[RE-wrenches] XW Pro Firmware 2.04 melting devices

[Kevin Pegg]

Hi Wrenches,

Curious if anyone else has seen this issue.

New XW Pro off-grid system installed Dec 2023. Pretty standard config for us, XW Pro, 5 kW PV, 50 kWh UnigyII battery, 8 kW high quality diesel generator. This system ran fine all winter long - powering customer's big RV they were living in while the house is built, Shop, computer controlled outdoor wood boiler, domestic loads + 3 person construction crew. Gen ran daily on auto start as we don't get much sun Dec - Feb. No issues reported.

Couple weeks back I did a new system check up. All performing well, happy client. Part of that service I upgraded the XW firmware from 1.09 to 2.04, and insight from 1.16 to 1.18. Gave the system a quick check, ran gen. Lots of sun now, batteries full so didn't do a long generator test. Yes I set the region codes for off-grid.

A week later, while I was out of town and it was not so sunny so gen running, client and their electrician called me in a panic. Two smoke detectors had literally melted, as well as several dimmable LED fixtures all failed. Electrician replaced the burned up devices, only to have the same thing repeat a few days later. Talking with them it was only when the generator was running there were issues. Told them to lock out gen and I will get there when I can.

Once back I attended site, fired up gen, and could hear the inverter sounding terrible during gen charging. Lights flickering bad, and I personally verified the smoke detectors beeping and getting warm and the house smelled like burned plastic. I hooked up my power quality analyser and could see the THD gradually building to over 36%. Gen voltage was at 125/250V a bit high, so adjusted that, but no change. By reducing the charge rate on the XW Pro to 50% was able to get the THD down around 12% and less light flicker. But it's still too high. Image attached shows THD with gen on original programing, then at reduced charge rate.

Have now gone from a happy client to a pissed off client threatening legal action for endangering their lives & a bill from the electrician. Ugh. Having a hard time explaining this to the client why a system previously working fine went sideways so badly. Old guy blames the "darned computer stuff" and he's not wrong with that opinion.

At another site, similar config but larger system with dual XW's that I upgraded to 2.04 firmware remotely few days ago and now the two inverters are literally fighting each other under generator charge - one load building to +6 kW and one (minus)6 kW.

Sure makes me reluctant to upgrade firmware on systems that are working fine.

Any suggestions?

Kevin







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