"Witchy" wrote in message
...
Hi folks,

Not been here for ages 'cos of a new job Down South, hence no diy
apart from weekends!

Anyhoo, got an oddity at a mate's house with the bathroom light. The
switch is outside the door and contains 3 cables, one of which looks
like it contains 2 red wires?! 2 blacks are joined in a choc-block,
one red doesn't go anywhere and the other 3 reds are in the switch.

Ceiling rose has 3 sets of cables, one of which goes to another light
which is being removed.

Now the conundrum - with the light OFF there's 240V across the swtich.
Turn the light ON and the voltage vanishes.

Any clues?

cheers

adrian/witchy, now in cambridgeshire.
--
cheers,

witchy/binarydinosaurs

This is completely normal, when the switch is off, one side is live and the
other earths through the bulb, when the switch is on the switch has less
resistance than the meter so the meter shows nothing all the current goes
through the switch. To prove this remove the bulb, the readings should
remain the same, also if you go one side of meter to earth, the other to the
switch you should see 240 on one side with switch off and both sides with
switch on.

mrcheerful