Help with park gfci breakers popping

[dznf0g]

New problem, and to be honest I've never really paid a lot of attention to park posts with or without gfci breakers. Here's the issue:
I am in the second of two Illinois state parks. The first was a 30 amp site with a 15A duplex. Both circuits were fitted with GFCI breakers. The second is a 50A site, with a 30A and a 15A duplex. Both the 30 and 15 are fitted with a GFCI breaker. The 50A is not a GFCI Breaker.
On both sites, The GFCI breakers will pop...sometimes immediately....sometimes after as much as 12 hours. Doesn't matter whether I have my EMS inline, or not. Doesn't matter if is is a 2 amp load or an 18 amp load.....leading me to believe it is a GFCI tripping event.
Both my home Non-GFCI 30 amp circuit nor this park's non-GFCI 50 amp circuit have any issue with tripping.
I have no electrified skin issue...at least detectable to the human touch.
I have read that "stacking" GFCI breakers/outlets in stick houses can create weird issues, but I am not sure how/if that applies to our trailers. If I shut off the GFCI circuit (bath and kitchen outlets) in the AS, it would still pop the GFCI 30 amp park breaker.

Questions:
1) I am not real clear how the 120 grounding system in the AS plays with park grounding. Can someone clarify that for me?
2) I understand that GFCI need to see only a very small mA leak to ground (trailer shell?) to pop. How do I test that? Ammeter probes from shell to park post body?
3) What else don't I know, or am overlooking?

[uncle_bob]

Hi

GFCI breakers are not typically a "long life" item. They can and do wear out. You may simply have run into some end of life examples.

When working correctly, they will trip on *anything* past the breaker. Spider in the plug on the post ... pop. Rain getting into the connection between the post and your trailer ... pop. Rain getting into the cables somewhere along the way between the post and you trailer (adapters, extension cords .....) ... pop.

Yes I'm focusing a bit on rain. It's been wet here for quite a while. Anything that gets water here or there can be an issue.

Lots and lots of possibilities.

Bob

[dznf0g]

Thanks Bob. A bit more info...and I did think of those items. I did have a park maintenance guy come over in Park #1 and switch out the breaker. No change. The ground is bone dry and very dusty in both campgrounds. Doesn't necessarily mean a lot though.

Is there anything in the trailer that could have changed suddenly?
Any tests I could run?

It could all be a coincidence, but I really don't put a lot of credence in these kinds of coincidences.

I did, about a year ago, check and tighten all the wires in the AS 120v box. None were really any kind of loose. I haven't ever done s service on the ground lugs to the trailer frame. Could that give a GFCI only issue?

[dznf0g]

it's a 2007 trailer with 86k miles. my cord connections appear/feel good and tight. Trailer port and cord end (trailer end) were replaced about 2 years ago and have no melting/burning appearance. EMS is less than a year old....but I eliminated that as a potential issue by removing it from the setup, with no symptom change.

[richard5933]

There are a few things which can cause a GFCI to pop like this. It's always a short to ground somewhere, and it can be something as simple as a single strand of a stranded wire which was not properly inserted into an outlet to a failing appliance or device.

Making it more difficult to troubleshoot in this case is that it from your description it sounds like it's intermittent, meaning that it's something which isn't always turned on or engaged.

One thing which comes to mind in your water heater. If there is an electric element in it for heating water from 120v, it could be failing. A failing element can cause a short to ground and it will only happen when the water is being heated. On a 2007 model trailer it would be about the right time for an element to fail, assuming that your water heater has the 120v option.

My plan of attack on this would be to eliminate things one by one, either by turning off circuits one by one trying to find the problem circuit, or by doing the same for devices one by one. Hopefully you get lucky and find it early in the process.

[dznf0g]

Originally Posted by richard5933

There are a few things which can cause a GFCI to pop like this. It's always a short to ground somewhere, and it can be something as simple as a single strand of a stranded wire which was not properly inserted into an outlet to a failing appliance or device.

Making it more difficult to troubleshoot in this case is that it from your description it sounds like it's intermittent, meaning that it's something which isn't always turned on or engaged.

One thing which comes to mind in your water heater. If there is an electric element in it for heating water from 120v, it could be failing. A failing element can cause a short to ground and it will only happen when the water is being heated. On a 2007 model trailer it would be about the right time for an element to fail, assuming that your water heater has the 120v option.

My plan of attack on this would be to eliminate things one by one, either by turning off circuits one by one trying to find the problem circuit, or by doing the same for devices one by one. Hopefully you get lucky and find it early in the process.

Some good nuggets here.....however, relative to the water heater, and as stated in post#1, it happened with a 2A draw (per PD 30X EMS readout). In other words, I had fridge on gas, water heater on gas, and only the charger active....and an LED light or two.
But, to your point. I should eliminate one circuit at a time at the AS breaker box. It is something quite intermittent....sometimes. Sometimes it'll trip immediately upon resetting. That's when I need to eliminate a circuit at a time.

[ITSNO60]

Originally Posted by dznf0g

Some good nuggets here.....however, relative to the water heater, and as stated in post#1, it happened with a 2A draw (per PD 30X EMS readout). In other words, I had fridge on gas, water heater on gas, and only the charger active....and an LED light or two.
But, to your point. I should eliminate one circuit at a time at the AS breaker box. It is something quite intermittent....sometimes. Sometimes it'll trip immediately upon resetting. That's when I need to eliminate a circuit at a time.

Just be aware that if there is a neutral to ground fault, shutting off the breaker or switch to the faulty device won't always stop the GFCI from tripping. With a N-G present in one circuit there is a path for neutral current to find it's way to the grounding conductor on every other circuit as they all share common ground and neutral connections in your panel. It won't be much when your main neutral connection is good but it only takes a tiny bit to trip the GFCI. This can lead you to a lot of tail chasing as it can make other loads and circuits look suspect when they may be fine.

This is because , contrary to the saying "electricity always takes the path of least resistance", electricity actually takes all available paths with the amount carried on each path proportional to each path's resistance.

Generally when trying to isolate a N-G fault we remove both the hot the neutral to the suspect circuit. Sometimes you'll get lucky and find some continuity between the removed neutral and the ground bus.

Seems water heater elements, absorption fridge elements and inverters are the most common culprits.

Also, a trailer with a 50 amp service connected to a 50 amp hookup with have different amounts of current on the main supply neutral depending on how each leg is loaded, it can be as little as zero if both legs are perfectly balanced, but on a 30 amp trailer the total neutral current will increase linearly with the total of the loads. Higher total neutral current present on the system means higher neutral current at any N-G fault, eventually exceeding the trip threshold of the GFCI. (this doesn't seem to apply to you though as you said the 50 is not GFCI protected)

[lemley]

As mentioned, turning off breakers is a great way to start.

I like to troubleshoot by Gaussian elimination. Break the problem in half iteratively until it is isolated. Here’s how I would do it:

1. Turn off the 30 amp main breaker. Test. If good then
2. Turn the 30 amp back on. Then turn off half of half of the 20 amp breakers. Test. If good then turn those on and turn off the other breakers.

Once you have isolated the problem circuit, I would go to the manual and see which outlets are on that circuit. Follow the same process, working half at a time.

My current issue is with my power converter. That was a surprise to me, but it seems that it is a common issue.

If all else fails, get a 50 to 30 amp dogbone.

[cedonly]

The easiest way to check is to turn off 130v breakers in your AS and turn on one by one and wait a reasonable amount of time. I would suspect 3 issues 1. Refrigerator temp sensor 2 water heater elec. not grounded properly (I had this issue from the factory) 3. Inverter not playing nice..

You will never feel any issue at the level of tripping a gfci and measurement is beyond this discussion thread. A/b testing is the way to go

Originally Posted by dznf0g

New problem, and to be



honest I've never really paid a lot of attention to park posts with or without gfci breakers. Here's the issue:
I am in the second of two Illinois state parks. The first was a 30 amp site with a 15A duplex. Both circuits were fitted with GFCI breakers. The second is a 50A site, with a 30A and a 15A duplex. Both the 30 and 15 are fitted with a GFCI breaker. The 50A is not a GFCI Breaker.
On both sites, The GFCI breakers will pop...sometimes immediately....sometimes after as much as 12 hours. Doesn't matter whether I have my EMS inline, or not. Doesn't matter if is is a 2 amp load or an 18 amp load.....leading me to believe it is a GFCI tripping event.
Both my home Non-GFCI 30 amp circuit nor this park's non-GFCI 50 amp circuit have any issue with tripping.
I have no electrified skin issue...at least detectable to the human touch.
I have read that "stacking" GFCI breakers/outlets in stick houses can create weird issues, but I am not sure how/if that applies to our trailers. If I shut off the GFCI circuit (bath and kitchen outlets) in the AS, it would still pop the GFCI 30 amp park breaker.

Questions:
1) I am not real clear how the 120 grounding system in the AS plays with park grounding. Can someone clarify that for me?
2) I understand that GFCI need to see only a very small mA leak to ground (trailer shell?) to pop. How do I test that? Ammeter probes from shell to park post body?
3) What else don't I know, or am overlooking?

[gator.bigfoot]

The question is, is the breaker tripping on the ground fault or over current? What loads do you have running? It doesn't sound like a ground fault issue, since that would trip a lot quicker. It sounds more like you're exceeding the max current of the breaker. The 80% rule could come into effect after that length of time if you're on the edge. If you're not even close to being on the edge, then you'd have to go back to the Grounding. Could it be an intermittent ground? How good are the connectors, do you have any frayed wires in the power cord, are the screws tight. Too many scenarios. You'd have to check them all. You need to eliminate them all.

If you've done all that and it still trips. Then start to turn off circuits in the trailer. You may run out of time before you figure it out. I've got a 30 amp plug next to my house which I occasionally plug the trailer into. Maybe you gave the same. Just switch out the regular breaker for a gfci and see what you get.

Best of luck.

[edroelle]

I have had the problem in the past with some inverters causing the problem. I resolved it by carrying an ultra isolator transformer that is used to provide a clean wave form. It is in my storage garage now.

[Biglabrowdy]

Originally Posted by uncle_bob

Hi

GFCI breakers are not typically a "long life" item. They can and do wear out. You may simply have run into some end of life examples.

When working correctly, they will trip on *anything* past the breaker. Spider in the plug on the post ... pop. Rain getting into the connection between the post and your trailer ... pop. Rain getting into the cables somewhere along the way between the post and you trailer (adapters, extension cords .....) ... pop.

Yes I'm focusing a bit on rain. It's been wet here for quite a while. Anything that gets water here or there can be an issue.

Lots and lots of possibilities.

Bob

Bob any spark type Device will cause a GFCI to trip. I have GFCI breakers and ANY time I use my Table Saw it
trips the breaker because it is a spark type Motor start (Brushes). Most Electricians state it is Normal due to the Spark type issue. They are designed to detect any spark in the circuit. Something to consider or look for.

[Engineer_Jud]

Disclaimer: I am a licensed professional electrical engineer. I am giving my account of my personal experience. This is not advice for how to handle your specific issue.

Same problem for me. When trying to power my 2022 Globetrotter 27FB from F250 Propower 2kw inverter, the truck senses a ground fault and shuts off. My AS has a WFCO WF-8930/50 load center that has an integral receptacle on the back of it. The factory converter (WF-9855LiS) is plugged into this receptacle. The receptacle is wired to a 15-amp circuit breaker in the panel. However there is what seems to be a Ground Fault sensor integrated in the panel, but only for this circuit. I reached out to WFCo support to inquire about the purpose of this device, but got not response.

I isolated the problem to this circuit. When I opened the 15a converter breaker, the truck inverter powered the rig fine. When I closed the breaker, immediately tripped GF. (Note I had no issues when powering from a GFCI receptacle in my garage under similar test).

So, I unplugged the 9855 converter from the receptacle and plugged it into an extension cord plugged directly into the truck pro-power inverter receptacle. Guess what? Yep, Worked fine.

Therefore, issue is the GF sensor integrated into the WFCo panel causes the very sensitive truck inverter to trip on GF.

Solution - I disconnected the integral receptacle on the WFCo panel and wired a new one (I used the receptacle end of a 14 gauge extension cord with an 18” pigtail landed directly on the CB and neutral bus). Plugged the converter into that. Put it back together. Problem solved. All GFCI receptacles in the trailer still work, regardless of the power source. The converter receptacle no longer has GFCI protection but that’s ok and is not an NEC code violation to my knowledge.

Just a little more info:

1) the pro-power inverter in the F250 is bonded (bonds N-G when it is producing 120v AC power). It is not a floating neutral inverter. However, the system is not “earth grounded” when you are running the inverter to power the rig. This is okay, it just means there is no return path for a ground fault “through the earth”. There is still a return path through the metal frame of the truck/trailer, and the equipment grounding conductor in the shore power cord plugged into the truck inverter. Also, the GFCI on the truck can still sense a GF without an earth return path.

2) the inverter onboard the AS (whether factory or aftermarket) will have a N-G bond relay that bonds N to G only when it is running off battery. When the inverter has AC input power from any source, it breaks the N-G bond. There can only be one N-G bond in any system. If the batteries are the source, the N-G bond is at the inverter output. If the shore power is the source, the inverter is in bypass mode and the N-G bond is at the source service panel (at the campground or your house panel). If the source is a portable generator, as far as the inverter goes it is the same as shore power. But the portable generator must be a bonded generator for the GFCI to function properly. The F250 pro power is a bonded inverter (I believe - need to confirm) so if that is the source, the N-G bond is at the truck inverter.

Hope this helps. I’ve read a lot of “GFCI trips on pro-power inverter” concerns but haven’t seen anyone with this solution so thought I would share. I don’t advise disabling your N-G relay on your inverter. There’s usually a better way that is safer.