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TomAndPeg · 11-11-2018, 04:26 PM

I recently encountered shore power pedestals with 30A GFCI breakers. One was at an Illinois State Park and the other at a Minnesota State Park. On both occasions, when I plugged my 50A couch into the pedestal via an adapter, I could not put shore power to my 3KW inverter/charger without tripping the pedestal GFCI breaker. Of course, without the charger portion of my inverter available, I could not recharge my batteries.

Note that this power scenario has not been a problem for me with non-GFCI 30A power pedestals, either before or since. Also, my 3KW inverter/charger works great, but it is 2001 technology.

I did some online research and found that this is becoming a significant problem for the marine industry. Boaters may not be able to use updated shore power that employs GFP (ground fault protection), a 2011 NEC mandated technology for marinas and shipyards similar to GFCI. Apparently the power up sequence of an inverter/charger can appear to the pedestal GFCI as a voltage leak, so TRIP.

One article even suggested going through a myriad of power up sequence scenarios from all breakers OFF, but none of those worked unless I left the inverter/charger OFF. (At one park, a tech even replaced the 30A GFCI breaker at the pedestal, but that did not help.) He also said the problem I was experiencing was all too common with their 30A GFCI, but not their 50A GFCI pedestals. Unfortunately, I was not able to test the latter scenario.

My question is, short of investing in a very expensive Isolation Transformer (or other equally expensive changes to the perfectly good power systems on my rig), does anyone have a reasonable solution for this? I hate to avoid state parks in my travels, but apparently many states are early adopters of 30A GFCI pedestal outlets.

Jthigh · 11-11-2018, 04:33 PM

I have the same issue with my system. Everything in my coach is original and never have any issue with non-gfi service. If plugged into a GFI outlet it trips as soon as my inverter/battery charger comes online to charge house batteries. I plan to investigate solutions this winter but unable to provide any solutions at this time.

twinboat · 11-11-2018, 04:51 PM

Pick up a standalone converter charger.
Something like a GoPower 55 will handle the charging. Just wire it to the battery bank and plug it in. Leave the inverter/charger off.

nothermark · 11-11-2018, 07:21 PM

The problem is the clueless person who specified GFCI's for RV or Marine power connections. They are *NOT* the correct answer as the shore cord is part of the distribution system not a load branch circuit.

TomAndPeg · 11-11-2018, 07:24 PM

Quote:

Originally Posted by twinboat

Pick up a standalone converter charger.
Something like a GoPower 55 will handle the charging. Just wire it to the battery bank and plug it in. Leave the inverter/charger off.

Thanks! I think this is a good workaround for the batteries, but there is an additional problem: the inverter also routes AC power to a bunch of outlets, regardless of the power source. No inverter also means no power to those outlets. That said, in the absence of a better solution, I think I will invest in a stand-alone charging system as a hedge.

Rkesselus · 11-11-2018, 08:03 PM

Most building codes require a GFCI breaker for any 20 amp circuit so that is what happens when using a cheater( adaptor) using a 30 amp RV plug and a 20 amp plug to get you 50 Amps. The transfer switch causes the GFCI to read an extra ground and trips. I carry a non GFCI duplex plug and change it out if we stay in one spot for any length of time.

Props2 · 11-11-2018, 09:53 PM

I can see them wanting gfi's for the 20a circuit. For the 30's, I dont know why they dont use EPD breakers that have a 30ma threshold. I am thinking the rfi suppression filters leak enough to trip the 5ma gfi's? But that's just a guess. I know its all about personal protection,but geez, how many people are plugging hand held appliances in a 30a. Its all about AHJ's.(authority having jurisdiction)

So yes....yes, a transformer would be needed to add to your arsenal or some new fangled device on the market.

Jthigh · 11-12-2018, 05:42 AM

Quote:

Originally Posted by nothermark

The problem is the clueless person who specified GFCI's for RV or Marine power connections. They are *NOT* the correct answer as the shore cord is part of the distribution system not a load branch circuit.

Agreed, as a former technician the main power distribution panel is in the coach not the pedestal.

hypoxia · 11-12-2018, 06:03 AM

I have had that problem when I first connect and the charger starts a bulk or equalizing charge. I have found if I leave everything but the charger off for 15 minutes or so when the charger reduces its amp load it resolves the problem. The other work around I do if I want A/C immediately is turn the charger off until the A/C load is reduced.

TomAndPeg · 11-12-2018, 07:09 AM

Quote:

Originally Posted by Rkesselus

Most building codes require a GFCI breaker for any 20 amp circuit so that is what happens when using a cheater( adaptor) using a 30 amp RV plug and a 20 amp plug to get you 50 Amps. The transfer switch causes the GFCI to read an extra ground and trips. I carry a non GFCI duplex plug and change it out if we stay in one spot for any length of time.

Thanks Rkesseslus: I actually thought about making a run to Home Depot to buy a 30A non-GFCI breaker to swap out, but went to another campground instead. I have no doubt that any state park would frown on doing a breaker swap. And if I did it, I would surely forget to re-swap when I left.

TomAndPeg · 11-12-2018, 07:14 AM

Quote:

Originally Posted by hypoxia

I have had that problem when I first connect and the charger starts a bulk or equalizing charge. I have found if I leave everything but the charger off for 15 minutes or so when the charger reduces its amp load it resolves the problem. The other work around I do if I want A/C immediately is turn the charger off until the A/C load is reduced.

Thanks, hypoxia. I'm not sure if I can turn the charger portion of the inverter OFF/ON, but if I can I'll certainly try this.

TomAndPeg · 11-29-2018, 09:30 PM

Quote:

Originally Posted by thomaspryan

Thanks, hypoxia. I'm not sure if I can turn the charger portion of the inverter OFF/ON, but if I can I'll certainly try this.

As a follow-up, it turns out that I can run my inverter with the charge function OFF. Next time I encounter a 30A GFCI, I will try Hypoxia’s method of power-up the inverter functions. If that doesn’t work, I’ll invest in an independent charging system.