After hours of reading, trying things, and tears of despair, I’m turning to this community.
Something went wrong during the configuration (I suspect a UTP cable with a poor connection), which has resulted in my Phase 1 MultiPlus no longer being able to connect. Literally every light is flashing and, from what I’ve read, something has gone wrong with the firmware. However, since it’s no longer possible to connect to VictronConnect, I can’t upload the new firmware.
What I’ve tried so far;
-The MK3/laptop/USB connection works and communicates perfectly with the Cerbo and the rest of the MultiPlus units.
-I’ve tried various plugs and on/off combinations, connecting directly to both VE ports, via the Cerbo, etc.
-I’ve tried using the batteries, mains power, and even setting the switch to inverter mode, but unfortunately…
Does anyone have any other ideas? I’ve found several similar cases online, where multiple solutions are suggested, but all of these threads go quiet before anyone confirms what actually worked
Already tried that, but VEflash still can’t find the MultiPlus either. It tries to connect and then, after a few seconds, displays “communication error”.
OGPS
(Ed @ Off-Grid Power Systems - offgridps.com)
4
Did you have the Multis connected to DC negative and then DC positive before you connected any communication cables to the Multis? Or, did you connected the Multis together with VE.Bus before connecting them to DC negative? Do you happen to remember the order in which you made those connections?
The Multi units had already been connected to DC earlier. First, they were all updated individually to the same software version as a precaution, and afterwards the DC was disconnected again. When I started configuring them, I connected the VE cables first, connected the laptop to the first unit, and switched the DC back on for all of them.
Normally, it should work with VEflash.
At what point does the error occur?
If it really can’t be resolved using VEflash, you’ll need to contact your dealer.
OGPS
(Ed @ Off-Grid Power Systems - offgridps.com)
7
I wasn’t clear. The DC negative cables to all the inverters should be connected to the DC bus prior to connecting any of the VE.Bus cables between the units. That’s what I’m asking. @M_Lange@nickdb Am I barking up the wrong tree here? I don’t want to confuse the OP if I’m thinking the comm board is blown. Thanks!
I never paid attention to connect DC or VE.Bus first…
I do it how it fits in the workflow.
Normally I install bigger Systems together with a colleague and depending on who is doing what it’s DC first sometimes and sometimes it’s VE.Bus first.
OGPS
(Ed @ Off-Grid Power Systems - offgridps.com)
9
From a 230V Quattro-II manual:
“Always interconnect the negative battery cables before placing the UTP cables.”
This is to prevent a return path from going across VE.Bus cables between units, which can blow up a comms board. The VE.Bus connections are not galvanically isolated so this is a potential failure point if someone energizes an inverter into an inverter group and they aren’t all connected to DC negative before doing so.
So I’m wondering if this is just a bad firmware flash that VE.Flash can solve, or is this a blown comms board? Or even something else.
I think that doesn’t matter as long as the batteries are switched off (there is no fuse inserted).
We always use batteries like Pylontech, Pytes or BYD that have to be switched on and switching on the batteries is one of the last steps of the installation.
I can at least say that I hadn’t paid attention to this here: the DC switches on simultaneously on both (+ and -).
I’ve just tested it again with another multimeter, and this one does connect correctly, so at least I know I’m following the procedure correctly.
OGPS
(Ed @ Off-Grid Power Systems - offgridps.com)
12
There are also these notes in Victron’s Wiring Unlimited:
“The rules and guidelines for battery isolation vary in different countries, but it is recommended that if battery isolation is needed, to only isolate the positive battery cable.”
"It is preferred, though not mandatory, to maintain a continuous negative DC connection in the system and only switch, protect, or fuse the positive DC connection of each inverter/charger. This preference is due to the difficulty in troubleshooting a loose connection in the DC negative path, particularly in systems with multiple units (parallel, split, or three-phase).
However, a continuous negative connection is not required, as some installations necessitate that the DC negative be protected by a fuse or circuit breaker."
But, despite the language, I’ve always thought that all the DC negatives need to be bonded to the negative bus bar before connecting any communication cables. And though I know the rationale and how/when you can work out-of-order, I tell the installers in my shop that all DC cables to each device have to be connected before any device is turned on. You don’t want a high-power device trying to find a negative return path over a tiny wire in a communication cable and through a low-current control circuit.
Anyway, I don’t know that this is the issue here. I just wanted to point it out in case the comms board was fried. Regardless, if you can’t fix it with VE.Flash then it needs to be looked at by your distributor or repair center.
