Hi,
We're sitting at friends' place and they have a 15a outlet nearby. It is protected by a GFCI so when I try to plug in the bus (using 30/15/50 adapters) it blows the gfci. I seem to recall a discussion about this on the forum, but I can't seem to find it. Does anyone know how I can defeat the GFI temporarily so I can plug in? My power runs through an automatic conditioner that tests voltage, polarity, etc. before allowing the power into the automatic switch which then goes into the main panel. I also have a Trace sw4024 in the mix.
Thanks!
Most likely you have the neutral and ground tied together somewhere on your bus. That's what will trip the GFCI.
The only times that neutral and ground should be tied together on your bus is when it is generating its own electricity and you aren't tied to shore power. In other words, only when you are running on inverter or generator.
So your generator can have its neutral and ground tied together all of the time as long as your transfer switch switches neutral as well as the hot(s), which it should.
The inverter should only tie neutral and ground together when it is running on battery (inverting). Some inverters have a relay inside to tie them together as needed, some don't and are tied together all of the time. I don't recall if that Trace does or not.
As far as bypassing the GFCI, you would need to require the outlet and your friend's house. But that would be defeating an important safety feature.
Hope that helps.
-Kitt
it does not take very many amps to trip...how many things are drawing current in your coach...
i would not defeat the gfci...it's doing it's job.
believe it or not i carry one of these....and enough 4wire SO Cable to use it....and an assortment of 50 amp breakers....
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fwww.rvparksupplies.com%2Fmm5%2Fgraphics%2F00000001%2FRVPOWEROUTLETPANEL.jpg&hash=092d25ad4638eb28b2ca4d6cd6c0a4875b6036ea)
The only way to un-GFCI a GFCI outlet is to take it out and replace it with a non-GFCI outlet. If you want to do that on a temporary basis you could, but you would lose the GFCI protection on not only that outlet but also on any down-stream outlets. Is that good or bad? 90% of outlets in my house are non-GFCI including the outside outlets, since they were installed before the advent of GFCI. GFCI detects the current difference between live and neutral, it does not need a ground to work. If your bus is tripping it, I would start by opening the main breaker in the bus and see if it still trips, then close it and open all of the other breakers, etc. If you have neutral bonded to ground somewhere in the bus, you'll need to find it. With a neutral-ground bond, some of the return current will pass through the ground, and as little as 5 milliamps can cause a GFCI to trip. That's not a lot of leakage to ground.
It could be tripping the GFI before the automatic transfer in the inverter is switching if you got two of those ground adapters like the old days when outlets were not grounded and tried connecting the ground after it gets power. just be careful because you might really have a problem
Quote from: wagwar on August 23, 2014, 10:32:54 AM
Hi,
We're sitting at friends' place and they have a 15a outlet nearby. It is protected by a GFCI so when I try to plug in the bus (using 30/15/50 adapters) it blows the gfci. I seem to recall a discussion about this on the forum, but I can't seem to find it. Does anyone know how I can defeat the GFI temporarily so I can plug in? My power runs through an automatic conditioner that tests voltage, polarity, etc. before allowing the power into the automatic switch which then goes into the main panel. I also have a Trace sw4024 in the mix.
Thanks!
Dave - are you using a cheater adapter that ties (2) 20 amp or (1) 30amp and (1) 20 amp to a 50amp plug? Those tie the ground and neutral together in the plug itself to work. I've got one I use all the time and it will not work on any gfci outlet. There is no way to beat it except to change out the outlet or find another non-gfci outlet. Also - if there is a gfci outlet anywhere in the circuit it will trip the breaker even if you have it plugged into a non-gfci plug.
There are 30 amp to 50amp adapters that do not tie both hot legs together that will work fine (unless as previously mentioned the neutral and ground are bonded somewhere in the bus but they should not be bonded in the bus...only at the generator when that is running and possibly the inverter when on battery only power)but you will only get power to one leg of the breaker box. We have our electrical so the charger/inverter, hot water heater and front AC are all on one leg of the electrical and everything else on the other so that we can use just one 20amp connection and breaker on/off as needed to get by.
-Sean
As others have pointed out, you may have a legitimate ground fault that you should find and fix. Common culprits are just plain bad wiring or possibly an electric water heater where the element is starting to deteriorate, allowing current to leak to ground through the water. With your inverter turned off use a VOM to check for continuity between the green and white conductors on your shore cord. If they are isolated then the inverter is likely the problem. In my case my old Heart inverters won't release the bond fast enough to allow us to use a GFCI outlet. We've had some bad days as a result and we have developed workarounds for those situations. I'm not going to tell you in an open forum how to get around NEC, Google is your friend.
I have a Trace SW2512 (vintage 1999 year model). It acts as a pass through in addition to a battery charger when tied to the grid or running on the genny. I suspect yours does the same. The neutral and ground are tied together at the inverter case with a green wire and a nut with a lock washer which is easily accessible on mine. I had your problem and temporarily disconnected the case ground at the inverter to use the GFI plug at the pole. Doing this creates only one bond at the grid pole.
We've had numerous discussion here about grounds and neutrals. No one knows why the ground on the inverter is not released when external power is applied. It should be to avoid double bonding. It should have been designed to bond to the neutral only when stand alone inverting. If on the grid the bond should be at the pole. If on genny the bond should be at the genny.
Sean is our electric guru. He should jump in with some better advice.
Good luck
David
Quote from: David Anderson on August 23, 2014, 05:11:54 PMSean is our electric guru. He should jump in with some better advice.
Good luck
David
Just to Clarify....I am not the Sean you are looking for.....
-Sean (not the original)
Quote from: David Anderson on August 23, 2014, 05:11:54 PM
I have a Trace SW2512 (vintage 1999 year model). It acts as a pass through in addition to a battery charger when tied to the grid or running on the genny. I suspect yours does the same. The neutral and ground are tied together at the inverter case with a green wire and a nut with a lock washer which is easily accessible on mine. I had your problem and temporarily disconnected the case ground at the inverter to use the GFI plug at the pole. Doing this creates only one bond at the grid pole.
We've had numerous discussion here about grounds and neutrals. No one knows why the ground on the inverter is not released when external power is applied. It should be to avoid double bonding. It should have been designed to bond to the neutral only when stand alone inverting. If on the grid the bond should be at the pole. If on genny the bond should be at the genny.
Sean is our electric guru. He should jump in with some better advice.
Good luck
David
I also had this problem. I built Sean's transfer switch and have A SW4024. I had to be sure the hot and neutral blades made contact first by tilting the plug. Once the switch had shore power it would then switch the neutral and then it wouldn't trip the GCFI. It only takes a split second then ground blade can engage. I don't really know how to explain this any better. You could look for an adaptor that has a slightly shorter ground prong. (Hint) Then the hot and neutral prongs would engage first before the ground prong.
John
I also have a SW4024 (RV) and have the same issue. I disconnected the green wire on the inverter and it still tripped the GFIC even with the inverter input dialed down to 12A. Don't think there is a way around it. Heard you could tilt the plug when connecting but have not personally tried it. I had to replace a GFIC plug in my shop with a regular one to solve the problem. On the road it's a different story.
Quote from: Jriddle on August 23, 2014, 06:55:27 PMI also had this problem. I built Sean's transfer switch and have A SW4024. I had to be sure the hot and neutral blades made contact first by tilting the plug. Once the switch had shore power it would then switch the neutral and then it wouldn't trip the GCFI. It only takes a split second then ground blade can engage. I don't really know how to explain this any better. You could look for an adaptor that has a slightly shorter ground prong. (Hint) Then the hot and neutral prongs would engage first before the ground prong. John
Yes, this is a question that's bothered me. The standard safety feature is that the ground should be connected in a standard 15-amp plug before the hot and neutral prongs make connection. That's a good thing. But with my bus, it gets me into the loop of the ground section of the transfer switch tripping the GCFI socket. Most transfer switches are made to properly bond/unbond ground as they switch from the different power inputs and in some of the conditions, the transfer switch makes its internal ground connection before it switches the hot and neutral connections. This is a good safety feature. Unfortunately, it "fools" at GCFI into thinking that there is a ground fault.
In a previous post, someone gave details of a "delay box" for just such issues. You take an ordinary insulated electrical connector box and install a section of Romex (or your preferred 120V cable) with the hot and neutral straight-through. For the ground cable, put in a normally-closed push switch; then install a male and female plug/socket on each end of the cable. If your system is working safely, you should be able to hold down the push switch, plug into the GCFI and when the transfer switch has completed its switch over to shore-power, release the push switch. Someone also said that you can get the same result by cutting down the ground pin on the extension cord plug and plugging in the cord slowly into the GCFI. (On my bus, you can hear the transfer switch make a dull "clunck" sound as it switches and sometimes this is 1-2 seconds after I connect the shore cord.)
What worries me is that it seems very hard to tell the difference between "Safe - Normal but has to be overridden for a second or two" and "Unsafe - not Normal and if you override it, you're creating an unsafe condition".
Everything about the operation of my bus leads me to think that the grounds and neutrals are correctly bonded and unbonded by the automatic switching of the transfer switch and inverter. But I have this issue with GCFI outlets. Where I often park, there is an outlet box that has both an ordinary three-connector outlet and a GCFI outlet. If I plug into the ordinary outlet, my system works fine and all the testers indicate that I have no problem. I have not tried any "dodge" on a GCFI -- maybe the override box or the shortened ground pin would be fine -- and maybe it would all work OK. I don't know but I am just not comfortable with a situation that doesn't make common and dangerous faults plain.
Still no joy.
Here's what I've tried:
1. Turn all the breakers in the main panel off.
2. Turn the AC input breaker to the inverter off.
3. Disconnect the 'green' ground inside the inverter.
4. Turn the inverter off.
5. plug into the gfi and turn the main breaker (pedestal to bus) on.
At this point, the power conditioner cuts in allowing AC voltage into the bus. The ATS cuts in allowing power to the panels and (I assume) bonds the ground-neutral. All is well. The inverter indicates an AC input voltage OK.
6. Reconnect the green ground inside the inverter. The gfi blows.
I have tried the above in different orders, but same result.
It seems to me that if I had a ground fault in the bus or a problem w/ the ground-neutral bonding, turning all the breakers in the main panel would eliminate that as a possible cause. What am I missing?
Is it acceptable to leave the green wire disconnected inside the inverter - just long enough to get my batteries charged back up?
Thanks,
Jim
I think the inverter is bonding neutral and ground. Since you are plugged into a GFCI outlet you will be protected if anything in the bus develops a path to ground, so I would go ahead and charge your batteries with ground disconnected. If anything can/will give you a shock for any reason, the gfci will trip because there will be an imbalance in the current in live and neutral (whatever current is leaking out and shocking you, etc). This is a permitted application to use GFCI to protect ungrounded outlets, and what you're doing amounts to the same thing.
Brian
I tried leaving the green ground to the inverter disconnected. It worked ok for a fe minutes, the the gfi kicked out again. I set the charge amps on the inverter to 4 and it still kicks out after about 5 minutes. Any other suggestions?
Based on what I've read I'd say you have at least two ground fault paths. The inverter is clearly one path since it trips the GFI immediately if you connect the bond. Do you have an electric water heater? If so then trip its breaker to off and see if the problem persists.
Dave - If you are plugged in does the inverter need to be inverting?
On my inverter if we are plugged in the inverter switches to charging only and passes through the 120v straight to the outlet.
If your inverter is inverting while plugged into 120v then the ground and neutral will be tied together and the GFCI will blow.
Interesting if its still blowing with the ground disconnected. Wondering if there is an issue inside the inverter itself?
-Sean
Quote from: Seangie on August 25, 2014, 05:14:41 PM
Dave - If you are plugged in does the inverter need to be inverting?
On my inverter if we are plugged in the inverter switches to charging only and passes through the 120v straight to the outlet.
If your inverter is inverting while plugged into 120v then the ground and neutral will be tied together and the GFCI will blow.
Interesting if its still blowing with the ground disconnected. Wondering if there is an issue inside the inverter itself?
-Sean
Guess this was a question for me.
On my SW2512 it will invert if the shore cord size selected on the menu is less than the amps being drawn by an appliance using electricity. ie, if I set cord size to 8 amps and wifey turns on a hair drier, (12 amps) the pass through feature will give me 8 amps from the power pole and 4 amps inverted off the batteries.
It does not blow the GFI if I disconnect the case bond wire from the inverter cabinet. I've only done this one time in 14 years since I have only hooked up to a 15 amp GFI plug once. All other times it was either a 30 amp or 50 amp plug.
Interesting comment about the water heater, though. Wonder if there is something there??
David
Quote from: David Anderson on August 25, 2014, 07:07:19 PM... On my SW2512 it will invert if the shore cord size selected on the menu is less than the amps being drawn by an appliance using electricity. ie, if I set cord size to 8 amps and wifey turns on a hair drier, (12 amps) the pass through feature will give me 8 amps from the power pole and 4 amps inverted off the batteries. ...
You're lucky there. On my Outback, there are many features but if the max input is set at 8 amps and wifey plugs in a hair dryer, it shuts down the input and pulls *all* the power from the inverter/batteries. One thing I don't like ...
Since someone mentioned me by name, I thought I'd jump in for a minute...
First and foremost, you need to make sure there is no inadvertent ground fault in your system. Lots of ways to do that, which have been covered here before.
That said, the Trace SW series will trip GFCI outlets all by itself, even with no ground fault. This is due to a filter capacitor. I wrote about the solution extensively here:
http://www.busconversions.com/bbs/index.php?topic=3285.msg29365#msg29365 (http://www.busconversions.com/bbs/index.php?topic=3285.msg29365#msg29365)
Once you've ensured there is no real fault, and removed the green strap inside the case (which is NOT a ground/neutral bond and NOT a case ground) that I discussed in that post, you will STILL have a problem from the ground/neutral bonding relay that should have been installed along with the Trace. I discussed that issue here:
http://www.busconversions.com/bbs/index.php?topic=16322.msg175595#msg175595 (http://www.busconversions.com/bbs/index.php?topic=16322.msg175595#msg175595)
Lastly, even if all the above have been covered, your front-end power management and monitoring may, by itself, trip the GFI. All I can say here is you can either live with it, or bypass the monitor. Without seeing a schematic I can't say for sure if this is part of your problem.
Hope that helps.
-Sean
First, thanks to all of you for your help.
Can you explain why I can get it to work for 4-5 minutes before the gfi blows? I have dialed the trace down to 4a charging current and it still blows.
I'm beginning to believe that I have a ground - neutral bonding issue or a simple ground fault. However, I don't know how to go about running those issues down. I found the following thread wherein Sean describes a series of tests for these issues. To the best of my ability, I have done these tests and all checks out OK. Still, after about 5 - 10 minutes of charging, the GFI blows.
http://www.busconversions.com/bbs/index.php?topic=12442.msg130556#msg130556 (http://www.busconversions.com/bbs/index.php?topic=12442.msg130556#msg130556)
(there is one part of Seans instructions that I did not understand "Make sure any generator or inverters aboard are also disconnected." - as I don't know specifically what that means)
I have an ESCO 350 ATS that handles the switching of generator/shore/inverter, but a conversation with ESCO TS reveals that switch does NOT do any kind of neutral/ground bonding or "lifting". I know that my generator ground and neutral are bonded to the chassis at the generator, but I am not able to discern how the neutral-ground bond is being lifted (if it in fact is). I have never had any problems with my electrical system either on gen/shore or inverter.
I welcome any suggestions as to how to proceed.
If you had a ground it would trip the GFI instantly that is the purpose taking minutes sounds like a overload but I not that up on inverters and grounds either
Quote from: wagwar on August 26, 2014, 11:10:11 AM
I have an ESCO 350 ATS that handles the switching of generator/shore/inverter, but a conversation with ESCO TS reveals that switch does NOT do any kind of neutral/ground bonding or "lifting". I know that my generator ground and neutral are bonded to the chassis at the generator, but I am not able to discern how the neutral-ground bond is being lifted (if it in fact is). I have never had any problems with my electrical system either on gen/shore or inverter.
I welcome any suggestions as to how to proceed.
The Esco ATS has relays that switch the two live leads and the one neutral lead (it's a 50 amp 120/240 volt three source ATS) so that whatever power source is providing power is switched through to the load. Since it switches all three leads, any ground-neutral bonding that is present at the power source in use is also switched through. That means the ground-neutral bond at the generator is "lifted" - actually just disconnected from the bus power system - when the ATS is not using the generator for power.
Did you remove the jumper that connects that filter cap that Sean referred you to? Is the GCFI now tripping after 3 - 5 minutes with the ground connected or disconnected to the bus? I can't think of anything that would slowly and consistently develop a current leak in the 5 - 10 milliamp range over a period of minutes. I just had a thought - how long is your power cord to the bus, what gauge is it, and is it coiled at all or laid out straight? A coiled cord will inductively couple from live or neutral to ground. Even a longish uncoiled cord can inductively couple.
Edit: I want to go on record that I thought of the long coiled cord thing BEFORE I googled it and found that it's a known cause of nuisance trips. I also want to know if you've checked the obvious stuff like other outlets with stuff on them downstream of that outlet, and if it's an outside outlet possible corrosion or moisture?
Brian
Our GFI is in the breaker box inside the house not on the plug ours would always pop if she had something plugged in on one of the GFI outlets which she always did I finally tossed the 15 amp and installed a 20 amp GFI breaker in the box very seldom does it ever pop now ::) should have went with 30 amp
What gauge is the wire fed by that breaker?
Brian
Clifford, Thanks! Brian, Good to know maybe I don't have a problem with the neutral-ground bond. However, during my testing - read more below, if I throw one of my main panel breakers ON, the GFI immediately blows. If I leave all of them Off, it works for 5 - 10 minutes and then blows.
I have disconnected the green ground wire in the Trace and left it disconnected. The shore cord is a 50' 30amp 10 ga. It is not curled up - I always stretch it out and then bring it up to the bus. However, I have a 15/30 adapter at one end and a 30/50 adapter at the other. This 15 a circuit is in an outbuilding that is quite a long distance from the house panel and it has a household refrigerator on it that I cannot disconnect. In consideration of that possibility, I set my inverter to Charge only (no invert) and the charge amps to 5A. During my testing, I had all breakers in the bus Off so that only the inverter/charger was pulling a load. I have a power conditioner that indicates 117 volts AC, 5A AC and 60 hz after throwing the breaker in the bus. Those values hold steady until the gfi blows.
What gauge is the wire fed by that breaker?
Hard to say, but most likely standard household 12 - 14 ga. It is enclosed in flexible metal conduit. The unknown is the gauge of the cable to the outbuilding.
I don't know if this is possible bus could a 12 volt DC from the battery negative be bleeding off and tripping the gfi. Just thinking out loud.
Quote from: Rick 74 MC-8 on August 26, 2014, 06:46:30 PM
I don't know if this is possible bus could a 12 volt DC from the battery negative be bleeding off and tripping the gfi. Just thinking out loud.
Rick - This would be a fault only if the neutral is tied to the frame or another ground at some point....which would be a good thing to check.
Dave (Wagwar) - Make sure that in your service panel (In the coach) your neutral bus bar is not tied to the ground bus bar at any point. Its not uncommon in a house to see the neutral and ground tied together on the same bus but you dont want this on your Coach. Your coach main panel needs to be treated like a sub-panel in which the ground and neutral are not tied together. I think we all assumed this but I dont think it was specifically mentioned.
-Sean
If the GFCI in question is working properly, then any ground-neutral fault in the coach would trip it instantly. The fact that it is not tripping instantly means that either it is inoperative, or else you don't really have such a fault in your coach. Step one here would be to test the GFCI. The self-test button is unreliable; instead, purchase a GFCI tester -- this is one of those little three-light testers that also tell you if the outlet is properly wired, except that it also has a little button you press to test the GFCI. Available at Home Depot and elsewhere, they are maybe $15. Handy to have, because you can never tell when a plain-looking outlet might be wired downstream of a GFCI, and this lets you know right away.
Now, having said all of that, my experience is that GFCI outlets that nuisance-trip after a period of time (as opposed to when you first plug in) are also defective. One common issue is moisture in the J-box, which can become just conductive enough to cause a trickle current between either the hot or the neutral and the ground. When you think about it, moisture is exactly one of the reasons GFCI outlets are so important in the first place.
If your coach is tripping this one outlet consistently after a period of time, I would not implicate the coach itself unless is also does that consistently to other GFCI outlets. If you can't find another outlet nearby to test, then drop the $20 and replace your host's receptacle for him, and see if the problem goes away. We carried a spare GFCI with us for exactly this reason. (We also carried spare 50- and 30-amp breakers for defective campground pedestals, along with spare receptacles. When you get the last good spot at that remote state park, it's easier to just fix the dang pedestal than to move or try to get rangers or volunteer hosts to do anything about it.)
HTH,
-Sean
It does not trip instantly, until I flip one of my breakers in the bus on (eg entry door receptacle). Recall that I have all of my breakers off. With all breakers off the gfi will pop after a few minutes of charging- even at a low 5a level. If I flip a breaker on, that will cause it to pop immediately. So, still not able to definitively rule out neutral ground bond or ground fault problem.
Btw, I can confirm that neutral and ground are not bonded in main panel, so if it is a neutral ground bond problem, it is not happening at my main panel.
Pro already been mentioned--Grounds bonded within some appliance. Been there on that one.
Dave (wagwar) -
How did you make out? Any progress?
-Sean
Not really. I swapped out the gfi for standard rec. temporarily. I need to thoroughly test the neutral ground bond for proper operation, but I just don't know how to go about it.
The tests that Sean outlined in the previous thread that I linked to in a previous response seem to check out ok. So I'm not sure where to go from here. I think i may still have a problem.
Just a question. Would using one of those little 3 prong to 2 prong adaptors have worked since it cuts out the ground?
Quote from: Lin on August 31, 2014, 10:06:25 PM
Just a question. Would using one of those little 3 prong to 2 prong adaptors have worked since it cuts out the ground?
Sometimes. Yes. But. ........
If the ground fault is a connection between the ground and neutral (green/white) on the coach then the 3 to 2 adapter will let you hook up. Whatever you have for a ground fault still exists - you've just masked its effect.
If the ground fault is an alternative path to ground - ie. not through the green wire - then the 3 to 2 adapter won't change anything.
I can think of situations where the 3:2 adapter might be an acceptable risk --
FOR ME --- but I can also remember homes that were wired with only 2 conductors. We don't do that anymore either.
Ultimately this comes in the category of "if you have to ask the question then you shouldn't try it at home".
Quote from: bobofthenorth on September 01, 2014, 11:16:26 AM
Sometimes. Yes. But. ........
If the ground fault is a connection between the ground and neutral (green/white) on the coach then the 3 to 2 adapter will let you hook up. Whatever you have for a ground fault still exists - you've just masked its effect.
If the ground fault is an alternative path to ground - ie. not through the green wire - then the 3 to 2 adapter won't change anything.
I can think of situations where the 3:2 adapter might be an acceptable risk -- FOR ME --- but I can also remember homes that were wired with only 2 conductors. We don't do that anymore either.
Ultimately this comes in the category of "if you have to ask the question then you shouldn't try it at home".
I remember living in a trailer house that was wired by a friend. Every time it rained we would get shocked when the door was opened from the outside. I guess we are lucky to be around to tell the story. You must ensure you don't become the ground for a ground fault. I guess at that time nothing would hurt me LOL. Young dump and ______?
John
REVISIT of the GFI Problem:
We are visiting our friends Howard and Ellen. Howard and I ran down the ground fault interrupt problem on this thread to an auxiliary Makita air compressor I had plugged into a GFI in the engine bay. After extensive testing, we discovered that unplugging the air compressor from the outlet, the GFI shore connection quit dropping. So apparently if I need to use a GFI outlet, I just need to unplug the air compressor. Perhaps the ground and neutral are bonded inside the compressor? I can't say. However at that point, we also had the Trace SW4024 inverter disconnected.
So then we reconnected the Trace SW4024 inverter. I had the inverter Off when we reconnected to the GFI. The power conditioner accepts the power. The auto transfer switch accepts the power and the main AC panel breakers are all ON. The GFI did not trip and I had power in the coach.
So I have no reason to believe that I have either a ground fault OR a problem with the neutral-ground bond inside the bus.
So then I turn on the inverter and a minute or so later, the GFI kicks out.
We checked the wiring into and out of the inverter, the automatic transfer switch and the breaker for inverter input and there is no obvious problem with the wiring. We have eliminated any ground faults or neutral-ground bonding issues in the main bus panel.
Still, I cannot connect to a GFI outlet with the inverter ON. If I leave the inverter Off, I have no problem. As soon as I turn the inverter ON - whether it is ON (inverting) or ON (Charge only) the GFI kicks out. I have also tried (as Sean Welsh suggested) to remove the spade connector inside the invertor for the ground relay connection. It makes no difference.
Any suggestions?
I just skipped through 3 pages of advice to give you my simple solution since I have the same setup--
I have a separate 40amp 3- stage 120v batery charger (plugged into the GFI) with 12v alligator clips I use in this situation. The house batteries stay charged for low usage of the inverter.
I also used to trip the GFI, this is how I got around that.
--Geoff
Outcome:
Sean and Robertglines called it right. After 2 days of testing and running down circuits from the house thru the ATS, Inverter and EMS, here's what it came down to:
1. The 120 vac Makita air compressor that was plugged into a GFI in the engine bay was causing a ground fault at the shore pedestal GFI. I suppose the ground and neutral are bonded within the appliance, simply unplugging it from the receptacle resolved that issue.
2. There was an additional ground fault occurring whenever the inverter was turned on. That turned out to be a weak GFI receptacle in the shore pedestal. A different GFI receptacle worked fine.
So, as it turns out there were no neutral-ground bond or ground faults within the bus wiring itself. I'm glad to know that.
Thanks to all of you who responded. This is a great resource.
Jim