Hi, I recently installed a Multiplus 2 48v 5000VA. When I installed it I updated it to the latest firmware and tested it with a 3000W load and all seemed well. I put it into service but a few hours later it shut down with an over temp alarm. The inverter was pulling a 4000W load at the time and the ambient temp was 26C. I left it for over an hour but the alarm persisted. Any thoughts/suggestions would be appreciated.
Kev.
As can be seen from above, the inverter’s continuous power rating at 25C is only 4000W.
If your load has a power factor less than 0.8, and if there are any air restrictions it will overheat at that level.
You should think about adding a second inverter in parallel, or upgrading to a 10kW inverter if your load is that high.
The 4000W was for only a couple of minutes and I would have thought after a hour to cool down, it would start up again but it doesn’t.
Even 4000W for a few minutes can cause problems if the PF is bad. Did you check the DC input current? If the overload is extreme it could possibly cause permanent damage, what LED’s is the inverter showing? Are you able to communicate with it using a Mk3 interface?
The load was an electric water heater and an air fryer so I don’t think PF is an issue. I can still communicate with the unit using an MK interface dongle and I was not there when the problem occurred so I don’t know what the dc current was. If it was a normal over temp event, it would have recovered but several hours later the problem persists.
I spoke to the supplier who sent me a new PCB for the inverter. Having installed it and updated the f/w, the MP is back in service.