We have had the MPPT RS 450/200 working for about 8 months or so, and sometimes in January 21st the system stopped working with error 33 and 35 (logs showed 4 errors 33, 35, 33, 35 in order). This happened right at the time of a firmware update where I logged to check its work status before sunlight and the update proceeded and the next day we saw PV -- (no voltage) and error 33 35 showing.
We thought that the firmware update may have had some reading issues on the PV side and it may have cut off so it needed a hard reboot. We did also factory reset but still it will not read the PV correctly.
We think the issue could be with PV side controller a faulty MOSFET, bad capacitor (blown), or PV voltage reading probes issues.
We did not test to hook the PV arrays on to the other 2 previous unused trackers.
During this time the system had panels covered in snow so PV voltage would have been very low and temperatures were subzero -10C.
We waited for panels to clear and noticed that PV still was reading nothing (--) and charge status off. Error 33 and 35 was not showing until we rebooted the system with power switch off on, and threw the same error where the reading was climbing rapidly from 200V to 344V and then it would cut out and disconnect the PV with status (--) and error 33 35.
We powered off, removed PV arrays, removed Battery from unit and let the system for 10 min without battery. Then we measured battery V at 54V, PV voltage was 204V on 1 string and 203V the other (only 2 are currently in use).
The battery was connected back again, PV hooked back on, hooked the battery back again, hooked the both string 1 at a time, and voltage on meter was reading 204, while on the victronconnect the reading started to climb rapidly to 266V and then it threw the error 33 35 and it showed PV voltage -- and no charging while the PV array still was reading 204V.
The panel system is rated 220V Voc with 8KW of rated power (4KW each array).
Battery system is 54V with LiFePO4 200Ah (3 units) containing 30KWh capacity).
The batteries are charged by this Victron MPPT, and from Power grid with two AC-DC 3P 9KW Power Rectifiers (3 phase to single 54V DC output) that are set to charge only when batteries are at 54V (voltage is set to 54V from AC). The AC-DC rectifier is highly regulated unit that outputs precise set voltage required in telecommunications and broadcasting transmitters, and this is used to also isolate mains power from broadcast (AC-DC-AC). The second Power rectifier (AC-DC) is used for the Generator so that charging is done when batteries fall bellow 54V from a battery voltage monitor with generator auto start.
The discharge sinusoidal inverters are hooked to the batteries 2 x 6KW and they do not charge, only discharge (DC-AC). The constant load is about 5KW.
There is no smell or visible damage.
We have contacted Victron and the seller but we are not hoping for warranty as the unit was purchased in Canada and shipped in another country where its currently being used in Kosovo at a broadcast tower site. We just want to know what part of the system could be faulty so we can repair it and replace parts and if the PV side is modular or its a single board that may need rectifiers and caps replaced as this is the common failure on MPPT that do not have a robust builtin input PV protection.
We suspect the issue may have been caused by two scenarios:
1. During upgrade of firmware some bad values were on the sensors causing rectifiers to work with bad values for tracking
2. The batteries ran out of power cutting battery DC voltage, and PV destroyed the PV rectifiers of the MPPT RS while AC-DC rectifier could not charge due to power outage.
3. Some transient voltage weakened the rectifiers and capacitors.
