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t-smith's avatar
t-smith
Explorer
May 04, 2016

Shore GFI tripping when Inverter circuit is on

I've had my TT unplugged for about a year. Last week, I plugged it into a 20amp GFI circuit. All breakers on in TT. Turned on AC, furnace, etc - everything was good. Had it plugged in a week like that, unplugged for a couple days as I was changing tires, so I had to move the TT a couple feet forward and back. Yesterday, I plugged back in and the shore outlet (GFI) tripped. I've gone into the TT and turned off all breakers, and reset the shore GFI. Then, turned on each breaker in TT 1 at a time. It's the breaker that feeds the inverter for the 12v system.

Now, no worries when plugged into a non gfi. I measured the voltage on hot/ground and hot/neutral and when the inverter breaker is off, they are identical. When it's on, they differ by about 0.4-0.6 volts.

I've read that some inverters can draw unequally, and that GFI's are sensitive, so don't use - but what has me wondering ig something isn't wrong is... it worked fine the whole week before....

Thoughts? I never noticed, but are the 30amp plugs on a GFI circuit at campgrounds?
  • t-smith wrote:
    Gordon,

    This is the TT's inverter system. Not a system on my house.


    Yes, let me rephrase, whole-coach?
  • Since the inverter is fed by the shore power, you might try to use a surge protector which should equalize any fluctuation or unsteady flow. This will also correct a faulty GF feed. (usually):B
  • Gordon,

    This is the TT's inverter system. Not a system on my house.
  • Typically what upsets a GFI in use with an inverter is the neutral-earth isolation relay... if this is a whole-house type inverter with built in transfer switch.

    My Magnum has two or maybe three relays in it, one for hot, one for neutral and one for neutral-earth isolation. If they don't all switch exactly at the same time, the GFI might think there's an imbalance and trip.

    As least, that's my diagnosis of what's going on.