I have been using my Victron system for 3 years now without any problems.
The setup is as follows:
3x MultiPlus II 48/3000 (as a 3-phase system), 2 DIY battery packs (China, EVE), each with around 14 kWh.
The cables from the public mains supply go directly to the MultiPlus units and then back into the distribution board via AC-out1 to supply the house.
I live in a single-family house with one other person.
Since 4 September, the following problem has been occurring: I have occasionally had a brief power cut in the house (around 3–4 minutes according to the records). In VictronOS, I receive the notification shown in the attached scan.
The batteries show no abnormalities (the cells are monitored individually), and there have been no unusual incidents in the house either, nor any unusual fluctuations in the power supply. The strange thing is that nobody was in the house on either of those two days (4 September and today, 8 September).
I was only able to detect the power cut in the house through the VictronOS notification and because the cooker was not showing the current time, but only had a flashing time display.
My questions to you are: Has anyone encountered a problem like this and know or suspect the solution (before I embark on a time-consuming investigation)?
And what does the “#1” before the text mean? Does it mean that device number 1 briefly failed? How and where could I read out any further errors, if necessary?
I can access all the data from VictronOS via MQTT.
You might want to check the “Remote” link on the Multis for loose screws … Recently, this was exactly what caused a Multi to suddenly shut down … the screws had apparently loosened due to the humming of the toroidal core …
I’m only getting back to you now because I wanted to monitor my system until the next fault occurred, and then test it based on your suggestion.
The same fault finally came back the day before yesterday, after several weeks. That makes it the third time now.
Today I checked my three MultiPlus IIs as you suggested.
All the screw connections were tight, as was the Remote jumper.
BUT I noticed something else. I bought my first MP in 2023, and the other two about a year later.
The serial numbers show this: one unit is HQ22, the other two are HQ23. The only hardware difference is that the older unit has a jack socket for connecting an external Current Sensor, while the two newer units have a 3-way connector with a jumper wire.
I looked it up online and found that Victron stopped fitting jack sockets in units from around 2022/2023 onwards because they could develop contact problems over time (the internal spring weakened).
Well, maybe that’s my problem too. Hope dies last.
For now, I’m going to get a 3.5 mm jack plug, short the contacts and plug it in.
And then it’s a case of waiting again.
if you short-circuit it, you’ll have problems too. There’s a changeover switch in the socket, and you can only reach one of the contacts, not both. You can try plugging the connector in and out a few times; usually the contact will then make a good connection again. Otherwise, you’ll have to open it up and clean the contact, replace the socket, or bridge the switching contact. But then you won’t be able to connect an external sensor any more!
#1, normally means “the master”, I presume that’s the one with the jack.
Also check your “bus” wiring, check inside if these sockets do not have a bend pin or corrosion, cat5 does the job, cat6 is slightly better shielded, cat7 is even better shielded, I use server patch cables instead of ethernet cables from the DIY shops, maybe these get old and are these away from the 230V cables?
You also might check the grid voltage (low/high) when it occurred.
Thank you very much for answering my second question.
Yes, the master is the older MP.
I’m using Cat6a cables, and unfortunately some of them run close to the 230V power lines.
I’ll try to separate them a bit over the next few days, although I won’t be able to move them completely apart.
Especially since this whole setup has been working without any problems for over three years.
I’ll check everything again first thing tomorrow and then switch it back on.
that doesn’t necessarily mean anything. When I upgraded from an MP 5000 to 3, it sometimes worked and sometimes it didn’t. Switching on AC-in was always a problem until I configured one of the new ones as the master. Since then, there haven’t been any problems.
So try using one of the new ones as the master; perhaps that will solve your problems.
Indeed, it might help, but, the only thing is the firmware, if these are are all the same, old inverter or not, not any issue, so, that’s not it…
In one of our installs the first inverter is still master, and that’s running now 14 years with one slave of 12 years and a resent one with 6 years…
The same firmware…
Well, lately, for some inverters (mostly the 120V ones), as is written by Victron in another topic, these must have the extended letter (Alphabet) to be able to work together, but that is not the case here.
After trying the suggestions so far (a few days ago) and expanding my Grafana setup to record the current incoming voltage readings for L1, L2 and L3 (I hadn’t previously seen the need to do this), the power in the whole house has just gone out again (from 22:18 to 22:23).
Same fault: device #1 appears to have shut down. After around 4–5 minutes, the devices came back on again without me doing anything.
The only thing I hadn’t done yet was reprogram my devices so that device #1 is no longer the master, but another device is.
So, now I’ve looked at the curves for the 3 phases just before the outage and have to note the following:
The power outage was around 22:18. You need to look at the top 3 zigzag lines.
A few minutes earlier, the highest value for L3 was at least 240 volts. Is that OK? Is that possible? Is that allowed?
I’m just surprised that immediately before the outage, the power on all 3 phases was apparently back to normal.
Over the next few days, I’m going to change the software so that L2 becomes the master.
Then all I can do is wait and see.
Should I perhaps even be worried that there’s something wrong with device #1?
I’ll keep you posted and hope to hear from you.
Good night,
Regards,
Heiko
P.S.: I’ve just checked again. Apparently the shutdown CANNOT be caused by voltage spikes at AC-IN. The specified voltage range is 185–265 volts. If these limits are exceeded, the Multiplus units do NOT shut down, but switch to backup power. That’s exactly what I got them for.
So the shutdown must have some other cause.
Holger has hit the nail on the head. I’d never thought of that, and I should have noticed it myself:
My Raspberry Pi is powered by a DC/DC converter rated at 2 Ah and is connected directly to the batteries.
So Holger is absolutely right. If the MultiPlus units fail, the Raspberry Pi should actually keep running, and at the very least the battery readings should still be displayed.
Man, how stupid of me.
So I assume I’ve found the cause of the intermittent failures.
I’ll replace the DC/DC converter with a 6 Ah model.
I deliberately did NOT power the Raspberry Pi with a regular power supply, because I wanted the battery readings and the controls to keep working if the power supply failed.
Right, I’m heading down to the cellar now to replace the converters.
I’ll report back after a while.
Thanks again to everyone who helped me with tips and advice.
