EG4 6000EX parallel Error 72 only during peak solar

[Bfreemannh]

I am plagued with a current sharing fault. Had a single unit running for over a year. Just added a 2nd parallel 6000ex and it ran great for a week until the sun came out with some intensity. I have two arrays (one per 6000ex), each max at about 210v at 3.7k before it will fault with error 72 (without fail). If I turn off the slave inverter and just use it as a solar charger, no issues. Battery SOC dose not appear to have any impact. It only faults during peak solar production. Since it is an off-grid system, I am also charging via the line in with a 15k low distortion propane generator with the inverters set for 30a AC each, without any faults.

Actions taken:
Updated to latest firmware (inverters only)
Reseated serial cables and red/black current cables
Shortened and extra twist added to current cables
Made AC output cables same length
Checked all connections
The output voltages seem to be within reason (115-120vac)

System:
Off-grid only
2, eg4 6000ex
6, eg4 LL V2 batts
20, 455w Solarever panels (two sets of five using a Y-branch connector, on each inverter)

 

[Bfreemannh]

Please help.

 

[EG4_Jared]

I am plagued with a current sharing fault. Had a single unit running for over a year. Just added a 2nd parallel 6000ex and it ran great for a week until the sun came out with some intensity. I have two arrays (one per 6000ex), each max at about 210v at 3.7k before it will fault with error 72 (without fail). If I turn off the slave inverter and just use it as a solar charger, no issues. Battery SOC dose not appear to have any impact. It only faults during peak solar production. Since it is an off-grid system, I am also charging via the line in with a 15k low distortion propane generator with the inverters set for 30a AC each, without any faults.

Actions taken:
Updated to latest firmware (inverters only)
Reseated serial cables and red/black current cables
Shortened and extra twist added to current cables
Made AC output cables same length
Checked all connections
The output voltages seem to be within reason (115-120vac)

System:
Off-grid only
2, eg4 6000ex
6, eg4 LL V2 batts
20, 455w Solarever panels (two sets of five using a Y-branch connector, on each inverter)

I suggest verifying that the loads in the panel are balanced and checking the output voltage and frequency of each inverter to ensure that they are the same.