Shower Ceiling Pull Switch

[diynewbie]

I had an electric shower fitted about 12 months ago. This morning the ceiling pull switch failed to illuminate and the shower was dead to the world. Strangely the 40A MCB was still in the ON position (expecting it to have tripped to OFF).

Upon my return from work I removed the 45A pull switch (after switching off the MCB!) to find that the LIVE OUT wire was melted and discoloured. I removed the switch and tested with an AVO for continuity when in the ON position. no continuity across LIVE IN/OUT.

OK so I need a new pull switch but what bothers me is why did it happen and how can I stop it happening again Could loose wires have caused this; why did the MCB not trip? We do not have an RCD in line just a separate trip covering the whole house.

Thanks in advance for any suggestions.

 

[breezer]

your mcb would only trip if you had a short circuit (which you didn't)

it could have melted for two possible reasons

1) the switch can not carry that amount of current (its too small)

2) The live out wire was loose, and so caused arcing and burnt the switch out

I would favour 2