FLEXmax 500 power up issue

[JEMorgan]

Hello all. I recently purchased a house with an older FLEXmax 500 system and I have been having many issues with it, so I have decided to come to this group for help. My system has 10 solar panels feeding 4 12v batteries through two FLEXmax 80's. Power is inverted through two GVFX 3648. I also have grid power running to the system and the whole thing controlled by a Mate 2. They system is used to augment grid power and act as a backup for when power goes out. I recently had to replace the control board on one of my GVFX. I don't believe this is related, the system has worked about a month since them, but mention it just in case.

The current issue: I had to cut power to the house to replace a breaker in my main panel. When I turned power back on, the entire FLEX ware system started flickering on and off as if it was continully recycling power. Everything with a screen flashes on and off. Initially, I thought maybe the batteries did not have the requirede 10.5 volts, so I disconnected them and individually charged tehm to full power using a 3rd party battery charger. Once they all had a full charge, I hooked the system back up and had the same problem. I have checked all connections and breakers and see nothing out of place. I have searched this forum and the web and couldn't find anything related and am on day 5 of troubleshooting with no progress. Any suggestions?

[raysun]

This post must have been held up in the forum machinery.
Did the issue get resolved?

[JEMorgan]

No, I have no clue where to go from here.

[raysun]

The battery is still a good place to start.
What is the brand/model of the battery blocks?
How old are they?

When the system is powered up what happens to the battery voltage while the equipment is cycling on and off?
Can a voltage measurement be taken at the "load" side of the battery main circuit breaker during the cycling event?

[fcwlp]

As your issue happened after doing something in the main breaker box, I would also check the following, with AC input breaker at the FLEXmax 500 off, at main breaker box:
1) Measure voltage L1 to L2 (assumption is you have 240V split phase on breaker going to FLEXmax500.
2) Measure L1 to N and L2 to N.
3) Verify N and G are only bonded (connected) at one location. This is normally in the SES (Service Entrance Section) or first box that comes after the meter.
4) Turn AC input breaker on at FLEXmax500 and repeat steps 1-3.
5) (Edit) Additional steps, measure voltages from steps 1-3 at the inverter with the invert off and inverter on. I once had a bad wire nut on a neutral going to the inverter, resulting in a floating neutral.