I replaced the thermal fuse in my air fryer. Plugged it in and switched it on (outside) and it worked...
... for 10 minutes. Fan motor ran, heating element was on, temperature setting was adjustable so I left it for a few minutes longer. When I came back not only had it blown its own 7A fuse but it had tripped the garage circuit breaker and also the house circuit breaker that feeds the garage. Impressive.
Obviously a short. I've measured between live/neutral and earth and it was ok so maybe it needs heat.
I've dismantled it again and cannot see anything obviously wrong. The only thing I can think of is connected with the bulb temperature sensor - I had stripped the heat resistant tape from most of it and put it back without the tape and the (naked) wire feed back to the temperature control was effectively earth maybe it moved as it heated up and shorted.
(sensor looks like this:
https://www.jaye-heater.com/temperat...capillary.html)
There was no exposed live wiring and I couldn't find any breaks in any of the wires. I did see what looks like a scorch mark on the motor's rotor but I think that was from manufacturing and no wires were near the motor anyway. The new thermal fuse hadn't blown though, so there is that
I've ordered some 7A fuses and some heat resistant tape and I'll try again.