We have a “modest” ESS setup for our house which is supplying power for a 3-phase system on L1. I have observed that the Multiplus-II 5kVA has a tendency to very quickly derate itself due to temperature but the fan is not active. As you can see from the video below, the temperature of the casing rises to around 35 degrees Celsius (which indicate the electronics/transformer inside might be in the neighborhood of 70 degrees), thus triggering a temperature derating. The problem being that the fan does not run at all. Usually the “Temperature” light on the inverter flashes red but for some reason it is not flashing this time. Must be camera shy like me
I know for a fact that the fan works because if the room temperature is high enough, the fan will be active. But now that winter is slowly settling in, the room temperature has fallen to 19 degrees Celsius and thus the fan no longer seems to be used. At the beginning, the inverter supplies its full allocated power (in this instance 16A so 3.68 kW maximum, usually a bit less of course because reactive power) but then falls to around 2 kW after less than 5 minutes. The fan DOES NOT RUN when it derates
The battery is not causing a current throttling as it is not heating up. We are using 2x Pylontech US3000 in parallel for a total of 74A of available discharge current. Current limit on AC-in is set to 16A. Nothing else in the DC distribution is heating up excessively and could cause a derating (not that the inverter could know anyway). Firmware is up to date. This problem exists since I purchased the inverter. Support says that I should perform firmware updates and resets but are of no further help. Quiet mode Assistant is not loaded. The fan is free from debris (able to spin) and is plugged correctly
Can you share the battery charge/discharge limit charts from advanced section of VRM?
That is way too little battery for that inverter, it will only get you around 3kW output after losses.
(also, what is the actual load?)
Indeed the battery system could use an extra one but there are several reasons why the system is designed with “only” 2 of them We have limited space available, the setup is in our office room inside the house. The AC-in cabling is limited to 2.5mm2 because we cannot fit anything bigger in this very very old, post-WW2 German building. For safety reasons, we limited the AC-in current to 16A (and thus a maximum power of 3.68 kW). This happens to exactly coincide with the maximum power that the battery can deliver, 74A at ~50V (49V would be low SoC and thus inverter stops). Losses are very minimal and usually negligible due to very short and thick cabling. Earlier on, there was much more sunlight and the MPPT was supplying more power, about 1 kW but the inverter was still derated
The load was purely resistive: we are pyrolysing the oven. This is why I made this post, it seemed to be the best case scenario to show what was going on, especially since the oven is on L1 and in our apartment, only the oven is on L1
Hope this helps. Let me know if you have any more question!
If you increase the current limit, as a test, does the balance change at all?
Which grid code are you using?
It may be helpful to post your inverter config and anything you have configured in ESS or DVCC, on the GX.
If anyone encouters the same problem and find this thread: I will eventually post the solution here and pin it
Although so far I have been trying for weeks to get in touch with my provider’s customer service in vain, as they are not responding. As far as I know, there is no direct channel through Victron to directly get support from them (outside of forums of course) so I will continue trying with my provider until something works (maybe showing up in their office might work )
Try logging a request through the victron support link which is in our guidelines, it gets routed to the supplier but it provides some visibility.
Also, you can afterwards contact the regional sales manager, details on the main site contacts list.
I went through Victron support page to send the original RMA request. I got no response and when I got the automatic message for feedback from Victron, I left a negative one and magically got a reply from the supplier saying that this was the wrong point of contact
They gave me a new one which was a dead end, as the “Send” button did nothing. This is most probably on purpose for warranty to expire before you can do anything I suppose
It would help if you used the relay assistant, fan option which closes the really when the fan runs. If the relay is operating then there is something wrong with the fan this should be a a good test to see if it should be running or not.
We have limited space available, the setup is in our office room inside the house. The AC-in cabling is limited to 2.5mm2 because we cannot fit anything bigger in this very very old, post-WW2 German building. For safety reasons, we limited the AC-in current to 16A (and thus a maximum power of 3.68 kW). This happens to exactly coincide with the maximum power that the battery can deliver, 74A at ~50V (49V would be low SoC and thus inverter stops). Losses are very minimal and usually negligible due to very short and thick cabling. Earlier on, there was much more sunlight and the MPPT was supplying more power, about 1 kW but the inverter was still derated
