Neutral to Ground bond question

[Ephraim]

I have a brand new 2019 30" Classic. My storage facility gives me the ability to have what they call trickle power Which is basically a 15A 120V circuit shared between 4 RVs. The reason the storage facility does this is so that you can keep your batteries topped off AND there is enough power to generally run your refrigerator to cool it down a couple of days before your trip.

The problem I'm having is that when I plug the AS into their power, it instantly trips the GFCI breaker in the storage facility. I've narrowed the issue down to there being a bond between the neutral and ground inside the trailer somewhere.

For those that don't know, neutral and ground should be bonded at the main breaker box (at the storage facility) or at the generator. The only time they should be bonded in the trailer is when the Inverter is powering the outlets, it should bond the two together. When it's turned off it should release that bond. Most quality inverters do this automatically.

The end result is that I can't use the storage power as-is. I had the trailer in for warranty servicing about a month ago and brought this issue up with them. I don't think they grasped what was going on though. They tried four answers with me:

1. The trailer was drawing to much power and tripping the 15A breaker.
2. I don't know what I'm talking about.
3. There is nothing wrong with the trailer.
4. Airstream (Jackson Center) says there is nothing wrong with the trailer.

When I informed them that even when nothing is turned on, it trips the breaker and when all other RV's are disconnected from the power it trips the breaker, They backed off of #1. But then tried #2 on me. I pulled out my DVM and showed them that there was continuity between neutral and ground at the trailer. They still wouldn't back off of #2 though.

When they finally grasped the concept of what I was talking about, they claimed that they only had 30A and 50A outlets and couldn't test the 15A GFCI (after 4 days of negotiating). I suggested that they run an extension cord from their bathroom circuit to plug the trailer in. They then informed me that their entire facility had no CFCI breakers. I pulled up a copy of the National Electrical Code on my iPad for them (which Albuquerque and all surrounding counties have implemented to some degree) and showed them where all outlets exposed to potential water (bathrooms, kitchens, outside, etc..) had to be GFCI. They basically said that Airstream says there is nothing wrong and they won't do anything. The tech also told me to tell the storage to put in a non-GFCI outlet, which I explained was illegal. Everyone just shrugged their shoulders and walked away.

Does anyone else have this issue?

[overlander63]

For some self-help, try the following at the storage facility:
Turn off ALL the breakers in your trailer, plug in to the outlet. Verify the GFCI hasn't tripped. In a way, it would be good if it did, because that would mean the problem is within the area of the end of the power cord to the point it connects to the breaker panel.
Assuming it doesn't trip, turn on one breaker at a time until it does, which is the circuit with the problem. Check the label on the panel to see which circuit caused the trip, at least you'll know which circuit has the problem. One thing to try is to unplug the fridge from 120v, and see it that stops the problem. I've seen three trailers over the years that had leakage through the heating element which tripped the GFCI.
BTW, our shop was built before current electrical code mandated GFCI, and is grandfathered in. Your dealership may have the same thing going for it.

[Mach5]

I have this problem. To work around it, I manually trip the trailer's 120 VAC breaker that feeds the inverter and then I can plug into a GFCI protected shore power outlet. There are a few threads on this forum regarding this same issue.

[TheGreatleys]

I had this problem when I had my AC system half-wired and left a bare neutral wire touching the skin on a circuit that was switched off. Didn't think it would be a problem, and learned something about AC electrical systems.

The breaker only switches the hot side. The neutral and ground are both wired directly to the bus bar with no switching. So, if you have an actual neutral to ground fault, IT WILL NOT MATTER IF THE BREAKER IS ON OR OFF. A neutral to ground bond will trip a GFCI instantly, while a problem with a load might or might not.

Step 1 of diagnosing would be to see if you actually have a neutral to ground bond in the trailer. Unplug and test for continuity between neutral and ground on any outlet in the trailer. If you have a neutral to ground bond, that's easily demonstrated at your dealer with a multimeter.

If you don't have a neutral to ground bond in the trailer (or in your cord) then the problem is probably with one of the loads, and the advice previously given in this thread would be a good course of action.

[Ephraim]

Definitely in the inverter circuit. I can run everything in the trailer, but as soon as I turn that circuit on, even with the inverter turned off, it pops the breaker.

[Ephraim]

Just got off of the phone with the dealer again. They still claim that nothing is wrong and that Airstream's comment is "just don't plug it into a CFCI circuit."

Can anyone else confirm that this is the response from Airstream? How is this acceptable?

I'm ready to yank the WFCO inverter out (and the WFCO converter) and put a Victron Multiplus 2000 in their place.

[Bill M.]

Glad you found it. Definitely sounds like something you are going to have to fix yourself. At least you can live with it now that you know how to store it. I guess now you need to find out if it is shorted through the inverter or it is simply wired wrong in that circuit. Wired wrong is my guess from what you have said.

[Mach5]

I posted this in another thread, sorry in advance for re-posting:

From the WFCO 5110R 1000 watt inverter Operator's Manual, page 3 under General Information: (emphasis mine)

"A convenient 120 VAC power cord is attached to the WF-5110R for pass-through use. Simply plug the power cord into any standard (non-GFCI) 120 VAC receptacle."

I don't think the problem with tripping the shore power GFCI is because Airstream wired anything incorrectly. I think the problem is that Airstream supplied an inverter that is incompatible with a GFCI protected power source.

[uncle_bob]

Originally Posted by Ephraim

Definitely in the inverter circuit. I can run everything in the trailer, but as soon as I turn that circuit on, even with the inverter turned off, it pops the breaker.

Hi

Then simply shut off the circuit to the inverter when you are in storage . There is no practical reason to have that fired up while you are storing the trailer.

The output of the inverter is run through an AC switching arrangement. It's a good bet that yours isn't quite wired right. The output of the inverter should only short neutral to ground when its in the "invert" mode (if at all). I'd bet yours is mis-wired to be connected all the time.

Bob

[Mach5]

Originally Posted by Ephraim

Definitely in the inverter circuit. I can run everything in the trailer, but as soon as I turn that circuit on, even with the inverter turned off, it pops the breaker.

Just to clarify "it pops the breaker", do you mean the shore power GFCI, or the circuit breaker in your trailer's control panel that feeds the inverter circuit?

Or is your shore power receptacle on a circuit with a GFCI protected circuit breaker in your house main electrical panel? If so, is the breaker tripping, or the GFCI?

From what you described earlier, I think you meant to say "it pops the GFCI"

[Ephraim]

Originally Posted by Mach5

Just to clarify "it pops the breaker", do you mean the shore power GFCI, or the circuit breaker in your trailer's control panel that feeds the inverter circuit?

Or is your shore power receptacle on a circuit with a GFCI protected circuit breaker in your house main electrical panel? If so, is the breaker tripping, or the GFCI?

From what you described earlier, I think you meant to say "it pops the GFCI"

The GFCI is popping. At both locations, it is an actual breaker (not the outlet with the buttons) so I've just said breaker, but it is the GFCI for sure. A normal breaker does not pop when it's plugged in.

I've pretty much decided to replace both the WFCO inverter and converter with a Victron Multi-Plus 2000. I severely dented the lower body wrap between the entry stairs and curb-side wheel well when part of my driveway gave way. I'll be replacing that this Winter and when I have the damaged panel off, I'll run heavier cable to the batteries for the Inverter. That will fix two problems at once.

I'm disappointed in the WFCO equipment. it seems barely adequate in capabilities for what it needs to do.

[uncle_bob]

Originally Posted by Ephraim

The GFCI is popping. At both locations, it is an actual breaker (not the outlet with the buttons) so I've just said breaker, but it is the GFCI for sure. A normal breaker does not pop when it's plugged in.

I've pretty much decided to replace both the WFCO inverter and converter with a Victron Multi-Plus 2000. I severely dented the lower body wrap between the entry stairs and curb-side wheel well when part of my driveway gave way. I'll be replacing that this Winter and when I have the damaged panel off, I'll run heavier cable to the batteries for the Inverter. That will fix two problems at once.

I'm disappointed in the WFCO equipment. it seems barely adequate in capabilities for what it needs to do.

Hi

You will need to run a pair of cables up in the 4/0 range to really do right by the multi according to the Victron manual. I can't see it ever needing anything that bulky but that's what the manual says.

It's probably worth running a control cable over under the sofa at the same time.

Bob

[TheGreatleys]

Originally Posted by Ephraim

barely adequate

Factory Equipment: noun 1. Barely adequate

[Ephraim]

Originally Posted by uncle_bob

Hi

Then simply shut off the circuit to the inverter when you are in storage . There is no practical reason to have that fired up while you are storing the trailer.

Bob

Our storage facility allows us to work on the trailer while it is there. It's not uncommon for the wife to meet me there to eat lunch when I'm working on it. We often watch TV while eating.

[Hein]

If neutral is bonded in two places (host and trailer) then current will flow along the ground wire between them. The GFI on the host system is detecting the leakage and tripping. If the host is not GFI then you could have a hot skin condition. Definitely a safety issue to be avoided.

I am not electrician but that is my understanding. Please correct me if I am wrong.

All the best,
Hein

[uncle_bob]

Originally Posted by Ephraim

Our storage facility allows us to work on the trailer while it is there. It's not uncommon for the wife to meet me there to eat lunch when I'm working on it. We often watch TV while eating.

Hi

Ok if turning it off is not an answer then dig deeper.

1) Pull the circuit off the output of the inverter and see if things still trip (yes, pull it off when all the circuits are dead and then try it l...).

2) If it still trips, it's the inverter, replace it.

3) If it does not still trip then it's the circuit(s) on the output of the inverter. Check them one at a time.

Bob

[Ephraim]

Originally Posted by uncle_bob

Hi

Ok if turning it off is not an answer then dig deeper.

1) Pull the circuit off the output of the inverter and see if things still trip (yes, pull it off when all the circuits are dead and then try it l...).

2) If it still trips, it's the inverter, replace it.

3) If it does not still trip then it's the circuit(s) on the output of the inverter. Check them one at a time.

Bob

Yeah, it's the inverter. I'll just have to deal with it until I can replace it this winter. The invert says not to plug into a GCFI outlet so WFCO knows this is an issue in their inverter. I'm not going to fight them. The long range plan is to combine the inverter and converter into a Victron Multi-Plus. That will give me the ability to actually run the Microwave (at the wifes request. I'll have to rewire the AC panel, but that's OK.

That will also give me more room under the closet where I can beef up the solar. I'm hoping to get 1000W on the roof, but that will depend on the solar panels I choose. I'll be using victron there as well. I will probably put in an option for external solar panels as well.

Now, where to put all those batteries... Under the couch is pretty limited. I might be able to stuff close to 400AH of LiPo under there, but am not sure.

[uncle_bob]

Hi

Ok, I have a Multi 2000. If wired properly (heavy enough cable) it will indeed run the microwave. To make that "reasonable" you really need a separate sub panel for the output *or* you have a whole lot of "stuff" on one breaker. ( = the breaker that runs things when the inverter is off). The transfer switch in the Multi will handle 50A so you can indeed get pretty crazy with the sub panel. The 2000 will (with a bit of surgery) fit where the stock inverter is mounted. The 3000 is better in the bang for the buck department, but a bit larger.

1,000W worth of panels on the roof of a 30' Classic is stretching things a bit. It's mighty crowded up there with 600W of panels. You would be covering fans A/C and skylights if you add another 4 panels. While higher wattage panels sound like an answer, they are bigger so you actually have more trouble fitting things in.

Two BB's will fit under the center of the couch / recliner just fine / no sweat. Anything more than that under the couch .... unlikely. The space under each recliner is not as "empty" as you might think. The mechanism traverses more of the space than you might think. I am running 2 batteries indoors and 2 outdoors (in the stock battery box). Getting to a total of 6 probably would mean putting 2 more under the rear dinette seat or someplace like that.

Bob

[Ephraim]

Originally Posted by uncle_bob

Hi
Getting to a total of 6 probably would mean putting 2 more under the rear dinette seat or someplace like that.

Bob

That may be an option. Right now, the drawer under the read dinette seat is unusable space. The wife wanted to protect the woven flooring so she got natural fiber rugs to cover pretty much everything. Then she got worried that natural fiber next to the stove wouldn't be a good thing so she covered that with a padded rubber mat (cause she liked the feel of standing on that). Yep, you read that right. We have a rug to protect the rug to protect the rug that protects the floor. What is a guy going to do...

Anyway, that means you can't open that drawer without moving rugs. I might just confiscate that space for batteries.

[Al and Missy]

Originally Posted by Hein

If neutral is bonded in two places (host and trailer) then current will flow along the ground wire between them. The GFI on the host system is detecting the leakage and tripping. If the host is not GFI then you could have a hot skin condition. Definitely a safety issue to be avoided.

I am not electrician but that is my understanding. Please correct me if I am wrong.

All the best,
Hein

You asked

Current on the ground wire has nothing to do with GFCI actuation. A GFCI senses the local current on the hot (black) wire and compares it to the neutral (white). If it exceeds a certain value (I don't remember the number so I'm not going to guess) it trips. That is how they are specified and tested for acceptance.

Al