Isolation switch

timestar

The pull cord isolation switch for my shower has developed a fault, i.e. it no longer cuts the power. As my local DIY shop stocks replacements, is this a job for the home person, or do I/should I get an electrician in? Thanks!

liitleblackcat

I changed a 45amp double pole switch for our electric shower about 3 years ago. Apart from the difficulties with the size of the copper cable (very hard to bend), it was quite easy to do a like for like swap.

happyhero

Hi It is as liitleblakcat says (I am a retired electrician) very easy but very stiff cables. What you hope for is a switch with the same layout inside so that you do not have to bend the cables to new locations, so same make is preferrable for ease.

What to watch for:-

obviously make sure that you are sure which circuit breaker will kill the power to this circuit

also when buying this switch remember this is not an ordinary pull cord switch it is a heavy duty one and will be more expensive, you need to insure it is a 45A or 50A one. You can get them most places that you get an ordinary light switch pull cord.

Any other questions about this just ask and I will answer.

timestar

Thanks for the replies - as with most electrical things like this it is getting the wiring right that is my main concern. I have Googled for pictures etc. bot not found much of use.

liitleblackcat

It's very obvious where the cables go inside the fitting. There are three cable connectors for the incoming cable from the consumer unit with big screws, labelled N for Neutral, L for Live and E for Earth and three for the outgoing cable to the shower unit. Make sure the red or brown wires go in the L connectors, the black or blue wires go in the N connectors and the yellow and green wires go in the E connector.

The only thing you can get wrong is to connect the input wires to the output side of the switch and vice versa, but even that doesn't really matter with a double pole switch (other than the little neon lamp not lighting up when the switch is on). If that happens, take the switch off and turn it round.

As happyhero says, you need to be sure that the power is isolated before doing anything like this as the current will kill you and not just give you a nasty shock.

Go for it - it's really quite simple. Switches cost about £15 but less on t'internet - search for "45 amp double pole ceiling switch" on google. And remember you need to make sure the switch matches the current your shower uses and the cabling going to it. A 9kW shower needs 45 amps switch and cable and a 10kW needs 50 amps.