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shabrown1 avatar image

Connecting to 120 shore power trips breaker

Have a Multiplus 12/120/3000 with 4-100 amp hour Lithium batteries in series installed in our fifth wheel trailer. Everything has been working great and as it should, but I recently tried to plugin to a standard 120 wall outlet just to trickle charge the batteries while parked in a friends driveway and it would trip the breaker. I tried turning off everything via my breaker panel in my trailer that wasn't necessary to see if it was a load issue...still trips. I also played around with the current limiter settings on my victron digital multi control...nothing made a difference. Multi control was set to charger only. Has anyone else had any issues like this? Maybe something else I can look into to try. Please advise? Thank you in advance :)

Multiplus-IILithium BatteryshorepowerDigital Multi Control
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I had a similar problem. I could make it work by unchecking the Relay check box on the Inverter tab in VEConfig. It made me nervous though because it meant there was a Neutral or ground problem... It turns out that I had all the Neutrals tied together (Lots of Multipluses are wired this way. If you don't try to run with a GFI protected shore power you won't notice.). My solution was to isolate the AC out 1 and AC out 2 Neutrals from the rest of the Neutrals. I did this by cutting the Neutral bus bar in the 5th wheel panel in half. One half for the AC out 1 and 2 and the other half for the AC in and second phase Neutrals. (I was set up for 50A shore power.) I left the grounds all tied together. After making this change, I could run from GFI protected shore power with the Relay check box checked.

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ben answered ·

First thing to check is whether it’s a GFI breaker, or if you’re tripping a GFI-equipped receptacle (rather than the breaker proper).

If not those, we need a lot more detail, including things like: how long does it take to trip? What happens if you power off the Multiplus completely? Do you have circuits in your RV upstream of the Multiplus? What current limit setting did you set that still tripped it?

Charger-only probably doesn’t matter at all for this issue. It can still draw a lot of current, or not be the issue at all, when it’s set to only be a charger.

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Hi Ben. Yes my apologies it trips an outdoor gfi outlet. Seems to trip once I turn my controller from off to charge only. I have also noticed that once I hookup my trailer to tow and plugin my 7 pin connection I don’t get any battery charging from that during a tow. For both a shore power and towing application I have tried setting the current limiter to zero and also at different levels up to 10. Still trips and no 7 pin charging. When I am hooked up to...the lowest having been 20 amp service. I get charging and no issues. Just seems to be at the lower 15 amp 120 range I have these issues. Wonder too if maybe there is a setting in the Multiplus setup where maybe I have a minimum charge input set too high to not allow for the lower amp service? Could that be a possibility? Thx!

It's most likely that you have a ground wiring issue causing the GFI to trip.

If so, that's a fundamentally unsafe setup, and you should get it diagnosed and fixed. It's probably working on other outlets because they don't have GFI protection.