Community Forums

mischmerz · 11-25-2020, 06:43 PM

I have a Winnebago Outlook where the shore power cable plugs into the generator receptacle when not in use. Everything works as it should. Shore power / generator power runs through an automatic transfer switch that connects/disconnects both, hot and neutral. My new inverter (Renogy, 2 KW) has a built in GFCI that pops when the shore power cable is plugged into the generator receptacle (generator NOT running), it works fine when the generator cable is not plugged in.

Somewhere .. something is not right. Where should I start to investigate?

Thanks for your help.

okcnewbie · 11-26-2020, 09:29 AM

If you have a transfer switch it seems odd that you would ever "plug your shore power cable" into the gen. Try not doing that maybe. A schematic might help me better understand though.

Persistent · 11-26-2020, 09:51 AM

Circuit breakers trip when there is too much current.
GFI (Ground Fault Interrupter) trip when there is a "Ground Fault".

Assuming your GFI trips (not circuit breaker) and you have a transfer switch, you should not plug the shore power cord into the generator outlet. The transfer switch takes care of switching from shore to gen.

Some RV's do not have transfer switches. Plugging the shore power cord into the generator is how power source is switched.

When on shore power, your TT 120 volt system ground should not be grounded to the frame ground.

When using a generator, the system ground should be grounded to the frame.

The transfer switch takes care of connecting the frame ground. Not letting this happen can cause a Ground Fault Interrupter to trip.

I wish you good luck and happy trails ahead!

Persistent · 11-26-2020, 09:55 AM

Please post year, make, and model of your RV in your profile and possibly add it to you signature line. Help given is likely to be more accurate then.

Posting make and model of appliances like a transfer switch when asking questions about them is also much more useful.

Gary RVRoamer · 11-26-2020, 10:35 AM

You would not have to plug the shore cord into a genset receptacle if it has an auto-transfer switch, so either you are misunderstanding your equipment or using it wrong. Please take another look at your system, cause it probably does not have an auto-transfer switch.

The GFCI (Ground Fault) trip indicates that the genset wire polarity is different than the inverter. Possibly neutral or hot are reversed in one or the other.

Jkwilson1989 · 11-26-2020, 12:26 PM

Likely the neutral is being connected to ground when plugged into the generator. That is a second thing that will cause a GFCI to trip.

153stars · 11-26-2020, 02:59 PM

What above post said....
Look for neutral and ground bonded on RV breaker panel. It really should not be because RV panel is classified a distribution panel if and when its plugged in to an outside AC panel.But many have found them bonded. Look for all Neutrals to neutral bar grounds to the ground bar and no jumper joing them.

twinboat · 11-26-2020, 03:33 PM

The RV breaker panel should not be, and probably is not bonded ( ground and neutral tied together ), but the generator will be, since it becomes the source of power.

If your inverter GFCI is tripping, you have something back feeding. There should be no connection to your shore cord.

Send us some info on your equipment and a sketch of how you wired it in.

mischmerz · 11-27-2020, 07:44 AM

Thanks for you answers. We are talking about a 2008 Winnebago Outlook. The shore power cable is used for both, shore power and generator. When not connected to shore power, the cable is plugged into the generator outlet.

The motor home was not originally equipped with an inverter. I added a transfer switch (Go Power) to switch from shore power / generator to inverter. If the shore power cable is plugged into the generator outlet, the inverter will complain with a GFCI error. When the shore power cable is NOT plugged in, everything works fine.

As I understand it, the inverter is internally bonded. The generator is probably too. What puzzles me is the fact that the transfer switch disconnects both, the hot and the neutral, so it should break the generators bond.

But it obviously doesn't.

Michaela

egwilly · 11-27-2020, 07:56 AM

Please take some time to read about ground-neutral bonding at the no shock zone. Rv's are different than houses in regards to grounds.

This guy knows his stuff and has helped me in the past.

Generator Ground-Neutral Bonding - No~Shock~Zone

http://noshockzone.org/rv-electrical...oubleshooting/

wolfe10 · 11-27-2020, 08:13 AM

Quote:

Originally Posted by mischmerz

Thanks for you answers. We are talking about a 2008 Winnebago Outlook. The shore power cable is used for both, shore power and generator. When not connected to shore power, the cable is plugged into the generator outlet.

The motor home was not originally equipped with an inverter. I added a transfer switch (Go Power) to switch from shore power / generator to inverter. If the shore power cable is plugged into the generator outlet, the inverter will complain with a GFCI error. When the shore power cable is NOT plugged in, everything works fine.

As I understand it, the inverter is internally bonded. The generator is probably too. What puzzles me is the fact that the transfer switch disconnects both, the hot and the neutral, so it should break the generators bond.

But it obviously doesn't.

Michaela

That is a somewhat unusual use of an ATS which will account for many of our posts. Normally ATS's select between SHORE POWER and GENERATOR only. In this standard configuration, one does not change plugs based on source-- it is hardwired and automatic.

And part of your ATS's function (to select inverter) is more usually handled inside the inverter/charger (one unit, not two separate ones) by an internal ATS which selects and "passes through" 120 VAC when it receives it from either shore power or generator.

mischmerz · 11-27-2020, 10:15 AM

Not every inverter is able to sense line voltage and disconnect accordingly. I don't even know if my Renogy inverter would do that. This is why IMHO an ATS is much safer. The other reason for an ATS is simply to disconnect the charger if running on inverter. You wouldn't want to charge your batteries while you are powering the inverter from your batteries.

Edit: If have two different units: A converter/charger and an inverter.

In other words: An ATS has it's place in a setup like mine.

twinboat · 11-27-2020, 11:04 AM

I have basicly the same setup. I added a standard RV 30 amp ATS to switch some circuits between shore/generator OR inverter power.

I set it up that the shore / generator power goes to the generator input of the new ATS. That way, anytime 120 volts is there is it powers thru. ( Generator is priority on ATS s ).

When there is no shore/gen power, the ATS defaults to the inverter and powers the circuit.

If yours isn't wired that way, basicly inputs backwards, try it. May fix the issue.

mischmerz · 11-27-2020, 11:08 AM

I think I need to explain a bit more in detail. The inverter runs the motor home just fine. A line tester says everything is ok, the inverter's GFCI does not trip.

The inverter is internally bonded.

When I turn off the inverter and start the generator, power is supplied and everything works fine too. The line tester is still happy.

As I mentioned before - the generator has a dedicated outlet in a compartment and that's where one is supposed to plugin the shore power cable when not on shore power.

When the generator is NOT running, an automatic transfer switch disconnects the live and the neutral wire, ground however remains connected.

When I plug in the shore power into the generator outlet, the inverter's GFCI trips. In other words: By connecting the ground to the generator, I create a fault even though neutral and live are disconnected via transfer switch.

This doesn't make sense and it confuses the hell out of me.