[Station X]

I had a washing machine which would routinely trip the RCD during the spin cycle. Megger tests showed everything was OK.

Eventually I took the panels off and inspected the wiring. This was secured using bin bag ties with a steel wire insert rather than plastic cable ties. The steel wire of the tie had cut through the plastic insulation of a wire serving, I think, a temperature or level sensor attached to the drum. During the high speed spin cycle, movement of the drum was stretching or flexing the wiring and earthing the chafed wire to the chassis and tripping the RCD.

A bit of plastic tape over the chafe and fitting proper cable ties gave the machine many more years of life. Eventually the telescopic shock absorber ripped its mounting off the drum holing it, rendering the machine BER.