Zwy
Solar Wizard
I used a scope on mine when the lights would flicker. Waveform perfect really, frequency held steady. Voltage would fluctuate between 112V and 126V. I wouldn't purchase a scope for just this purpose, borrow maybe but really all it will show is the voltage regulation problem.I've checked the AC Inputs and Outputs with a multimeter and it all looks pretty normal (I think) Running 122v steady AC IN and 119 AC OUT. AC IN shows about 0.3v N to G. AC OUT is about 2.2V N to G. I don't currently have access to a scope but could borrow one. How would I test with that and what would I look for?
Went thru the whole process of checking circuits and even running some new ones. Flicker remained, actually seemed to get worse.
Sig Solar sent me the needed USB to serial cable free of charge after sending Ben a DM. I finally updated the firmware last night to the latest mobile firmware and the flicker has been absent. I used the mobile firmware update because I do have the bonding screw in one inverter.
You state the firmware is latest, I'd make certain it is by comparing the inverter display to the current download for the firmware. Adam put this in resources also. https://diysolarforum.com/resources/eg4-6500-firmware-changelog.319/
As for the lights being on when turned off, there most likely is a problem with your neutral/ground. Power is not coming thru the switch, the only path would be neutral to ground. Three things to measure with your multimeter. L to N, L to G and N to G. The L to N voltage added to N to G voltage should equal L to G voltage. If not, you have a problem. I do see you have a ground loop between inverters. You should only have one EGC run to each inverter or daisy chain them back to the main panel. I purposely kept the EGC from PV from my AC ground busbars and ran it back to the main or subpanel busbar which is close to the ground electrode.
This is how I wired mine, note the EGC runs right back to the main panel. https://diysolarforum.com/threads/neutral-ground-bonding.61081/post-760902