I've just bought a Multiplus (110V, 12V, 3kW) and hooked it up to AC for the first time a few days ago. The only LED that illuminates is 'overload'. The only thing connected is the AC input.
I've attached to it using a MK3-USB and VEconfigure3, and can't see any explanation of the reason for the LED to be lit. I tried to disable/reenable UPS and other features, did a complete factory reset, and nothing changes at all. My distributor just points me at the manual.
Any ideas?
You don't mention connecting batteries, just AC input?
The MultiPlus is a battery inverter, and designed to be connected to a battery. Attempting to run it without a battery connected is not supported.
My first troubleshooting step would be to disconnect all wires and connections except for the DC batteries. Then check and confirm their voltage and polarity with a multimeter at the terminals.
Then see if the error is cleared.
Spoke too soon. I went out again (about 2h after it started working and also I saw current being delivered to charge the batteries from shore power) and turned on the battery again. Back to the original problem: 'overload'. This is with only the battery connected.
Battery polarity is correct (triple checked) and earlier I had seen the multiplus delivering 80A to the batteries (12V) via the smartshunt I had in line. Battery voltage is around 13.5V iirc.
It sounds like you haven’t finished the installation, programming and commission yet, so please do all those steps first.
Thanks @Guy Stewart (Victron Community Manager)and @tmartin000. I did actually have my lithium batteries attached during one attempt, but was nervous about doing so as I was did not want any charging to occur until I had changed the factory settings to accomodate lithium cells. Perhaps that was over cautious, but I had not seen anything in the documentation indicating that batteries had to be attached.
In which case, what happens if the Multiplus is attached to shore power and the batteries are disconnected using my main disconnect. Should AC2 also fail?
I spent several hours starting/restarting and the 'overload' LED illuminated most times. I gave up in frustration, spoke to my distributor who said he had seen the same problem and that a firmware upgrade might be necessary. I went back to it tonight, with temperatures around the freezing mark (about 10°C lower than the first attempt) and the unit appeared to work flawlessly...
Delighed it is working, but a little confused. This is my first system (van conversion, Smartsolar, MPPT, smart shunt, and multiplus with 480Ah of LFP) and I'm just getting things sorted out.
Which lithium batteries? Some may disconnect themselves at freezing temperatures if there is any inflow current.
Definitely follow the distributors advice and have all firmware up to date.
There is a good chance that if your batteries disconnect themselves during operation that the MultiPlus will shut down as well (on overload, low dc voltage, high dc ripple, or some other error). That will also disconnect AC2out.
I recommend a manual bypass switch from AC input to AC output that cuts the multi and battery system.
