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Electrical Issue

LaTriker
Explorer
Explorer
I have a new class c with 30 amp plug. I can plug into 30 amp with no problem. Can plug into 20 amp non GFI with no problem, but I trip every 20 amp GFI plug that I plug into. Do I have a problem that needs attention?
15 REPLIES 15

Harvard
Explorer
Explorer
Switching Mode Power Supplies and GFCIs

START QUOTE:
As explained earlier, RF noise filtration circuits in SMPS (Switching Mode Power Supply) generate intentional Earth Leakage Current. SMPS are used extensively as DC power sources in modern day electrical / electronic devices e.g. Audio / Video / Computing devices, power supplies, battery chargers etc. A single GFCI outlet / GFCI breaker may be serving multiple SMPS loads and therefore, will be sensing the sum of all the Earth Leakage Currents and, if the sum is > 4 to 6mA after connecting this unit, the GFCI will trip.
END QUOTE:

cavie
Explorer
Explorer
77rollalong wrote:
cavie wrote:
77rollalong wrote:
I think this is a problem with the way the fuse box is wired in the RV's in that the white wire is grounded inside the fuse boxes, so if there is any current passing back through the ground, the gfi will trip as you now have both the white and the ground that can pass current rather than just the White..


Nope. The white neutrals are not connected to the grounds. This doesn't happen until it gets back to the campground main service. Pedestals and RV's neutral are floating. and not connected to the grounds.

GFI's are special built to detect a 5 MA leak hot to neutral and neutral to ground.

Remove your panel cover and have a look inside. They have separate ground bars. The grounds are bonded to the frame of the RV.

yes look inside the back of the fuse box, you will find that the white wires are connected to a common bus bar that is attached to the metal case of the fuse box, and a separate buss bar for the grounds, that is also connected to the case too..
2011 Keystone Sprinter 323BHS. Retired Master Electrician. Retired Building Inspector.

All Motor Homes are RV's. All RV's are not Motor Homes.

cavie
Explorer
Explorer
77rollalong wrote:
cavie wrote:
77rollalong wrote:
I think this is a problem with the way the fuse box is wired in the RV's in that the white wire is grounded inside the fuse boxes, so if there is any current passing back through the ground, the gfi will trip as you now have both the white and the ground that can pass current rather than just the White..


Nope. The white neutrals are not connected to the grounds. This doesn't happen until it gets back to the campground main service. Pedestals and RV's neutral are floating. and not connected to the grounds.

GFI's are special built to detect a 5 MA leak hot to neutral and neutral to ground.

Remove your panel cover and have a look inside. They have separate ground bars. The grounds are bonded to the frame of the RV.

yes look inside the back of the fuse box, you will find that the white wires are connected to a common bus bar that is attached to the metal case of the fuse box, and a separate buss bar for the grounds, that is also connected to the case too..


NO SIR. The neutrals are not connected to the metal case or to the frame. In fact most RV panels are made of plastic. The grounds are connected to the frame of the RV but not the neutrals. neutrals.
2011 Keystone Sprinter 323BHS. Retired Master Electrician. Retired Building Inspector.

All Motor Homes are RV's. All RV's are not Motor Homes.

77rollalong
Explorer
Explorer
cavie wrote:
77rollalong wrote:
I think this is a problem with the way the fuse box is wired in the RV's in that the white wire is grounded inside the fuse boxes, so if there is any current passing back through the ground, the gfi will trip as you now have both the white and the ground that can pass current rather than just the White..


Nope. The white neutrals are not connected to the grounds. This doesn't happen until it gets back to the campground main service. Pedestals and RV's neutral are floating. and not connected to the grounds.

GFI's are special built to detect a 5 MA leak hot to neutral and neutral to ground.

Remove your panel cover and have a look inside. They have separate ground bars. The grounds are bonded to the frame of the RV.

yes look inside the back of the fuse box, you will find that the white wires are connected to a common bus bar that is attached to the metal case of the fuse box, and a separate buss bar for the grounds, that is also connected to the case too..

Flute_Man
Explorer
Explorer
GFIโ€™s are to prevent shocks and electrocutions.
Please get it fixed. It is NOT normal for an RV to trip them.
You definitely have a fault in the RV.
Jerry Parr
602-321-&141
Jerry Parr
05 Mandalay 40B
Cat C7 350
04 Honda CR-V
Ham Radio K7OU
Retired EE
Jrparr32@gmail.com
602-321-8141
Full-timer

cavie
Explorer
Explorer
77rollalong wrote:
I think this is a problem with the way the fuse box is wired in the RV's in that the white wire is grounded inside the fuse boxes, so if there is any current passing back through the ground, the gfi will trip as you now have both the white and the ground that can pass current rather than just the White..


Nope. The white neutrals are not connected to the grounds. This doesn't happen until it gets back to the campground main service. Pedestals and RV's neutral are floating. and not connected to the grounds.

GFI's are special built to detect a 5 MA leak hot to neutral and neutral to ground.

Remove your panel cover and have a look inside. They have separate ground bars. The grounds are bonded to the frame of the RV.
2011 Keystone Sprinter 323BHS. Retired Master Electrician. Retired Building Inspector.

All Motor Homes are RV's. All RV's are not Motor Homes.

77rollalong
Explorer
Explorer
I think this is a problem with the way the fuse box is wired in the RV's in that the white wire is grounded inside the fuse boxes, so if there is any current passing back through the ground, the gfi will trip as you now have both the white and the ground that can pass current rather than just the White..

houstonstroker
Explorer
Explorer
Common problem, probably nothing wrong. GFCI RVs do not like to be plugged into GFCI outlets.
2016 Dynamax Force HD Super C

LaTriker
Explorer
Explorer
DownTheAvenue, I like your answer. Iโ€™ll go with it.

DownTheAvenue
Explorer
Explorer
Common problem. My last three RV's did the same thing. I am not an electrical engineer, but I think somehow the GFI outlets and RV's don't like each other. I would not worry about it.

DrewE
Explorer II
Explorer II
Harvard wrote:
This raises the question, why are 30A pedestals not protected by GFCIs. I believe it is because there could be a lot of false trips due to the normal leakage current expected from any individual RV AC distribution of capacitance. JMO.


I suspect it's just the NEC editors haven't gotten around to thinking about it yet. 30A GFCI circuit breakers are available. (One could reasonably ask why 50A RV pedestal outlets are likewise not GFCI protected; two pole GFCI breakers do likewise exist, though they are not exactly inexpensive.

I don't think too many RVs cause false GFCI trips due to expected capacitance or leakage in the electrical system (though that is indeed a possibility sometimes). Rather, I think most trips are caused by people having wiring faults (such as neutral/ground faults) or other problems they don't know about, problems that are a potential hazard. Fridge or water heater elements that are breaking down and leaking current to ground are one distinct possibility. I don't have any actual data to back this up, however.

If GFCIs were to be required, it may possibly make sense to have the fault current trip limit a little less sensitive than for standard 20A GFCIs.

Harvard
Explorer
Explorer
This raises the question, why are 30A pedestals not protected by GFCIs. I believe it is because there could be a lot of false trips due to the normal leakage current expected from any individual RV AC distribution of capacitance. JMO.

cavie
Explorer
Explorer
try this test. turn off the gfi circuit in your RV. plug into a GFI shore power and let us know if it trips.
2011 Keystone Sprinter 323BHS. Retired Master Electrician. Retired Building Inspector.

All Motor Homes are RV's. All RV's are not Motor Homes.

Nv_Guy
Explorer III
Explorer III
Short answer is yes you do.
Assuming you have a good 30-20 adapter, experience has taught me that 90% of the time it is a water heater element that has failed, next is the electric element in the refrigerator.
Quick troubleshooting is to turn the water heater breaker off and unplug the refrigerator, then plug the coach back into the GFI and see if it trips.
If the GFI trips with refrigerator unplugged & WH breaker off time to look at power cord / adapter & overall wiring.
If not, turn on the WH breaker and see if the GFI trips. If not plug the refrigerator in and again see if the GFI trips.