A couple of years ago the pressure washer I inherited from my father started to trip the mains.
WTF, I thought, it wasn't that good anyway, so I cut the cable off and chucked it in a box, threw away the washer and bought a new one.
Today I decided I needed a longer extension cable.
I took the socket off another old short one - which proved to have red-black-green colours, just how old is that bit of wire? - and fitted it to the end of the pressure washer cable.
All looked OK, so I plugged it in and turned it on.
click-clonk-clonk and the light went out.
It had tripped the breaker in the house that feeds the garage, the main breaker for the garage, and the breaker for the socket circuit.
I checked. I hadn't messed up. but there was a few hundred k ohms between each of the cores.
I pulled the new socket off, then cut off the plug, and it's just the same.
It looks as though somehow the cable has degraded so the insulation isn't quite as good as it ought to be.
Ah well, back to my bog of odd bits of cable...
Andy