Our 150/60 mppt controller is triggering the error code #28 'Power stage issue' when the PV load approaches about 350W. I'm confident the controller is sized properly for the system, which contains seven, 100W SunPower Flexible panels wired in parallel in a 12V system, the panels have the following specs: Voc = 21.4V, Isc = 6.3A, Vmpp = 17.1V, Impp = 5.9A. I enjoyed using the nice new MPPT sizing calculator on the Victron site, thanks to whomever helped build that; the excel file is nice too.
Our controller operates fine at solar yield wattages below 375W but, we have yet to surpass 375W realm without tripping error #28, "Power stage issue". I've found little helpful information in the documentation and other online sources, including this repository. The documentation does state that the controller may be faulty. We have been able to clear the error by disconnecting the controller from both the battery and solar load. After that the controller does operate apparently normally until the solar load again approaches 375W, at which time, the controller will again trip error #28.
I'd like to better understand possible root causes to troubleshoot.
Our overall system, includes a Victron 3000W MultiPlus, a BMV-712 battery monitor, a Color control GX, and 300Ah of LiFePO4 batteries from BattleBorn.
If anyone has knowledge and experience with error 28 in an MPPT controller and can share with me possible root causes, I'd be grateful.