I found these while researching a non-functioning bathroom exhaust fan
in my partner's flat (apartment) here in the UK.
This fan was within the shower enclosure, 1 foot (30cm) above the
shower head, certainly within the spray zone.
The initial symptom was that the fan would run only intermittently,
and not at all on it's automatic (humidity controlled) setting.
The fan was connected between blue and yellow, with the red capped.
From the fan isolator switch location, I could tell the red is
supposed to be permanently live, blue neutral, and yellow switched
(with the bathroom light). However in this isolator switch box, the
yellow was capped off!
All became clear once I had removed the fan. The fixing screw had
penetrated the cable on its way into the red plastic wallplug, and
shorted red and yellow. It had stopped working because the damp had
finally rusted away enough of the galvanized screw to break the
connection. (Apart from the fizzing and arcing).
This was obviously faulty from install, yet the installer covered it
up (or didn't realize it was a fault, not sure which is scarier).
What terrifies me is that this fixing screw was in a brick wall less
than 1 foot (30cm) from the fixing for the metal shower enclosure.
Anyone want to risk the damp plaster not being conductive enough to
cause dangerous leakage to the unearthed enclosure frame?
Happy ending however, I was able to pull out enough slack on the cable
to get a new termination neatly (While avoiding the cable with the