MPPT 60 ground fault problem

Rance

I recently added a second array and Schneider MPPT60 to my off grid PV system (Schneider 6848 inverter, SCP, AGC), 48 V battery bank.   Problem is that either the old array & its MPPT 60 or new array & its MPPT 60 work fine independently.  But together I get a ground fault error.  Each array kicks out about 2800 watts and about 100 volts so are well within spec for the MPPT60s.     Yes, the GF fuse was removed from the new MPPT 60 so there's only one and it tests good and I've tried swapping it between the two MPPT60s.   I've completely disconnected the PV lines into the terminals on both MPPT 60s and still get a ground fault so it can't be the arrays, combiners/breakers. And both combiners have surge protectors.    I've tested the battery disconnect breaker box and can't find any voltage leaks with a DMM.  The battery is not bonded to ground at any place in the system other than via the GF circuitry in the MPPT 60s, both of which are solidly grounded, as are all components to the system ground.

At this point I'm ready to bypass the GF circuitry in both MPPT60s by moving the jumpers.    All thoughts/ideas/comments will be appreciated!

Thanks!

Dave Angelini

Have you checked with Schneider for possible warranty or fix? 

Rance

The inverter and one of the two charge controllers are long out of warranty.  And unfortunately I've found Schneider's tech support decidedly unhelpful in the past.   

Since both arrays and controllers work fine independently and only see a ground fault when I try to put both in simultaneous operation  it must be some voltage differential between the two controllers, and it must also be on the battery side because it still happens with the arrays totally disconnected from their respective controllers.   I'm testing with a fairly decent  Klein DMM, but could the fault be below the sensitivity level of the meter?  Do you see any problem if I simply bypass the ground fault circuitry and leave the system without ground fault protection?    Thanks!

Dave Angelini

Schneider has upped their game in support for non pro's and will respond. You should reach out.

I would not bypass the the GFCI as it has save a few of my client systems from lightning surges. It is a huge plus for Offgrid in my opinion.

I think they would help you if you are reasonable on the phone with them. Attitude counts ! 

Got to go !   https://solar.se.com/us/en/support/