I have a 12/500 Phoenix inverter. I run a small AC compressor fridge from it. It's nominally 70W, but I see around 660W when it initially turns on. Although 500VA continuous, it's 1000VA peak, and equates to 700W peak by my reckoning (not sure how they work that out). It would always start first time, although I would get that momentary hum when first starting. But after only a few weeks reliable running, I now get a permanent "overload" fault, even with no load connected.
I was told that the overload protection diodes may have failed through stress (a fail safe state). Does that seem fair?
For a time I was running the system from an old battery, and I can well imagine the voltage was very low at times (may have got a low voltage cut out fault on occasions). Would running the (momentarily) high load mean at low input voltage more current flowed, causing accelerated stress?
I'm now running from a Lithium pack which will be well charged at all times, and more than capable of supplying the power needed. But I'm worried that even if I have the inverter repaired, the same thing will happen again - repeated overload, even if momentary, will stress the inverter to failure.