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Old 01-16-2022, 04:42 PM   #1
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Model: Siesta
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THOR #3975
RV at home - electrical problem

I have a Thor Siesta Class C, about 5 years old. Wired for 30 amp service. Works fine plugged into a 30 amp breaker at RV camps, etc. Here's my problem:



The only power I have at home is 110 outlets. Lots of GFCI sockets - but no master circuit breaker at all. Don't ask why - it's an old house, upgraded before we bought it 6 or 7 years ago - but, as I said, no master, so upgrading to 30 amp will probably be a somewhat bigger job than normal - permits, etc. But I will do it gladly, if it will solve my problem. (And I should probebly do it anyway.) Right now I just want to charge the batteries a little when I am home. Storage is at an local parking lot with no power.



PROBLEM: If I am running on battery, and I plug the electric hookup into a 110V 15 amp circuit at home - it INSTANTLY pops the GFCI on my house (not the RV). Is this a house wiring problem - a short, I would call it - or is it just too little power - or is there some other RV electrical problem? As I said, plugging in to 30amp at RV camps works fine. I have a Progressive Industries surge protector - if I plug that into house 110 it says all OK - until I plug the RV into the surge protector - then POP - the GFCI in the house pops.


Any ideas about where my problem is? Is it just too much load for 110? Even tho almost nothing is on except the USE switch, maybe the water pump, idle, probably the fridge (I should probably turn that off for this) - and all the hidden parts of the electrical system that I know nothing about. Or is it some electrical problem with the RV? Or the house? Or ????


Help! And Thanks! And sorry this is so long...

Dan

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Old 01-16-2022, 04:55 PM   #2
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"it INSTANTLY pops the GFCI on my house"

Is the GFCI in the outlet? Or a breaker in the panel? Outlet GFCIs don't normally pop on overcurrent and there shouldn't be enough running in the MH to pop 15 amps anyway.

You have a common problem. It MAY be due to a construction fault in the MH where an errant screw has pierced the insulation on a neutral wire which wouldn't affect normal 30 amp connection/operation, but would definitely cause a ground fault when plugged into a GDCI circuit.

The other issue people find is that their MH was wired incorrectly with the neutral and ground busses bonded, which is incorrect and also causes a ground fault.

Some say the GFCI breaker in the MH causes the problem and you can open the breaker to that circuit in the MH as a work-around. That should not be the case, but if it works, it works.
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Old 01-16-2022, 05:06 PM   #3
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Try plugging it into a none GFI circuit. The gfi might also be defective. Where it trips too early.

Good luck
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Old 01-16-2022, 05:31 PM   #4
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Originally Posted by 16ACE27 View Post
Is the GFCI in the outlet? Or a breaker in the panel? Outlet GFCIs don't normally pop on overcurrent and there shouldn't be enough running in the MH to pop 15 amps anyway.

You have a common problem. It MAY be due to a construction fault in the MH where an errant screw has pierced the insulation on a neutral wire which wouldn't affect normal 30 amp connection/operation, but would definitely cause a ground fault when plugged into a GDCI circuit.

The other issue people find is that their MH was wired incorrectly with the neutral and ground busses bonded, which is incorrect and also causes a ground fault.

Some say the GFCI breaker in the MH causes the problem and you can open the breaker to that circuit in the MH as a work-around. That should not be the case, but if it works, it works.

The GFCI's are all in the outlets - the one I have easy access to, and a bunch of others. The panel looks like it was built when we discovered electricity.



I am aware of a GFCI socket in the bathroom of the RV, which we almost never use. Probably another behind the microwave/oven, which we never use - except to confirm we are getting electricity thru the surge protector, when we are at an RV campground.


I think I will get my electrician to put in 30 amp breaker in the panel, and a junction box right there as well, with a larger socket for the RV power cord. And a master breaker for the panel overall. And a permit from the city if necessary....


I have a appt for my RV dealer to do some mechanical service - I don't know what level of electrical expertise they have. If they understand things like: "It MAY be due to a construction fault in the MH where an errant screw has pierced the insulation on a neutral wire" or "MH was wired incorrectly with the neutral and ground busses bonded". If they do, I'll ask them to try to find and fix that...


Thanks!
Dan
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Old 01-16-2022, 05:35 PM   #5
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Originally Posted by smithgarnat@aol.com View Post
Try plugging it into a none GFI circuit. The gfi might also be defective. Where it trips too early.

I will see if I can find a circuit like that, and give it a try. They seem to have gotten a case of GFCI sockets when they remodeled, and used them all!


Dan
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Old 01-17-2022, 12:05 AM   #6
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I would suggest that the 15 AMP circuit in your home is not adequate to run your RV.

I would trip all CB in your AC panel, and then try plugging in.

Then turn on the RV master and only the DC converter. This will pwr the charger to your battery. On most RV, the battery will charge even though you have the DC master switch in the off position.

If you run the Refrig, this will overload house circuit.
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Old 01-17-2022, 12:56 AM   #7
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I would suggest that the 15 AMP circuit in your home is not adequate to run your RV.

People plug RVs into 15 amp circuits all the time. You can't run the microwave or AC and probably not the electric water heater element, but everything else should be fair game.

I would trip all CB in your AC panel, and then try plugging in.

Then turn on the RV master and only the DC converter. This will pwr the charger to your battery. On most RV, the battery will charge even though you have the DC master switch in the off position.

No, the "DC Master Switch" is a battery disconnect. The house batteries WILL NOT CHARGE with the battery disconnect open as many have discovered the hard way.

If you run the Refrig, this will overload house circuit.

Again, incorrect information. Both an absortion fridge as well as a residential fridge run at under 400 watts. That's less than 4 amps at 120 VAC.
So much misinformation in one post.
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Old 01-17-2022, 01:25 AM   #8
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Itís real easy to change out a 15amp breaker to a 30amp, find a outlet (preferably outside) and replace that breaker on that circuit, also what 16ace recommended, trip all your breakers in the MH plug into the 30amp circuit and turn them on one at a time, if one of your MH circuits trip the 30amp then you have isolated the problem circuit, but I believe the breaker replacement is going to solve your problem..

Pat.
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Old 01-17-2022, 01:37 AM   #9
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Quote:
Originally Posted by txc2936@yahoo.com View Post
I would suggest that the 15 AMP circuit in your home is not adequate to run your RV.

If you run the Refrig, this will overload house circuit.
Until I had a 50 amp dedicated circuit installed, I had two different 30 amp class C coaches and my present 50 amp coach plugged into a 15 amp outlet in my garage, using appropriate dogbone adapters of course. I kept the fridges, including the residential fridge in the present coach running along with the converter and occasionally the TV, and never overloaded the house circuit.
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Old 01-17-2022, 01:40 AM   #10
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Turn off the converter breaker in your MH. Plug in to your GFI outlet, then turn on your MH converter breaker. GFI circuits are very fussy and slight voltage leak during plug in of a standard plug can cause them to trip. This has been my practice for years and solved the problem for me.
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Old 01-17-2022, 04:44 AM   #11
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Originally Posted by lspotho View Post

.....cut.....

PROBLEM: If I am running on battery, and I plug the electric hookup into a 110V 15 amp circuit at home - it INSTANTLY pops the GFCI on my house (not the RV).

.....cut.....

Dan
Because it trips INSTANTLY at home but not at camp grounds, I think itís most likely that you have a grounded neutral in motorhome. Itís a common problem and fortunately one that is very easy to check.

If it is a grounded neutral, opening all breakers in your motorhome wonít keep your house GFIC from tripping. If house GFI trips anyway, you can confirm motorhome neutral is grounded with a multi-meter; or ask shop to check for you. Just takes a minute with OHM meter to confirm if that is indeed the problem. Could be many things that is causing your problem, but I would bet on it being grounded neutral.
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Old 01-17-2022, 10:05 AM   #12
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Originally Posted by Chance View Post
Because it trips INSTANTLY at home but not at camp grounds, I think it’s most likely that you have a grounded neutral in motorhome. It’s a common problem and fortunately one that is very easy to check.

If it is a grounded neutral, opening all breakers in your motorhome won’t keep your house GFIC from tripping. If house GFI trips anyway, you can confirm motorhome neutral is grounded with a multi-meter; or ask shop to check for you. Just takes a minute with OHM meter to confirm if that is indeed the problem. Could be many things that is causing your problem, but I would bet on it being grounded neutral.
Agree with Chance and 16ACE27. As mentioned the neutral (white wire) in your RV should not be bonded (connected) to ground (bare copper wire) in your RV. This is only supposed to happen in the pedestal at the campground. A simple way to think of how a GFIC circuit works is that all the current that goes out from the power source on the black wire should go back to the source on the white wire. In a correctly wired system there should not be any current carried by the bare copper wire. If your body comes into contact with the live wire (black wire) for what ever reason and you touch something like a stove that has its chassis connected to the bare copper wire current will flow thru your body back to the source via the bare copper wire. The GFIC circuit breaker senses this current flow in the bare wire by using a differential transformer between the black wire and the white wire. If the current at the center tap of the transformer exceeds about 20 ma the GFIC will trip thus keeping you from being electrocuted. If for some reason current greater than 20 ma is leaking to the bare wire in your RV then the GFIC will trip as soon as you plug into the 115 VAC outlet on your home. This can even be cause by water somewhere causing current to flow to the ground in the RV. It is most likely caused because someone added a device or replaced a device and wired it incorrectly. Folks often make this mistake because they know in there home in the breaker panel that the bare copper and white wire are connected together and think they are basically the same. If you add a second panel of breakers at your home for say a detached garage then the panel used there cannot have the bare and white wires connected together.

Get an ohmmeter and with the power cord from your RV not connected to anything and the generator and inverter off in the RV test the resistance between the round prong on the plug that you plug into your hose for resistance between the other two flat blades. They should not be connected.
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Old 01-17-2022, 10:26 AM   #13
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Since you only want to charge your batteries while parked at home, maybe just hook a battery tender trickle charger to them.

That would be an easy fix unless you wanted it plugged up to a 30 amp 110VAC to run items in the RV like the A/C or convection/microwave oven.

Before I had the RV outlet installed, I bought two battery tenders, ran leads from the coach battery bank to under the hood, and another off of the engine's battery.

With an extension cord, a multiplier plug, and two battery tenders, I can tuck them all under the hood out of the weather.
I still do this over winter because I do not want rodents nesting in the cord compartment with the window for the cord open.

Just a thought.

edit:
Oh yes, and while in storage this way, I switch the stow switch to the off position.
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Old 01-17-2022, 11:34 AM   #14
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Itís real easy to change out a 15amp breaker to a 30amp, find a outlet (preferably outside) and replace that breaker on that circuit, also what 16ace recommended, trip all your breakers in the MH plug into the 30amp circuit and turn them on one at a time, if one of your MH circuits trip the 30amp then you have isolated the problem circuit, but I believe the breaker replacement is going to solve your problem..

Pat.
10 guage wire minmum is required for 30 amp

Most 15 amp breakers are on 14 guage and 20 amp is 12 gauge
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Old 01-17-2022, 11:39 AM   #15
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Because it trips INSTANTLY at home but not at camp grounds, I think itís most likely that you have a grounded neutral in motorhome. Itís a common problem and fortunately one that is very easy to check.



If it is a grounded neutral, opening all breakers in your motorhome wonít keep your house GFIC from tripping. If house GFI trips anyway, you can confirm motorhome neutral is grounded with a multi-meter; or ask shop to check for you. Just takes a minute with OHM meter to confirm if that is indeed the problem. Could be many things that is causing your problem, but I would bet on it being grounded neutral.
With no current flow the GFCI shouldn't trip

Takes a ground fault
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Old 01-17-2022, 11:45 AM   #16
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Agree with Chance and 16ACE27. As mentioned the neutral (white wire) in your RV should not be bonded (connected) to ground (bare copper wire) in your RV. This is only supposed to happen in the pedestal at the campground. A simple way to think of how a GFIC circuit works is that all the current that goes out from the power source on the black wire should go back to the source on the white wire. In a correctly wired system there should not be any current carried by the bare copper wire. If your body comes into contact with the live wire (black wire) for what ever reason and you touch something like a stove that has its chassis connected to the bare copper wire current will flow thru your body back to the source via the bare copper wire. The GFIC circuit breaker senses this current flow in the bare wire by using a differential transformer between the black wire and the white wire. If the current at the center tap of the transformer exceeds about 20 ma the GFIC will trip thus keeping you from being electrocuted. If for some reason current greater than 20 ma is leaking to the bare wire in your RV then the GFIC will trip as soon as you plug into the 115 VAC outlet on your home. This can even be cause by water somewhere causing current to flow to the ground in the RV. It is most likely caused because someone added a device or replaced a device and wired it incorrectly. Folks often make this mistake because they know in there home in the breaker panel that the bare copper and white wire are connected together and think they are basically the same. If you add a second panel of breakers at your home for say a detached garage then the panel used there cannot have the bare and white wires connected together.

Get an ohmmeter and with the power cord from your RV not connected to anything and the generator and inverter off in the RV test the resistance between the round prong on the plug that you plug into your hose for resistance between the other two flat blades. They should not be connected.
In a short summary a GFCI trips when the neautral and hot wire load isn't balanced

Your comments on the secondary panels are spot on
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Old 01-17-2022, 02:31 PM   #17
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With no current flow the GFCI shouldn't trip

Takes a ground fault

Not the way you think. It can, and it did. I covered how and why in another thread.

I give credit to a cousin who’s an electrical engineer who had to show me how the hot lead doesn’t have to have any current at all for the GFIC to trip.

I had this issue, and indeed various GFIC I plugged into tripped even when I had van’s main breaker off.

A GFIC is designed to protect against ground fault, but also trips when it detects a difference in current between hot and neutral, and it doesn’t have to be on hot side. It’s hard to follow and harder to explain, but true.


P.S. — Current flows between neutral and ground wires, hence neutral and hot no longer in perfect balance, causing house GFIC to trip.
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Old 01-17-2022, 05:53 PM   #18
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Not the way you think. It can, and it did. I covered how and why in another thread.

I give credit to a cousin whoís an electrical engineer who had to show me how the hot lead doesnít have to have any current at all for the GFIC to trip.

I had this issue, and indeed various GFIC I plugged into tripped even when I had vanís main breaker off.

A GFIC is designed to protect against ground fault, but also trips when it detects a difference in current between hot and neutral, and it doesnít have to be on hot side. Itís hard to follow and harder to explain, but true.


P.S. ó Current flows between neutral and ground wires, hence neutral and hot no longer in perfect balance, causing house GFIC to trip.
What you said is true it takes an imbalance, same thing I said, if no imbalance then it won't trip, why would it?
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Old 01-17-2022, 05:57 PM   #19
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GFCI outlets don't need a ground wire to function properly

Because they look at the balanced load

I have installed a lot of them in old-wired houses with-out grounds
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Old 01-17-2022, 06:01 PM   #20
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Not the way you think. It can, and it did. I covered how and why in another thread.

I give credit to a cousin whoís an electrical engineer who had to show me how the hot lead doesnít have to have any current at all for the GFIC to trip.

I had this issue, and indeed various GFIC I plugged into tripped even when I had vanís main breaker off.

A GFIC is designed to protect against ground fault, but also trips when it detects a difference in current between hot and neutral, and it doesnít have to be on hot side. Itís hard to follow and harder to explain, but true.


P.S. ó Current flows between neutral and ground wires, hence neutral and hot no longer in perfect balance, causing house GFIC to trip.
We probably don't need to get technical with this but what you are saying is true when there is fault, therefore the current flow between ground and neutral occurs, otherwise nothing happens

Were almost on the same page but not quite
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