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Split-phase Victron pops upstream 120v GFCI

cinergi

1.21 Jigawatts
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This is an advanced configuration ... but my RV is split-phase (2 Quattro 5k's) configured such that I can still connect to 120v shore ("switch as group" is turned off) using a typical RV dog-bone adapter. While that presents 120v to both L1 and L2, it's the same "phase" so the L2 Victron ignores the input. However, I always immediately trip the shore's GFCI in the outlet (multiple campgrounds now) as soon as the L1 Quattro connects to shore... from what I understand, that means that there's a difference in the current between hot and neutral. And I'm not sure how that's possible. One quattro (L1) is configured to bond neutral-ground when disconnected from shore. Would appreciate thoughts on how to diagnose, given the immediate tripping that occurs and the probable tiny difference in current between hot and neutral (such that attempting to measure for where leakage is occurring would seem impossible). Note that I do have a 240v load (mini-split) ... I'm trying to wrap my head around the current flow in that case .. since L1 is coming from shore and L2 is coming from the inverter. Neutral is not used by the mini-split (not sure if it's physically connected, however).

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If there are 2 neutral ground bonds then you will have current flow on the ground wire.
That is a bad thing.
Do you have an amp clamp?
 
If there are 2 neutral ground bonds then you will have current flow on the ground wire.
That is a bad thing.
Do you have an amp clamp?

There's only 1 bond (as configured; and only when disconnected from shore). I do have an amp clamp ... thus far I've assumed my ground current is too small for it to see, but the duration I'm connected to shore before GFCI trips is also extremely short so I'm not expecting to catch anything concrete.
 
You've wired best practices on AC side? Identical length neutrals?

Not sure about stringing your ground the way you have, but that's probably more about my ignorance. I know that method is desirable in some cases.

Q1 = N-G bond only when NOT on shore power?
Q2 = N-G bond never?

You sure neither is ever engaging when on shore?

The whole L2/L1 shorting and Q2 "ignoring it" bothers me. Have you tried disconnecting L2?
 
There's only 1 bond (as configured; and only when disconnected from shore). I do have an amp clamp ... thus far I've assumed my ground current is too small for it to see, but the duration I'm connected to shore before GFCI trips is also extremely short so I'm not expecting to catch anything concrete.
If you disconnect the ground at source does the gfci stop tripping?
Be careful that you don't become part of the ground path.
 
You've wired best practices on AC side? Identical length neutrals?

Not sure about stringing your ground the way you have, but that's probably more about my ignorance. I know that method is desirable in some cases.

Q1 = N-G bond only when NOT on shore power?
Q2 = N-G bond never?

You sure neither is ever engaging when on shore?

The whole L2/L1 shorting and Q2 "ignoring it" bothers me. Have you tried disconnecting L2?

Yeah same length. And correct on bonding.
I'm not sure I have a way to verify whether bonding is on/off when on shore.

I am contemplating disconnecting L2 while on 120v shore to see what happens ... I just have to remove everything from the basement to get at those connections :(
 
If you disconnect the ground at source does the gfci stop tripping?
Be careful that you don't become part of the ground path.

Hm, good idea - I can try that too if I spent the time clearing access to the wiring to do so.
 
Hm, good idea - I can try that too if I spent the time clearing access to the wiring to do so.
The other thing you can do is tap a non gfci circuit and check for current on the ground wire.
If there are parralel n/g bonds the current should be shared nearly equally with neutral.
Of course you want an unbalanced load.
 
The other thing you can do is tap a non gfci circuit and check for current on the ground wire.
If there are parralel n/g bonds the current should be shared nearly equally with neutral.
Of course you want an unbalanced load.

Yeah, no access to my own 120v 20 amp plugs.. but you just made me realize that the campground here has a 30 amp plug and I think no GFCI on it, so I could probably use that.
 
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