Dear all, we would appreciate some assistance, ideas and solutions.
Problem:
We had the 3rd Quattro (in 9 months) where the Transfer Switch has burnt out. This was 4 weeks ago. During Covid time (no Activity on the Lodge). Constant Load at 4-6 kVA.
The phases are fairly balanced with a max diff of 38%.
The other 2 Burnt out during operational time (load of 30-41 kVA).
6 x 10 kva Quattro in 3 phase config(2 per phase). with 613.8 kWh LiFePo4 batteries. The batteries, PV chargers and Quattros meet on the main Bus bar. All Cables where made the same length DC as AC. For the Ac input cables and Output cables we have used 10mm^2 single core cables (L & N).
We have installed many of the 3 phase Victron systems over the years. Currently we are experiencing problems with one of them (offgrid).
We are busy doing a power analysis with a PEL Logger - just to ensure on the output/ Load side all shall be fine.
The Transfer Switch only burns out when generator is in use. The Generator is a cummins (On the enclosure, don't know which specific "generator cummins used) with 95 KVA prime power.
The Settings have been checked several times and do agree with our std settings for all our system.
What we have noticed is that on the input as well as on the output side the system does not shut down when a single inverter trips on the breaker. We have double pole breakers for each inverter on the input and output. Once you trip (manual) inverter 1 input whilst generator is running, the system does not shut down. The complete load which was divided between L1 master and slave now runn's through L1 slave.
why is that? The system should recognise the major difference in A running through one inverter and then shut down? On the other hand, the breaker of inverter 1 should trip?? ensuring that the TFS does not burn.
We have now decided to temporarily change the AC Input and Output all to one combined breaker just to protect the system??
Maybe its a problem which could have been caused by the first installer (non experienced guy and system was not working thus the owner called us. We ripped all apart and re did the installation to our satisfaction using the 3 months old equipment).
Otherwise the system is working superb, except for once in a while, without waring one inverters transferswitch burns.
