool. They are all GFCI protected outlets.

The gfci outlet for my pool lights is with my pool equipment and is farther than 20 feet.

A "convenience" outlet is to eliminate what you are having to do. Code here in California used to (and may still) require one in addition to the light circuit, I haven't checked in many years. Since I could only see the back of the GFCI, and 99% of the time builders use the less expensive outlet (blank-fronts cost more), I thought that is what you had (yeah, I assumed). And, you may have a 20a rated one at that. That being the case, a separate GFCI for each fixture would seem to be the best option, though not necessarily the easiest. It would require re-wiring to each j-box and light. I've done it a few times. Sometimes easy, sometimes not so much.
It's a 20a blank. When I saw the price of the blanks I wondered why they didn't use a regular gfci outlet with plugs, I'm cheap.
 
NEC 680.22 Required Receptacle Location. At least one 15A or 20A, 125V receptacle must be located not less than 6 ft and not more than 20 ft from the inside wall of a permanently installed pool. This receptacle must be located not more than 6½ ft above the floor, platform, or grade level serving the permanently installed pool.

15A and 20A, 125V receptacles located within 20 ft from the inside walls of a permanently installed pool must be GFCI protected.
There ya' go. Most builders will give one or the other (as in pcm2a's case) but seldom both unless it is a commercial pool. Most residential inspectors that I have had occasion to work with only do a very cursory inspection, as in "Looks good to me." I had one sign off a complete replacement of all residential pool equipment, including electrical panels, breakers, etc. by walking in and asking, "Where's the permit?" signing it and leaving. Asked him if he was going to look at the pool work and he said, " No, I trust you." I knew the work would pass anyway, but tried to talk the owner out of spending the permit fee as I had seen this before. Commercial properties, because of liability issues no doubt, get a better looking at.
 
Is this rule for the pool lights, or just plugs around a pool in general? I have four outlets that are all outdoors and within 6-20 feet of the pool. They are all GFCI protected outlets.
Pools in general.

Your pool conforms to NEC 680.22 due to those other GFCI outlets.
 
Is this rule for the pool lights, or just plugs around a pool in general? I have four outlets that are all outdoors and within 6-20 feet of the pool. They are all GFCI protected outlets.

The gfci outlet for my pool lights is with my pool equipment and is farther than 20 feet.


It's a 20a blank. When I saw the price of the blanks I wondered why they didn't use a regular gfci outlet with plugs, I'm cheap.
Not sure if your local code would require anything more than what you have (they can be more strict at times), but it would seem that your outlets would meet the NEC.
 
NEC 680.22 Required Receptacle Location. At least one 15A or 20A, 125V receptacle must be located not less than 6 ft and not more than 20 ft from the inside wall of a permanently installed pool. This receptacle must be located not more than 6½ ft above the floor, platform, or grade level serving the permanently installed pool.

15A and 20A, 125V receptacles located within 20 ft from the inside walls of a permanently installed pool must be GFCI protected.
This is not a service plug. A service plug must be installed within 25’ of the equipment.
 
This is not a service plug. A service plug must be installed within 25’ of the equipment.

What is not a service plug?

How is what you said different then what I posted? "At least one 15A or 20A, 125V receptacle must be located not less than 6 ft and not more than 20 ft from the inside wall of a permanently installed pool."
 
LED lights will live happily on a gfci. A gfci is not overcurrent, but measures power coming in and compares it to power returning. If less power returns, it will trip. I would check to make sure all your neutral (white) wires going to the light are connected to the load side of your deadfront gfci.
 
What is not a service plug?

How is what you said different then what I posted? "At least one 15A or 20A, 125V receptacle must be located not less than 6 ft and not more than 20 ft from the inside wall of a permanently installed pool."
That is a convenience outlet, not a service plug. It keeps people from running extension cords around the pool. The service plug needs to be within 25’ of the equipment for servicing it. Two completely different plugs. They can be one in the same if it is within 20’ of the pool and 25’ of the equipment.
 
That is a convenience outlet, not a service plug. It keeps people from running extension cords around the pool. The service plug needs to be within 25’ of the equipment for servicing it. Two completely different plugs. They can be one in the same if it is within 20’ of the pool and 25’ of the equipment.

What NEC section requires the service plug within 25'?
 

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