Power assist fine tuning

Q&A and troubleshooting
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1

PowerAssist keeps disconnecting grid under heavy loads , need advice

Hey everyone, I finally figured out a way to keep my grid live without constant relay clicking. I can control everything via VRM, choosing on, inverter only, charger only, and so on. I also set up PowerAssist, but I’m still seeing the grid constantly flicking in and out when running small <300 watt loads and large >q500 watts. like our pump, even though I’m using no grid code, the widest allowed voltage settings, and wide voltage and frequency acceptance. The reason I want PowerAssist is that our grid is very poor, and I want to be able to smoothly run heavy loads using both the grid and inverter together. Are there any settings or adjustments I might be missing to get it working reliably without these on/off cycles?

2

System consists of two Victron MultiPlus 12/2000/80-50 inverters wired in split-phase configuration. Battery is a Vatrer 12.8V 460Ah LiFePO4 with internal BMS. Solar production comes through your PV system feeding the Victron setup through your existing charge controllers (details not specified). System is managed by a Cerbo GX with a SmartShunt for SOC and a VRM connection for monitoring. House loads are fed through the Victron AC output. Grid connection enters through a dedicated breaker and feeds AC-in of both inverters. Grid can supply roughly 3200W steady. Pump is a 1.5HP Franklin submersible with a control box. Pump selection originally used a Pentek U27-1865 mechanical three-way switch. System wiring includes a neutral/ground bonded bar in the main house panel. Your inverter settings use wide AC input voltage and frequency acceptance, grid current limit at 50A, and (currently) PowerAssist disabled. System can operate in inverter-only, charger-only, or inverter-charger mode depending on your VRM selection.

3

It’s not the PowerAssist disconnecting the grid.

Do you have the grid or a generator?
Try to adjust the settings mentioned here:

My guess is that you have a weak AC input and the voltage/frequency is changing too much under load.

4

I have central american grid, not so great. I measured 107v coming in the other day at very low usage hour.

is it a good idea to disable LOM in my case? And/or change boost factor to 1.5? I have a wide frequency range accepted and a wide voltage range.

5

I’ve since tried all these suggestions and it almost made it worse. I’ve played around with lowering charge current limit and grid current limit. Is there anything else I’m missing? Or it’s just too unstable for the two multiplus to help smoothly?

6

I would make power assist 2.0, wide frequency accept, UPS off, reduce AC current limit input to 29 Amps.