Inverter Issues popping GFCI-Found Possible Cause

CDN

B and B
Been on two trips so far with the Landmark. Both times the GFCI has blown on the inverter when travelling. Yesterday I went to my storage lot, stationary Landmark not moving, GFCI blown on the Inverter. Running on Solar right now.

Called Heartland service spoke with a service advisor on the issue. He said you are going to have to find and troubleshoot the issue, take it to a Heartland Service Centre to have this done, I said my dealer is booking into August now. He stated any Heartland service centre. I said that really is not very helpful as the other two will not service non purchased Vehicles. Only one Landmark dealer in Ontario. I was respectful in tone, he hung up on me. Unacceptable!

I took it upon myself to do some testing tonight. Looked at transfer switch, all wiring is solid inside, checked for Neutral-Ground-Hot shorts. Checked the flat pack SJT to Romex connectors all good there as well.

Go to behind the drawer in the kitchen where the fridge is plugged into. The plug is bent sharp at right angle and creased really badly. They (someone at heartland) mounted the outlet on the wall one time wrong, mounted it a second time wrong again. The one screw was pulled out if the wall due to the drawer hitting the plug. I removed this from the wall and set on the floor behind the drawer, straightened out the lead cord for the fridge.

I need some help to monitor things while i manipulate the plug to see if this is the casue. My money is on this being the issue right now.

I will update this with pictures and findings. We travel tomorrow to the Ontario Rally, if it works all the way I believe I have found the issue.

At this point this Broadcast Engineer who has manufactured equipment and obtained CSA/ Ontario Hydro Special certification really wonders how Heartland electrical system can even comply with basic requirements with workmanship like this. This is not the first electrical problem I have encountered with this trailer, several more serious ones.

Brian
 
Last edited:

CDN

B and B
Update!

The Inverter ran while travelling to the Rally in McGregor. The little bit of charge and fridge full of food sustained the available battery reserve.

The actual ground on the fridge plug is broken, so this definitely rules out the GFCI tripping due to an issue with the Fridge. There is no ground return path for the GFCI to even trip on.

I emailed my dealer today with my findings.

I also received a call back from Heartland service today, they read or where made aware of the above post. Thank you for this if someone emailed them with my concerns.

I had asked about GFCI tripping when battery power was exhausted below usable level. The Heartland person was unaware or unused if this would happen.

I received a call back from my Dealer Service manager today as well. In discussions with the Service Manager and Lead tech we discussed my issue. He owns a Landmark himself and had the exact same issue. After changing to 6 volt batteries the problem went away, no more tripping or issues. I have an appointment in two weeks after our next trip and we are doing a deal returning the 12 volt batteries and putting in a pair of 6 Volt trojan batteries.

So as I did suspect from the start something collapes in the Inverter output stage causes a ground imbalance tripping the GFCI. I would love to prove it with a Scope and monitor the output waveform, I bet the modified sine wave causes some type of spike taking out the GFCI prior to actually shutting off due to low battery level.

More after I get new batteries in a couple weeks.

Brian
 

jbeletti

Well-known member
Brian - happy to hear you got a call back from Heartland. Bummer that your matter is not resolved just yet. This type of inverter issue is a bugger to resolve. I had the same issue in my last Landmark. I tried a good many troubleshooting steps and various setups.

I replaced the Inverter once to no avail. I then replaced the GFCI outlet with a standard outlet. Heartland cannot advise you to do this. I'm just intimating my personal experience.
 

wdk450

Well-known member
Update!



The actual ground on the fridge plug is broken, so this definitely rules out the GFCI tripping due to an issue with the Fridge. There is no ground return path for the GFCI to even trip on.


Brian

Brian:
The GFCI trips on an IMBALANCE OF CURRENT FLOW comparing the hot wire and neutral wire of the circuit feeds. The ground being connected or disconnected on the refrigerator should have no bearing on whether the GFCI works correctly or not. The ground wire being connected properly to an earth ground connects the exposed metal surfaces on the refrigerator to ground, and comes from an earlier system to protect people from shocks. If you look at the illustration on the right of the GFCI Wikipedia article, you will see that the ground is not even drawn in there. https://en.wikipedia.org/wiki/Residual-current_device

On Edit: Brian, I also agree with you that the fact that the grounding on the refrigerator metal shell was not connected makes refrigerator electrical leakage an unlikely source of your GFCI trips, since the normal theory of GFCI says that the electrical leakage that trips the GFCI goes to the ground wiring circuit. Without the plug grounding pin in place, this leakage voltage would just be on the refrigerator metal case waiting for a human to make a ground path, and producing an electrical shock. At that point (assuming the leakage current is over the GFCI minimum) the GFCI should instantaneously trip, removing the voltage to the refrigerator, and protecting the humans involved from large electric shock.

Doing some more Websearching on the subject of inverter power and GFCI's I came across this interesting document from Xantrex, a major inverter manufacturer: http://maze.airstreamlife.com/wp-content/uploads/2016/12/Xantrex-inverter-GFCI-Tech_Note_018.pdf

I decided that the last paragraph of the document provided a gleam of explanation of this intermittent and perplexing problem and was worth posting on the forum along with the weblink.

"Nuisance tripping would be defined as the GFCI holding OK on shorepower but tripping when inverter power is present. This can sometimes be caused by marginal leakage between neutral and ground within the GFCI protected circuit. This marginal leakage is not enough to cause a shock hazard but may be enough to trip a GFCIwhen inverter power is present. This marginal leakage is often caused by surge suppression circuitry in some types of electronic equipment that may be connected to the circuit. This surge suppression circuitry sometimes includes capacitors between hot and ground and between neutral and ground. On sine wave shorepower, these capacitors will not couple enough energy to ground to trip a GFCI. But with inverter power, the capacitors couple more energy due to the harmonics contained in the waveform, and this can be enough to trip a GFCI."

This mention of surge suppressor circuitry rang some "I've seen that" bells in my head. Actually it was in the mid 1980's when IBM PC's were being equipped with dedicated input circuitry and software, and being sold to medical facilities as medical diagnostic devices for the first time. ALL of the IBM PC's were failing the much tougher medical electrical leakage limits. I traced the problem to the incoming power line filtering on the computer that utilized filter capacitors from hot and neutral to ground. These capacitors passed enough leakage current to ground to cause the PC's to fail the incoming device electrical leakage tests. Clipping out the capacitors and seeing the leakage current readings drop to acceptable medical device levels proved that this was the source of the excess leakage.

This AC power line filtering is REQUIRED by the FCC (to minimize radiated interference signals) on all line powered devices that have digital circuits - That is MOST EVERYTHING nowdays. Does your refrigerator have a digital readout or control? One fix that should work is to have your inverter output drive a 120 volt 1:1 ISOLATION transformer to which your refrigerator is plugged into. This is akin to powering your refrigerator with an ungrounded battery system. You could theoretically grab either output wire of an isolation transformer and not get a shock since the voltage is "floating" and does not seek or know what ground IS. This is used in defibrillator paddles - the current only wants to go to the return paddle, not to ground.
 
Last edited:

CDN

B and B
Re: Inverter Issues popping GFCI-Found Possible Cause- Part 1 Resolved

Update

We ran on the Group 24 12 Volt batteries for a trip. The Invertor was extremely touchy with low voltage drops, like when slides are put in or jacks raised. I turned on the invertor after jacks where retracted and slides in. This allowed the invertor to run while driving.

Today I dropped by my dealer for a the usual post camping stop.

I went in for awning cylinder replacement on the awning arm. Ended up getting a great deal on a pair of Trojan T105 6 volt batteries and a pair of battery boxes for for free. I need to fashion the vent myself and was able to return the dealer supplied group 24 for a $200 credit.

The service manager lead tech did the same thing on his Landmark and it solved his inverter problem.


Once I get the venting work done I will hook up solar and report back.
 

CDN

B and B
Further Update July 8th

6 volt batteries work great! The run slides and jacks great, no pump groaning or slowing at all. I confirmed full charge with specific gravity measurement of each cell.

I have my dealer getting a new inverter as this one continues to blow the GFCI.
If it continues after this field engineering will dictate a modification to the inverter.


Sent from my iPhone using Tapatalk
 

For20hunter

Pacific Region Directors-Retired
I am really curious to see what cures this, as I am having the same problem. I have replaced my inverter 3 times at Heartland's request and it still continues to pop our GFI on our inverter. I have checked the wiring for the fridge plug and it is wired correctly and has no kinks or bends. I have checked the converter and its wired correctly and all connections are tight. I am not sure what else to check.

Rod
 

CDN

B and B
My wiring checks fine and shows no leakage to cause a GFCI to trip. I placed portable GFCI on my fridge running on shore power and it never tripped.

After I get my new Inverter if it doesn't work and I am going to check out the theory I have what might be happening.

The inrush current needs of the Lippert levelling system might just cause a drop on the 12 volt system enough that the Pure Sine Wave inverter might be collapsing creating a non sine wave output popping the GFCI due to the way it works. I am sorry this all technical but there needs to be a valid reason why it happens. Time to pul out the scope and look at this.
 

For20hunter

Pacific Region Directors-Retired
Mine trips while driving and nothing is being operated other than the fridge, so the level up is not the cause for mine.

Rod


Sent from my iPhone using Tapatalk Pro
 

LBR

Well-known member
Our 1000 W inverter tripped occasionally for about a year...it was always when the 2-12V batteries were low on static voltage. Since installing the 400AH lithiums, the inverter GFCI has not tripped once.

Prior to installing these batteries, I credited the problem being the refrigerator's compressor starting windings being the culprit when batteries couldn't supply the required amperage at the lower voltages. I still lay blame to that being the problem...the great battery bank rectified my issue anyway.
 

jbeletti

Well-known member
Mine trips while driving and nothing is being operated other than the fridge, so the level up is not the cause for mine.

Rod


Sent from my iPhone using Tapatalk Pro

Mine was the same - tripped while driving. Crazy. Post #3 for my solution.
 

Terry H

Past Texas North Chapter Leader/Moderator
Staff member
Mine trips while driving and nothing is being operated other than the fridge, so the level up is not the cause for mine.

Rod


Sent from my iPhone using Tapatalk Pro

When you are driving with the fridge on, is the ice maker on? If it is it may be possible that when the ice maker is preparing to dump a batch of ice it trips GFi. There is a small heater in the ice tray that makes the ice easier to eject from the tray. If the ice tray heater is on when the compressor starts it may cause the GFI to trip. I had the GFI trip a few times when i traveled with the ice maker on. Since I now travel with the ice maker off, I have not had any problems with the inverter or the GFI tripping.

How a Refrigerator Ice Maker Works
 
Last edited:

For20hunter

Pacific Region Directors-Retired
Terry, I will try turning it off the next time we travel and see. Thanks

Rod


Sent from my iPhone using Tapatalk Pro
 

CDN

B and B
When you are driving with the fridge on, is the ice maker on? If it is it may be possible that when the ice maker is preparing to dump a batch of ice it trips GFi. There is a small heater in the ice tray that makes the ice easier to eject from the tray. If the ice tray heater is on when the compressor starts it may cause the GFI to trip. I had the GFI trip a few times when i traveled with the ice maker on. Since I now travel with the ice maker off, I have not had any problems with the inverter or the GFI tripping.

How a Refrigerator Ice Maker Works


Very good point Terry. My icemaker has a plastic tray that moves upside down to dump the ice. I am not sure if they use a heater like a traditional plate type ice maker. Going to check this out tonight.

https://files.bbystatic.com/5/LvAPcT4wcvxc5aIhpL7A==/NS-RFD21SS7_18-0391_WEB_V10_EN_Final_lr.pdf


If this is the case that would tell me the Inverter is undersized for the load. More investigation and of course if it fails after getting my replacement I will be doing the Jim B. mod to inverter.


Brian
 

jbeletti

Well-known member
When you are driving with the fridge on, is the ice maker on? If it is it may be possible that when the ice maker is preparing to dump a batch of ice it trips GFi. There is a small heater in the ice tray that makes the ice easier to eject from the tray. If the ice tray heater is on when the compressor starts it may cause the GFI to trip. I had the GFI trip a few times when i traveled with the ice maker on. Since I now travel with the ice maker off, I have not had any problems with the inverter or the GFI tripping.

How a Refrigerator Ice Maker Works

Great info Terry. Looking forward to the test results of a few others. More data points should prove this one out. Another idea for those who have a logging amp meter is to record AC current (on the refer branch circuit out of the transfer switch during a travel day with the icemaker on and a mold full of water. Knowing what the "real" max current draw on the refer circuit is would be good to know.
 

wdk450

Well-known member
Just to throw another possible cause out there . . . The GFI relay can trip from strong mechanical shocks. At one time at my home I wired a GFI outlet into a metal outlet box wired to the end of an outdoor extension cord. I found that when this setup was dropped from even a low distance (2-3 feet?) the GFI would trip.
 

CDN

B and B
Just to throw another possible cause out there . . . The GFI relay can trip from strong mechanical shocks. At one time at my home I wired a GFI outlet into a metal outlet box wired to the end of an outdoor extension cord. I found that when this setup was dropped from even a low distance (2-3 feet?) the GFI would trip.

Hi Bill,

The Inverter is mounted vertical in the front bay, looking at the installation instructions they say either flat mounted to the top or bottom of the shelf. I received my replacement inverter today and am going to try a mechanical shock test with existing unit.


Some other things I am doing.

I am preparing to use what I have for testing the next trip. I have a kill a watt meter and go pro, going to test with ice maker on and see what happens, sadly I don't have a chart recorder any more.


I have a call into Magnum tech support to ask some questions. I will ask the mounting location as well.

The Insignia fridge says 2.8 amps draw, the Inverter is suppose to supply 8.3 amps with close to 16 amps peak.


Brian
 

For20hunter

Pacific Region Directors-Retired
Traveled 690 miles with the ice maker off and it made no difference. Every stop we made the inverter GFI was tripped.

Rod


Sent from my iPhone using Tapatalk Pro
 

CDN

B and B
Following dealer course of action replaced inverter this morning. Found on install error. Flat washer and lock washer user the lug rather than on top. Safety bonding earth connection also was loose.
0d9304521578a8d63306adb7eda12465.jpg


Installed replacement correctly.

af77ff4e08ae39f51f292ba42adb5171.jpg


Fridge draws 1.30 amps. This is a warm fridge at 72 degrees F. After running for an hour the peak current registered was 2.3 amps, nameplate is 2,8 maximum.

fdf0955065d7303fdaaa86459c2849ff.jpg


We will see if this works as suggested.

Sent from my phone
 
Last edited:
Top