Hi!
I am having some issues with a Quattro 48/10000/140-2x100 that i installed about a week ago. It is an older used unit with firmware 143.
It seems to be tripping the output breaker in the fuse cabinet when i turn the unit off for some strange reason.
The general overview of the system is:
- Offgrid system, large cabin high on the mountain
- 30 kVA diesel genset 230 V delta connected, cabin is wired with IT ground (no ground)
- Output of generator goes to water heater (L1-L2), industrial dishwasher (L1-L3) and the input of the Quattro (L2-L3). Each of these is fused with 16 A, 25 A and 32 A fuses respectively.
- The other loads in the system is on a separate busbar with a MTS (manual transfer switch). This MTS is basically two interlocked MCBs each with a 63 A fuse. The input of the MTS goes to the output of the quattro and to the generator. This lets me supply the loads directly of the generator if the Quattro is malfunctioning.
- The loads are fused with either 10 A or 16 A fuses. The loads are things like water heater, freezers, fridges, various electronic equipment and lights.
- The battery solution is a 280 Ah, 16S LiFePo4 pack with a 200 A (350 A for short periods) BMS.
- System is configured to turn on generator when the load exceeds 5 kW for 10 seconds.
- I also have an override that always keep the generator on if necessary (for example when using the dishwasher)
- The system is turned completely off each night
Yesterday when the Quattro was set in the off position, the 63 A MTS breaker on the output of the Quattro tripped. At this time the generator was still running (this was turned off 5 seconds later) and when the Quattro was turned off the battery was in a float state, charged to 100 %.
Does anyone have any idea what could have caused this ? I have had it happen once before, but that was when the Quattro turned itself off due to low DC/high ripple likely caused by a BMS disconnect. The cell protection on the BMS is perhaps set a bit too low (3.55 or 3.6 V I believe) , so 100 % charge (56.2 V) is a bit close to cell overvoltage.
I am no longer on site unfortunately and therefore do not have access to the system, but I do have a GX device setup and VRM. Unfortunately it is powered from the quattro output so i do not have much in the way of logs.
