Growatt SPF trips GFCI occasionally.

eXodus

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I have a Growatt SPF 3000TL LVM and installed it in a RV. It's working great, aside from one little issue.
Input GFCI trips occasionally.

all-in-one-rv-system-v2-png.63255


When I'm at home I plug in the RV with an adapter into an exterior 20A outlet (reduced the charging rate) which is protected by an GFCI outlet.
After a few hours (2-15hrs), the GFCI trips randomly. It resets easy no issue.

Inverter switch on - I've disabled all circuits in the RV at that breaker panel - and it still trips.
Inverter switch off - plugged in (so it's still charging the batteries) it's not tripping the GFCI.

Was wondering if there is a setting in the inverter, what could prevent that behavior. Or if the inverter has a potential fault.

It's not happening in RV parks with the non GFCI 30A outlet there. That would be my alternative plan to just get a regular RV outlet installed. But since there is some sort of Ground fault potential - I wanted to check here first. (and I got a new GFCI outlet ordered since the old one is 20+ years old and I'm not trusting it)

Further I got the feeling that as soon as the I plug it in - it goes in AC bypass mode - even with setting 01: SBU
 

FilterGuy

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Was wondering if there is a setting in the inverter, what could prevent that behavior. Or if the inverter has a potential fault.
Do you know if it occurs when the inverter is switching from Line power to battery power (or visa versa)?

Growatt recently made a change to address a problem with how it handles Neutral-Ground bond, but older models did not handle this very well.

Based on your diagram, I am pretty sure that when powered from the battery, your AC is floating but when powered by the line the AC 'sees' the N-G bond from the line.

Take a look at this:
1638400820505.png

You could start with just the jumper between AC Neutral IN and AC Neutral OUT to see if the GFCI pops any more.

However, just doing the jumper still leaves the AC-out floating if the system is not plugged into shore power. To ensure the AC out is never floating, the relay needs to be added.
 
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eXodus

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You could start with just the jumper between AC Neutral IN and AC Neutral OUT to see if the GFCI pops any more.
that's a good idea an easy to try. I've measure the other day - and they seemed to be contacted internal. But since I don't know how good that connection is - jumper shouldn't hurt.

Do you know if it occurs when the inverter is switching from Line power to battery power (or visa versa)?
It's mainly in line mode during the evening hours / night.
Like I said - when the inverter switch is turned of - the GFCI doesn't trip (as frequently, ever other day or so.)

Thanks for the Diagram - I understand that without the relay there is no neutral ground bonding when the inverter is turned on - This is clearly a safety hazard while on Island mode. - but I don't understand what that should help an upstream GFCI - It's opening the circuit of it.


My other guess is since - it takes some time to trip - there is a neutral or ground loop in the RV, somewhere in the miles of wiring where I got a small leak current.
 

eXodus

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You could start with just the jumper between AC Neutral IN and AC Neutral OUT to see if the GFCI
I got the jumper installed - and plugged it in - didn't trip in the short term, neither in charging or bypass mode.
But that took usually a few hours to happen anyhow. I never had a instant trip.

Since it is weekend, I installed a new GFCI breaker for my exterior outlets - now the RV is plugged in for 24hrs and didn't trip yet.

Hopeful so far, don't know if it's because of the jumper or the new GFCI.
If I get 48 hrs without tripping that would be a major improvement.
 

gabrielpc1190

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Did it trip again? or it's finally solved?
It happened to me too, but the GFCI was downlink the inverter.
 

eXodus

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Did it trip again? or it's finally solved?
It happened to me too, but the GFCI was downlink the inverter.
New GFCI outlet solved the issue.

Never had it tripped again. Tried another old GFCI outlet in my house, same thing. Apparently 20 years of age and being cheaper builder quality makes GFCI more sensitive.
 

eXodus

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Have not heard that yet.

Is this for GFCI in general or only outlet type? Back in Germany we had GFCI only at the breaker panels and never at the outlet.

Those things are good for 30 years
 

FilterGuy

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Have not heard that yet.

Is this for GFCI in general or only outlet type? Back in Germany we had GFCI only at the breaker panels and never at the outlet.

Those things are good for 30 years
I had heard this about the GFCI outlets.....
 
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