PierreJ Posted January 6, 2021 Posted January 6, 2021 Hi, I have a Multiplus II 5kVA unit (hardware revision 5, configured as part of an ESS system) that is reporting temperature warnings from time to time. Below is the screenshot of the VE.Bus Warnings and Alarms for the past 30 days: The highest ambient has ever been is 34C, but it hovers around 30C on most days. Airflow around the Multi is not obstructed: The warnings coincide with heavy loads either at the input or output side, and it running at capacity. I find that it derates to 3700W very soon after a heavy load (e.g. geyser) is switched on. I've never seen it derate lower than 3700W though. The fan turns on whenever the load exceeds about 1kW, which is most of the time. When the fan is blowing I can feel a slight draft at the intake vents at the bottom but the airflow at the top exhaust is barely perceptible. The top exhaust grille also feels very hot to the touch under load - almost too hot to touch, so I guess close to 60C. Something else that bothers me is the barrage of overload warnings being logged. The grid is (almost) always available, so there should be no reason for it to go into overload. Is what I'm seeing normal, or is something amiss? Thanks! P.S. Ignore the low battery and DC ripple warnings - the batteries were temporarily disconnected during a firmware update to revision 478 (the latest). Quote
Buyeye Posted January 6, 2021 Posted January 6, 2021 Hi this sounds serious. I have a different brand 5kw inverter and it reports overload when loads are 5400 watts and over. The excess load seems to be producing the heat. My suggestion would be to either remove the geyser or get a lower power element. It sounds urgent. Quote
NigelL Posted January 7, 2021 Posted January 7, 2021 Hi Pierre See the following thread - it is possible that you may have a similar issue (?). https://powerforum.co.za/topic/4347-victron-behaviour/?do=findComment&comment=63697 Quote
NigelL Posted January 7, 2021 Posted January 7, 2021 12 hours ago, PierreJ said: Something else that bothers me is the barrage of overload warnings being logged. The grid is (almost) always available, so there should be no reason for it to go into overload. The "overload" warnings only mean that the AC loads are larger than the Inverter maximum power output. In this case the power difference is sourced from the Mains input. As far as I know, this is quite normal in an ESS setup and is purely "informative". The temperature warnings are not normal and should be investigated. PierreJ 1 Quote
PierreJ Posted January 7, 2021 Author Posted January 7, 2021 Hi Nigel, 20 minutes ago, NigelL said: See the following thread - it is possible that you may have a similar issue (?). https://powerforum.co.za/topic/4347-victron-behaviour/?do=findComment&comment=63697 No, fortunately my situation is not that bad. I have a later hardware revision (v5), so it should not be affected by that particular issue. My Multi regularly throttles down to 3700W, but I've never seen it go lower. I wouldn't have taken much note of that if it wasn't for the temperature warnings. I've now set the "Limit Inverter Power" ESS setting to 4kW which will hopefully stop the overload warnings. Apparently the efficiency drops quite a lot under heavy load, so perhaps limiting it to 4kW will also lower the temperatures (I noticed that it will occasionally output 4.4kW for short periods of time). Quote
NigelL Posted January 7, 2021 Posted January 7, 2021 (edited) I wonder if the fan is installed correctly and not possibly reversed? It is quite easy to remove the front cover to check this. Edited January 7, 2021 by NigelL Quote
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