Power cutting off when trying to fit shower switch

Discussion in 'Electricians' Talk' started by craig mcc, Jul 11, 2014.

  1. craig mcc

    craig mcc New Member

    I had to DSC_0018.JPG DSC_0018.JPG
    I cut back the wires and removed the damaged wires but when I try to reconnect to the switch the power in the flat cuts out. Obviously its switched off at the box but I have the power on for the rest of the flat. Do I switch off the power completely to reconnect the switch or is there a fault somewhere else. Thanks
     
  2. FatHands

    FatHands Well-Known Member

    That live wire has got hot at some stage - not just the end part of it but the insulation further up looks out of shape when compared to the wire on the left.

    Has the switch been opened up because a protective device is disconnecting the supply to the shower?
     
    Last edited: Jul 11, 2014
  3. I'm guessing you are tripping the RCD which is usually part of the 'big' main switch in your consumer unit. (It'll have a 'test' button on it.)

    Even tho' you've switched off the specific MCB for the shower, this only isolates the 'live' (red) cable and the 'neutral' is still connected. I understand that if even the neutral touches the earth it can trigger the RCD to trip.

    At what stage of your rewiring does the RCD trip - which wires have already been fitted and which one are you fitting when it goes 'clunk'?

    What caused the wire to overheat? Are you sure that the switch itself is fine?

    Anyways, proper sparkies along soon... :)
     
  4. craig mcc

    craig mcc New Member

    The wire has got hot because it melted a bit resting on the neutral which I thought was the cause of the blow out, I wasn't replacing the switch, I was investigating as I couldn't see the red light on the switch when I noticed the shower wasn't working properly.

    Thought so, I started with the earth cable as there the most awkward to locate in the switch where its placed on the ceiling, there's no window in the toilet so the hall light was illuminating the toilet.
    The switch looks fine unless there's something I cant see but you wouldn't notice anything untoward on it ie marks or burns
     
  5. Sean_ork

    Sean_ork Screwfix Select

    are you sure you've got the feed & load terminals wired correctly ?

    if you've split one cable across 1 feed and 1 load terminal it will present a dead short when switched on
     
  6. craig mcc

    craig mcc New Member

    No because I never got that far as to mix the wires and I can follow the two pairs easily enough, but was unaware I would trip the switch when I have the RCD on for the other rooms in the flat and was using the hall light to see clearly. So basically if I turn off the mains and wire the shower switch up then turn the power back on I wont keep tripping the switch.
     
  7. Sean_ork

    Sean_ork Screwfix Select

    as was probably mentioned above it'll only trip if you've just turned off the single pole MCB/circuit breaker (leaving the rest of the house on - but only if you allow the incoming neutral to touch the earthed connections on your switch

    turn all of the house power off - rewire the switch, if it still trips then isolate the shower by taking off one leg on the load side of the switch - if it still trips then replace the switch, if it doesn't then the load (your shower) needs investigating
     
  8. craig mcc

    craig mcc New Member

    Thanks Sean, much appreciated, I do like to make sure I get some proper advice before even the simplest task concerning electricity and such like
     
  9. craig mcc

    craig mcc New Member

    thanks for your help
     
  10. flateric

    flateric Well-Known Member

    Looking at that it was a shoddy job in the first place :(
     
  11. Rulland

    Rulland Screwfix Select

    Let me guess!, metal for the masses?, 'cos at the end of the day it's still just a shower pull cord.
     
  12. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Mmmm, and who fitted your new shower?

    Mr. HandyAndy - Really
     
  13. seneca

    seneca Screwfix Select

    Almost certainly all started with loose connections!
     
  14. Rulland

    Rulland Screwfix Select

    My post was aimed at Flats, ie his comment in a previous thread about copper showing.
    Now we all know that no amount of copper showing, within reason, will affect the integrity of the pull cord so long as nothing's shorting.
    All connections should be adequately tight etc, and from the OPs pics I can't really see nothing that would be deemed as unsafe or a risk tbh, anyone disagree?, ie, it's a pull cord, not a consumer unit.
     
  15. craig mcc

    craig mcc New Member

    The guys who did my flat have systematically be found one by one (there were 3) and were given the option off sorting out the **** they called professional work, or have the heads kicked in till there ugly mothers would only recognize them in her memory after I ripped her eyes out
     
  16. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    That's what I like to see.

    Level, cool-headed and fair!

    Mr. HandyAndy - Really
     
  17. flateric

    flateric Well-Known Member


    Diplomacy at its best :D
     
  18. Biochef

    Biochef Member

    Have you tried looking further up under sheath because live looks well buggered
    Earth wire could have melted into live and definitely a slack wire caused that you can't see much of mechanical compression on wire
     
  19. wally

    wally Screwfix Select

    You need to strip that damaged cable a fair way up as you need a shiny copper not a dull one which has been effected by the heat. You might as well change the pull switch for a new one as it must have suffered heat damage (at least on the terminal). You might find some switches a bit bulky to mount it in the pattress, I only use the MK shower pull switch as it is low profile
    http://www.screwfix.com/p/mk-50a-pull-cord-switch-with-neon/12094?_requestid=41826
     
  20. seneca

    seneca Screwfix Select

    How are you feeling Wally, have you started your treatment yet? If so, hope it's going ok mate.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice