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  1. Wolstej
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    Wolstej EF Member

    Location:
    Nantwich
    Can anyone help us with a problem? Since the summer one of our RCDs has been tripping every night at the same time (22:52 before the clocks went back, 21:52 ever since). There are two RCDs in the switch board: the one that trips has an outside workshop, upstairs sockets, downstairs lighting and the door bell. The house was completely rewired in 2012 so everything is (or was) bang up to date. At first we suspected the RCD so both were duly changed but to no effect. We also suspected the boiler which was quite old; today we had a brand new one fitted but still the RCD tripped. A 'neutral-Earth' fault has been mentioned a couple of times but what seems really strange is the regularity of the problem, the same time every single night. We cannot think of a single thing that comes on or goes off but surely it has to be something with timing circuitry, a standard fault wouldn't be so predictable. Could something on the other RCD be causing it? But if so, why doesn't that side trip as well?

    If anyone has any ideas we'd love to hear from you because we really are at ours wits' end now and do not know where to turn
     
  2. Pat H
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    Pat H Don't ask, get an Electrician in.

    Location:
    Ware Herts
    Business Name:
    Sparks of Intelligence
    I'd be tempted to turn off all but one of the circuits a few minutes before the trip happens. By a process of elimination you should be able to isolate the circuit that is causing the trip.
     
  3. Wilko
    Online

    Wilko Electrician's Arms

    Location:
    Berkshire
    Business Name:
    Wilko Electrics
    Hi - sorry to hear you've a problem. It is intriguing that it trips at the same time ea night. A few qs ... the RCD having tripped and been reset, works ok for 24hrs? And everything in the house works as you think it should (i.e. no known faults) ? Also, do you / did you have storage heaters?
     
  4. Leesparkykent
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    Leesparkykent You Rock Gmes Staff Member Trusted Advisor

    Location:
    Kent
    There must be something that's timed to turn on or off at that time. your new boiler is it a combi or do you have a hot water cylinder?
     
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  5. Wolstej
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    Wolstej EF Member

    Location:
    Nantwich
    We haven't actually tried doing this at the circuit board, definitely worth a shot. Many thanks
     
  6. Wolstej
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    Wolstej EF Member

    Location:
    Nantwich
    That's right, we reset the RCD and it's absolutely fine until the next night. There are no other faults that we know of; we have a combi boiler and radiators
     
  7. Wolstej
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    Wolstej EF Member

    Location:
    Nantwich
    Hi. It's a Worcester Bosch combi boiler. We have nothing else on a timer. Thanks
     
  8. Wilko
    Online

    Wilko Electrician's Arms

    Location:
    Berkshire
    Business Name:
    Wilko Electrics
    Can you quickly check the on off time on the heating programmer ?
     
    • Like Like x 1
  9. buzzlightyear
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    buzzlightyear Electrician's Arms

    Location:
    star command
    you will need a lot a detective work for this one, if you have not got any test gear the only way is start dropping the mcbs , before that time of fault to see which mcb has the fault .
    before the rcd trips why did you have the both rcd changed .
     
  10. Wolstej
    Offline

    Wolstej EF Member

    Location:
    Nantwich
    The new boiler and wireless thermostat were fitted literally today! At the moment it's on manual so we're just going to turn it on and off when we need to. We've had the log burner going tonight so the boiler's been off since 17:30. J
     
  11. Wilko
    Online

    Wilko Electrician's Arms

    Location:
    Berkshire
    Business Name:
    Wilko Electrics
    Perhaps leave it off till after the witching hour and one thing eliminated:)
    Has that time already passed?
     
    • Like Like x 1
  12. Wolstej
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    Wolstej EF Member

    Location:
    Nantwich
    Thanks, we'll definitely try this but it'll take a few nights before we get a result! I agree, why DID we have the RCDs changed! It seemed worth a try at th time but you have to trust what someone suggests, at least to start with!
     
  13. Wolstej
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    Wolstej EF Member

    Location:
    Nantwich
    Will do. But would you agree it must have something to do with a timer? It's just too regular to be a random fault!
     
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  14. westward10
    Online

    westward10 In echoed steps I walk across an empty dream. Electrician's Arms

    Location:
    Northamptonshire
    They normally trip with good reason and are generally replaced when they don't.
     
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  15. Wolstej
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    Wolstej EF Member

    Location:
    Nantwich
    I know, I should be grateful that they're keeping us safe but we can't go on like this forever!
     
  16. Leesparkykent
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    Leesparkykent You Rock Gmes Staff Member Trusted Advisor

    Location:
    Kent
    It happens every night at the same time without fail?
     
  17. PEG
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    PEG Trusted Advisor

    Location:
    Manchester
    I think the time has arrived,to know more about your installation,as not knowing if the equipment fitted is working correctly or not,could hamper estimating any fault.
    Dependant on the origin,it could even be a neighbours fault...
     
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  18. Jacek Buczak
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    Jacek Buczak EF Member

    Location:
    Redditch
    Business Name:
    J&B Electrical Service
    Hi all yes long time ago I had the same problem ,customer said the electricity out how combi boiler start in nite time.After watching I found fault so combi boiler was installed in garage high on the wall fell out of the outflow plastic pipe and water go after wall straight to socket outlet under boiler,after how I open socket outlet half water was inside :).Best Regards
     
  19. Murdoch
    Offline

    Murdoch Electrician's Arms

    Location:
    Woking
    Dare I ask if anyone had actually done any proper tests on your house? Who changed the RCD's? What is the background earth leakage that the house has?

    Many questions.....
     
  20. davesparks
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    davesparks Trusted Advisor

    Location:
    guildford
    Well that makes absolutely no sense at all, any chance of translating in to English?
     
  21. davesparks
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    davesparks Trusted Advisor

    Location:
    guildford
    I'm curious as to what logical thought process lead to the RCD being replaced?
    The fault occurs at exactly the same time every day, so unless your RCD has an in-built real time clock then I can't see how anyone thought it could be causing this issue?

    The biggest clue here is that the fault occurs at a specific time,
     
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  22. Jacek Buczak
    Offline

    Jacek Buczak EF Member

    Location:
    Redditch
    Business Name:
    J&B Electrical Service
    Very sorry for writing so incoherently, I see that the others only when reading apparently did not have so much knowledge as some have here I should not have to lend - once again sorry.Bye
     
  23. buzzlightyear
    Offline

    buzzlightyear Electrician's Arms

    Location:
    star command
    had call out to customer on day the boys in blue British gas fitted a brand new Worcester bosh boiler
    they fitted 2 new pc boards could not find why the boiler was not working they rang
    Worcester bosh the engineer he came, told her their is nothing wrong with the boiler he told the customer, and disconnect from fuse spur.
    get you own spark in ,I found the boy is in blue put in a power shower and the boiler on the same s/f spur on 3amp fuse
     
  24. dmxtothemax
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    dmxtothemax Regular EF Member

    Location:
    Australia
    Business Name:
    David Haddock Electronic Repairs
    Could also be a neutral problem with an adjacent property,
    causing currents to flow via the common earth into your system.

    try what was suggested in post number 2.
     
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  25. Lucien Nunes
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    Lucien Nunes Mercury Arc Rectifier Trusted Advisor

    Location:
    London
    For the RCD to trip there usually has to be a fault on one of the circuits that it controls, however the trigger factor that governs when it trips might be on the other RCD or even outside your installation.. E.g., if you have a neutral-earth fault downstream of the RCD, the higher the neutral-earth voltage at your supply terminal the more likely the RCD is to trip. If there is a heavy load surge or transient from a nearby installation that momentarily pushes up the N-E voltage, it will be your RCD that trips because you've got the N-E fault, not the RCD at the installation generating the surge.

    Therefore I would not waste time looking for some mystical timed device that you don't think you own, until you get some electrical testing done to discover whether there are any latent faults and what operating conditions your RCD is working under.
     
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  26. PEG
    Offline

    PEG Trusted Advisor

    Location:
    Manchester
    As above,testing is required...or authorities need to be advised of an accomplished intruder,with a torch,a watch and an 8K resistor...
     
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  27. dmxtothemax
    Offline

    dmxtothemax Regular EF Member

    Location:
    Australia
    Business Name:
    David Haddock Electronic Repairs
    Wiring abnomalities can cause issue's with ELB,s.
    Especially if the neutral and earth systems are not 100%.
    This was not the case without ELB's.
     
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