Hello,
I have a 3ph system with Multiplus 2 (one 15kva in every phase).
When first commisioned the system (4 days ago), and with only batteries (49Vdc) connected to the converters, (ac brakers in open circuit), when turned on, one of them didn’t start in inverter mode, but for a few minutes a sound like a trasfer relay came every 20-30 seconds. I tried to cennect to it with ve bus to usb to update it and parametrize for 3ph system but I understood that the multiplus was restarting or something because when software tried to read values the relay sound came and it stopped reading and then had to search for the inverter again.
After a few minutes in this situation a bad noise came from the inside of the inverter like a capacitor was blown and after that multiplus turned automatically in inverter mode and I was able to connect and parametrize the inverter like everything is normal. No bad smell, no smoke came out of the unit.
I called distributor because I didn’t feel safe to connect the inverter but I did not get any answer.
I updeted all inverters and parametrize 3ph system and left the inverters only with batteries connected for two days with no alarm.
Yesterday since still I did not receive any answers from the distributor and since I openned the multiplus cover and everything seemed to be ok, I connected AC in and AC out to supply energy to the loads.
I set virtual switch criteria to the inverters and play with power limits in order to ignore ac in, so i could check that the system was properly connecting and disconnecting to ac in.
One of the times that ac in was about to be connected to the multiplus due load criteria, I received in the gx device a 3ph rotation warning while system was trying to connect to ac input (Grid).
Connections and rotation were correct, and after this multiplus with a second attempt accieved grid connection and charged the batteries and supplied loads from AC in.
Since I never had this face rotation alarm before in other 3ph installations, I am thinking that it might had to do with the noise that one multiplus did when first comissioned.
Can someone help in what tests should be done in order to check if everything is ok?
The rest of the times ac in connects and disconnects fine.
Thank you in advance.