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CODE-3 Ground Fault on Inverter after EV charging installed?

Posted: Fri Nov 28, 2025 10:29 am
by leSoleiletlaMer
Hello, am super happy to find this community of experts! Hope I can request some help.

We have 10 PV panels connected to an EP11 battery via an H1-G2 inverter installed in April and have been really happy with the system. We had a Ohme Home Pro EV charging point installed on Monday and ever since the app and inverter from panel have been reporting a CODE-3 Ground Fault that hasn't cleared down by a power off reset of the inverter/battery.

None of the RCD trips appear to be flipped and all the home electrics including the charging point appear to be working as expected, except the PV no longer charges the battery, so I've set a forced time charge to add some overnight energy (we're on Octopus Intelligent Go)

I am hoping the electrician is able to get back to check the connections sometime today, would be useful to know if there are any "gotchas" to look for - added some pictures of what the install looks like if that helps.
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Re: CODE-3 Ground Fault on Inverter after EV charging installed?

Posted: Fri Nov 28, 2025 11:43 am
by Dave Foster
A code 3 ground fault suggests that there may be a problem on the panel DC wiring - has there been any recent damage to your panels, possible water ingress ?

As a test you should be able to isolate the PV on the switch under the inverter and the fault should no longer be present - then it’ll be good old fault finding and checking for the electrician, possibly loose MC4 connectors or similar.

Re: CODE-3 Ground Fault on Inverter after EV charging installed?

Posted: Fri Nov 28, 2025 1:22 pm
by leSoleiletlaMer
Hi Dave , thanks for the reply, no changes other than installing the EV charger on Monday, after which the errors begain to show. Seems more than coincidental as they are both wired to the PV consumer unit :?

Will do as suggested and get the electrician back with a tester to see if can find any loose connections.
Cheers
David