my customer is living in a far away area and he has no internet connection. Just one Multiplus II 48/5000 would be fine for his needs, however he would like to be on the safe side, so that I am wondering if I can propose him a second Multiplus 48/5000.
I would then program the two Multi’s parallel.
Here is the question : What happens if one of the inverters fail ? Could the second inverter immediately take over the loads and continue or does it also stop working ? So that I need to go on site and re-configure as one Multi ?
By the way many cheap chinese off-grid inverters simply to that. If one fails, the other inverter assings himself as the master and keeps working.
it would be great if there is a possibility for Victron products as well.
Up to six identical units, with the exception of the 8k, 10k or 15k units*, can be connected in parallel. When connecting inverter/charger units in parallel, the following requirements must be met:
All units must be connected to the same battery.
A maximum of six units can be connected in parallel.
Only identical devices may be connected in parallel.
The DC connection cables to the devices must be of equal length and cross-section.
If a positive and a negative DC distribution point is used, the cross-section of the connection between the batteries and the DC distribution point must at least equal the sum of the required cross-sections of the connections between the distribution point and the inverter/charger units.
Place the inverter/charger units close to each other, but allow at least 10cm for ventilation purposes under, above and beside the units.
UTP cables must be connected directly from one unit to another (and to the remote panel). Connection or splitter boxes are not permitted.
Always interconnect the negative battery cables before placing the UTP cables.
Only one remote control means (panel or switch) can be connected to the system.
Thanks, I have also read that, but it is not clear from that, what happens in case one of the parallel devices fails. Obviously the system will pop up a notification at the cerbo or color control, however will it stop totally or continue working ?
I think I have found the answer to my own questions : in the manual in section 6.3.2 it sais for the ve.bus error code 17 : ‘One of the devices has assumed ‘master’ status because the original master failed.’
In this case the system continues to work, which is really good news !
my setup will hopefully be online in a couple of months and I’ll have 2 multiplus II 48/5000 and can try and see what they do when I cut one off. not a very good test but its the best I can do…
I will setup the same devices next week, I will write my experience then. I am positive but might be that I misunderstood the manual, as a ve.bus error usually stops the AC output…
Parallel inverters are one system. If any unit fails the whole system shuts down. It is not a configuration for redundancy, you would have to reprogram the remaining unit as standalone, and isolate the faulty unit from the rest of the installation.
All done manually.
thanks for the message. But this is not totally true. Please check manual of RS Smart inverter of Victron. On section 3.10 it clearly addresses this issue. (‘2. Increased redundancy, allowing for continuous uninterrupted operation when a single unit (or more) is offline.’)
it seems that the new RS inverters can work redundantly, the question is , what about the Multiplus II devices ?
My answer was about the Multiplus’s/Quattros. It is as stated. They are different architectures and I have been through this process myself.
The RS inverter/charger doesn’t even support parallel (yet), only the RS smart inverter.
@bulent.aydin Hello, This is an interesting thread. Redundancy sometimes is best served with the simplest solution being the best. If redundancy means we want the system to be backed up in case of any form of failure the redundant system needs to be isolated from the main system.
By paralleling them we are assuming something about the expected failure mode of the main unit.
For true redundancy you may consider having two units isolated with the second unit activated by simple switching of input and output mains. Maybe separate Battery feeds may not be required if you think that is going too far.
The client could be told that in the event of failure, switch these contactors and the other inverter charger will be brought on line. I admit it is not as elegant as a software controlled soluton where it all happens in a couple of milliseconds and the client is not disturbed but for high level robustness, sometimes simpler is better.
: in the manual in section 6.3.2 it sais for the ve.bus error code 17 : ‘One of the devices has assumed ‘master’ status because the original master failed.’