I have a MultiPlus-II 48/5000/70-50 combined with a 16 kWh battery with a Seplos BMS. I also have 16 solar panels, connected via two inverters that feed AC into the Victron/grid. The whole house (except for the NS Victron car charger) runs through the Victron system, everything single-phase.
This setup has been running perfectly for almost 2 years and I’m very satisfied with it. However, sometimes something goes wrong and I don’t know why or what causes it. It has now happened twice that the Victron shuts down and my house loses power. The first time was about a year ago, and the most recent time was last Sunday at 15:00.
After the shutdown, the Victron display shows “AC disconnected”. The battery was still online and no circuit breakers had tripped or anything like that.
The difficult part is that I can’t easily bring the system back online because my routers are also without power. What I do now is switch off the power to the Victron and turn it back on again. Then the display shows “OFF”, and the only way I can get the system running again is by connecting my laptop via USB to the Multiplus and manually set the Victron back to ON.
I’m not sure if I can find the root cause, but is there a setting where I can configure the Victron to automatically restart after a shutdown? I will be on vacation next week, and I don’t like the idea that the system might shut down while I’m away.
Hello Fredd, thx for your reply.
Yes it’s a gx device, connecting via wifi is an option for restart. But that doesn’t solve my question ‘how to restart it when i am on holiday’, wifi is not going to help in that situation.
To be honest, I wasn’t aware of the 1.0 rule. My panels can generate at peak around 6000 W. With the feed-through capacity of 50 A, I didn’t see this as a problem. The excess goes to the grid anyway, or at least that was my logic. Maybe a fault on my side.
My grid is very stable, with never too high voltages at times when panels produce a lot in the neighbourhood. My connection is 35 A single phase. I set the Victron to 32 A max to protect the main fuse.
I checked the logs; there were no alarms. The values just before it happened were:
Grid: -4370 W
AC consumption L1: 730 W
Battery current: 0 A (was fully charged)
Grid AC input voltage: 235 V
Car was plugged in but fully charged.
The afternoon it happened was sunny but with small clouds, so solar power went on and off during the failure. Maybe this had something to do with it.
The 1.0 rule only applies when your off grid or when grid is lost, in normal operation it would not matter but you will have to stay under the current capacity of the transfer relay
You could connect one of the pv inverters to ac out 2, this output switches off when grid is lost
Then pv power on ac out 1 will always be at the 1.0 rule
Ok, now it’s a bit confusing. You’re saying it doesn’t matter (when grid-connected), while two others are saying it does matter when grid-connected.
But if it really doesn’t matter, then it’s still a mystery why the Victron shuts down and gives the message “AC disconnected.”
Wiring one inverter to AC out 2 is a good idea, but it’s not practical in my situation. Both inverters go through one Victron power meter and then to the main switchboard. The whole switchboard is connected with two large cables to and from the Victron in the shed next to my house. I’d need to do some serious rewiring to make that plan work.
If I replace the Multiplus 5000 with an 8000, the problems should be solved, I guess? They’re not that expensive, and it would also allow me to charge my battery faster during low times.
Ok, thanks for your explanation. I’ll think about what the best option is to adjust my system so everything stays within limits, also in off-grid mode.
The solar panels I have now are already split into groups, with the idea that in the future I can connect part of them directly via DC to the Victron. Right now I have:
10 panels facing south with optimizers on a SolarEdge inverter
6 panels facing south in a string to a simple AC inverter (I want to connect these directly via DC to the Victron later)
4 old panels facing east with 2 micro inverters
For now, I could also connect the SolarEdge to the Victron? so it can throttle the SolarEdge in case of a power outage. Otherwise I would need to do some rewiring to make things happen.
Update options I’m considering for the future:
Upgrade to a Multiplus 8000 and keep everything AC,
Keep my current system and expand it with a separate MPPT, and connect the 6 panels to that (or possibly also include the 4 panels). This would be the cheapest upgrade and would also allow me to charge the battery faster,
Switch to a Solar RS. I read that the Solar RS is more modern, efficient and quieter, but then I would also need a different power meter and a Cerbo device.
