[Opinion] Load shedding detrimental to electronics

[Alfred M]

Mov on smps pc board after load shedding yesterday tripping rcd

[Justloadit]

There no fuse on the board.
Had it a fuse, then it would have survived.
In all probability, the PSU may be OK.
You need to remove the MOV, clean the board with PCB cleaner, and ensure that there is no black soot any where with a stiff brush.

Then spray the board with conformal coating to protect the board, replace the MOV with a 275V, and judging from the foto, looks like a 7.5mm. The best would be to cover the MOV with some heatshrink tubing to prevent the soot spraying all over when it fails.
Use an inline fuse holder with a 1Amp fuse to the PSU circuit to reduce the failure.

[Alfred M]

Op amp opto coupler and pwm damaged will fit a tvs diode and incorporate a 2amp fast blow fuse to live coming in to the supply

[Alfred M]

On second thought cant use a fuse with tvs i will clean it all up and put a mov back with fuse protection