Garage consumer unit trips off when switching off garage lights

Discussion in 'Electricians' Talk' started by Karl Taylor, Mar 25, 2018.

  1. Karl Taylor

    Karl Taylor Member

    Led lights are they just the same in wiring set up. Live, neutral and earth cable from what i have in place already? Might consider this option.. ..
  2. JP.

    JP. Screwfix Select

    Sorry Karl - placed it in the wrong topic m8..please disregard my input..:)
  3. Karl Taylor

    Karl Taylor Member

    Final test.

    Took flourecents from different part of garage ceiling and fitted these to the circuit after removing the pendants.
    Made no difference. Still trips the rcd so its not the flourecents.
    It i think is a problem with the load on this two way circuit and a other sensitive rcd.
    Time to get a electrician in
  4. HarDeBloodyHarHar

    HarDeBloodyHarHar Active Member

    Did you change the other switch?
  5. Karl Taylor

    Karl Taylor Member

    Have got at the back of the garage 3 double ip60 lap switches on the wall. One light circuit is wired in to one half of one of them and the the other light in one half of another switch.
    And at the front of the garage is one double switch that i have changed.
    No i have not changed these two switches as they work fine with the pendant lights.

    Just out of curiosity, when the electrician wired the garage consumer unit in could he have miss wired one or both of these light and connected them to let say the socket mcb or something else instead rather than the mcb for the garage internal light? As as a rule doesn't a rcd usually trip on socket over loading etc.

    Its just very odd that the two lights on this two way circuits work fine on light pendants but not on good working flourecents. I think its a over sensitive or over loading circuits ?
  6. Lectrician

    Lectrician Screwfix Select

    Stop guessing and trying random and pointless things that prove very little! What you’re doing is haphazard and pointless. I have stated several tines what the fault is likely to be, you need an electrician to confirm, locate and fix. Don’t blame the RCD. People always blame “over sensitive” RCDs - it is rarely the case.

    Get a decent electrician in.
    PhilSo and Risteard like this.
  7. Karl Taylor

    Karl Taylor Member

    just a up date on this issue.
    electrician has been .
    tested the complete system .
    used a meter and a clamp etc .

    all tested ok.

    but each flourecent is given out a 2amp leakage on start up.

    unable to tell me which flourecent is faulty , but the rest of the system is fine.

    so logic and evidence says it has to be one of the flourecent and its internal components giving out this random spike which is tripping the rcd .

    i am going all the light fittings to led .
  8. Bazza

    Bazza Screwfix Select

    At least you didn’t waste time by changing the switches:p

  9. Karl Taylor

    Karl Taylor Member


    cost of electrician was the cost of average led batten , but at least i know wiring etc is ok so paying for these checks etc .
    somer times in life you just have to pay for things you dont want to pay for, for some body to confirm and tell you what you thought . LOL.
    Bazza likes this.
  10. JP.

    JP. Screwfix Select

    I dont understand the bit about ''2 amp leakage on startup''
  11. Karl Taylor

    Karl Taylor Member

    also said total leakage with the six lights all on was 5.4 amp............
    my thoughts are because its a intermittent fault , it has to be a spike or a surge from one of the units when switching off instead of the current staying in the unit its finding a way back to the board due to a failed component in one of the units , but will be time consuming to test each component on a flourecent etc .

    any way thats what i was told

    no leakage from rest of system
  12. JP.

    JP. Screwfix Select

    Hmmmm - I dont really understand, but thanks Karl.
  13. Lectrician

    Lectrician Screwfix Select

    TBH, sounds like you had dud spark. 2amp leakage? Umm....
  14. Karl Taylor

    Karl Taylor Member

    To be honest, i doubt i get him back as he picked fault with a few things saying its a fancy installation. Fuse box is a bit crowded. Bla bla bla . Also said i had a 20amp draw some where with every thing off but couldnt find that. Dont think he could interpret what his equipment was saying . Guess easy money for him for a few hours on a saturday to tell me what i already new or may be wanted to confirm i new . ....
  15. Risteard

    Risteard Well-Known Member

    2A leakage my balls.
  16. Bazza-spark

    Bazza-spark Screwfix Select

    Karl, if I have read your post correctly, he is talking complete rubbish. In your first post you stated

    [QUOTE="Karl Taylor, post: 1590097, member: 181573"I suspect its just a power surge as doesn't do it all the time? Or is there something wrong or do i need higher values of mcb in the fuse box in the house or is it a faulty garage rcd unit?

    House supply fuse to garage is a mcb rated at 40. This does not trip out.

    Garage fuse box rcd says 63A 30 ma 240volt
    This is what keeps tripping out. the lights mcb on this unit does not trip out.

    I have tested the garage rcd by pressing the test button and it works fine .

    Think might have to get electrician out if not a simple fault? any advise welcome.[/QUOTE]

    1. Given you have a 30mA RCD there is no way he could measure 5.4 amps leakage with all the lights on. They would have tripped long before that.
    2. How did he measure the 2A leakage at start up, because again, the RCD would trip long before that?
    3. Couldn't trace a 20A draw with everything switched off?

    He is useless. You need a trained, qualified spark.

    Kind regards
  17. HarDeBloodyHarHar

    HarDeBloodyHarHar Active Member it's probably the other switch! :D
  18. paleosparkler

    paleosparkler New Member

    Carry out an ir test on the circuit.
  19. RzB

    RzB Member

    Could it be a confusion between A and mA? 2A is just silly.
  20. Bob Rathbone

    Bob Rathbone Screwfix Select

    Have you had someone look at that?:)

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