Puzzled by 1G switch!

Discussion in 'Electricians' Talk' started by s.bury, Jul 4, 2015.

  1. s.bury

    s.bury Member

    Hi, my kitchen switch fell apart- a simple 1 G switchover two ceiling lights. My missus popped out and bought an intermediate switch from sf 48139. I tried this, neutral already in cable block, so tried live to L1 and L3, no luck! In fact I then tried all variations of L2 to L3, L4 etc but no luck either. Rest of the lights and mcb ok....am I missing something obvious? Ps tried live cables together and no light either, just seems dead. Cables and connections all look ok. Any advice appreciated as no sparks local to me answering at the mo and I'd love to get it sorted! Cheers, Steven
     
  2. PaulBlackpool

    PaulBlackpool Screwfix Select

    Just DIY but might be able to help. Was it an intermediate switch that broke?. If not just replace it with the type that broke and it should be easy. What do you mean by a simple switchover?. On /off or changeover? Do the two ceiling lights normally come on at the same time?
     
  3. Lectrician

    Lectrician Screwfix Select

    An intermediate can be used as one way (and two in fact), but it's expensive to do so.

    As you have tried joining the the switch pair together and still get no light, it sounds like the fault is elsewhere. Did you have no light, and assume it was the switch, so tried to repair the switch by taking it apart, hence your "fell apart" comment?
     
    FatHands likes this.
  4. s.bury

    s.bury Member

    Hi, I noticed the toggle switch has dropped out! It worked fine prior to that. The intermediate switch was bought for me but it was a 1 g switch, turning on both ceiling lights at the same time. I was puzzled as why connecting the two live wires didn't work ie light up. Any tips to problem solve?!
     
  5. s.bury

    s.bury Member

    It's a simple on or off to two lights. Thank you for your consideration guys.
     
  6. The two 'live' wires you are referring to - they are both sleeved 'red', yes?

    And these were the ONLY two wires connected to that old switch?

    In which case, if joining these two wires has not made the light come on, then - as Lec says - there is a further fault elsewhere because it should have come on.

    (By the way, only one of these wires is actually 'live' - the other is a 'switched live'. That's just free info for you - obviously don't touch either of them...)
     
  7. s.bury

    s.bury Member

    Lol- that's what I feared! Does this mean taking up the floor etc etc to go back to the junction box to find loose wire ? Grr! I hate looking for thIngs that I don't know exactly what I am looking for! Where would u guys start?- the cu or the switch end?! I am a DIY er - do sparks like faffy jobs like this, as I am worried I get billed for several hours ! I appreciate your thoughts once again. Steven
     
  8. PaulBlackpool

    PaulBlackpool Screwfix Select

    If the lights worked OK before you broke the switch then it is very likely that the remaining problem will be with the wiring to the switch at the switch position. It is highly unlikely that there will be fault elsewhere unless you have pulled at the wires and loosened a connection elsewhere. Are you positive that the remaining lights on the circuit work and that the relevant MCB and RCD have not tripped? Do you have any means (multi-meter or neon screwdriver) to see if there is any current in the wires at the switch position?
     
  9. peter palmer

    peter palmer Screwfix Select

    Did you switch off to change the switch? maybe its not come back on again when you switched back on, but I would have thought more than one would stop working. Maybe there is a short that has damaged the switch when it was switched on and there is a fuse elsewhere, who knows, you need a tester.
     
  10. s.bury

    s.bury Member

    Tried a different switch, mcb checked, cu checked...tried my neon sparky screwdriver in a number of orifices....chuff all! Went to see a neighbour who is a spark as I now know my limitations! Cheers all for the pointers and ideas. Steven
     
  11. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Have you been into any ceiling lights wiring?

    Mr. HandyAndy - Really
     
  12. s.bury

    s.bury Member

    No- lights have been working fine for the last 5 years...I ve never had an electrical problem that I couldn't figure out before as I am quite careful and methodical about DIY . If my spark fixes in in 2 mins I'll be mightily peeved that I couldn't!!
     
  13. Pfft, I doubt your sparky will take that long... :p

    Let us know what the issue was, pleeeeez.

    (I have a £iver on it being a blown lamp... :rolleyes:)
     
  14. s.bury

    s.bury Member

    Well a week later. The sparkie who is a neighbour failed to turn up this week. Perhaps he assumed I wanted a freebie? I never ask for favours off folks btw. I rang another chap but he's retired and no answer on the third. So back to plan B I have a multimeter can I use it to see if one of the wires is live? If not? If so? Sorry for being a pain!! Steven
     
  15. Oooookkaaaayyy...

    The following is best done with a simple mains tester screwdriver, actually, since that only needs you to touch one wire to test, whereas a meter will need both probes to be used. But, assuming you only have the meter...

    If there are only two wires present in total, then one will (er, should) be permanently 'live' and the other not. (The other one becomes live when the switch is 'on', 'cos it's now joined to the 'live'.)

    Ok, first, what other lights are run off that MCB? And are you sure that they work? Sure?! 'Cos there's a chance the MCB is faulty, for instance.

    Assuming the MCB is working chust fine, then you need to check for mains voltage at these wires, bearing in mind only one should be live. So, set your meter to AC Volts and higher than 240V (good chance it has 750V or 1,000V?) and touch one probe to an good known 'earth'. There should be an earth inside that switch's back box - is there?)

    Ok, find 240V on one wire? And are you still alive? Good.

    Ok, what to try now...

    Right, remove the lamp (bulb) - can you access the terminals in there using your meter? Ok, one of them should go 'live' when you join the two switch wires together, but not before. (Ie - you get 240VAC between it and the earth you've been using.)

    Result?

    Ok, if you have 240VAC at one switch wire, that means your MCB is fine, as is the wire from the CU to that switch. If you also get 240VAC at the lamp holder, then you know what that means too...

    Ok, if you have 240VAC at one terminal at the lamp holder (with the switch wires joined) then try and see if you also get 240VAC across the two lamp holder terminals - you should.

    If you don't, that would suggest that the other terminal - the neutral - is faulty somehow. And that would be weird.
     
  16. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Did you disturb the 'neutrals already in block' ? How many neutrals ? Has one come loose ?

    If I had a £..........

    Mr. HandyAndy - Really
     
  17. s.bury

    s.bury Member

    I've followed the detailed advice- I am very grateful for this.

    At the back box and wires there is no voltage detected at either
    'Live' wire nor the earth or neutral so all quite dead !

    Mcb at the cu seems fine and all other lights on this mcb work fine.

    I am now guessing a crawl through my 35 deg C loft filled with ultra itchy wool insulation is needed on the off chance a wire has escaped the junction box someplace by itself?! I, ve never been stumped by a 1 g switch before....this is embarrassing!

    Ps I spent several hours rubbing leather oil into a cream sofa. It now looks like it was salvaged from a house fire ***. Sometimes everything seems like a sh&&&y job! So several hours oiling up and erotically massaging a sofa for no reason except to make it look considerably worse.
     
  18. Man, I didn't know life could get that bad... :p

    Any chance of posting a photo of these wires as they come in the back box?

    It chust sounds weird for a wire to give up like that.

    I guess it does now mean a crawl... Hopefully there's something simple like a JB there with a loose screw.
     
  19. PaulBlackpool

    PaulBlackpool Screwfix Select

    If all the other lights on the circuit are OK maybe somebody has introduced a fuse some where which has blown. Could these lights be powered from the kitchen ring circuit and fused down to three amps by a fused connection unit?
     
  20. dale76uk

    dale76uk Member

    My first thoughts were a FCU somewhere for the lights as the OP States the neutrals in a block presumably in the back of the switch. However, I think there maybe more to the story than we think. Typically a broken light switch wouldn't cause a L-E or L-N fault. CHECK ALL FCU
     

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