Not my day today

Discussion in 'Electricians' Talk' started by AJStevens, Jun 22, 2017.

  1. AJStevens

    AJStevens New Member

    Hello,

    So had a powercut earlier today, was a bit strange, most things went off, but for a few seconds a number of items tried to come back on repeatedly, I looked at a mains extension with an LED on it go off, on, off, on, off, on, off, on... you get the idea.

    I was a bit worried and thought about getting to the consumer unit and flicking it all off, however, never experiencing that kind of powercut before, self preservation told me to keep away from it, fearing it might blow up in my face or something.

    It finally stopped, and was off, I gingerly approached the consumer unit and lifted the semi-transparent cover to look at the RCD and MCBs, all were in the active positions. Checking my smartphone, there was indeed a powercut around my area (though had been reported a couple of hours earlier but I had only just been effected, great), estimated fix was in an hour or one and a half.

    Shortly before the hour mark, the power came back on, everything came back to life, then a minute or two later, it all went again. I figured they were still working on it, and waited at least half an hour or more, while passing by the consumer unit, I took another peak, the RCD had tripped now... oh... I reset it, and power came back on.
    Darn it, power had probably been back a while... I then got a text to say they'd fixed the power cut by rerouting power, ok, so maybe hadn't missed out on much power usage.

    Everything seemed fine... then, guess what? The RCD tripped... hmm.. that's annoying, I switched it off, and reset it, everything back on again... I reset the clocks on the few remaining devices that don't have battery back up and carried on.

    A little while later... the RCD trips again... ok somethings not right... I flick it off, leave it off for 5 minutes, then flick it back on... I look around... washing machine isn't on (old washing machine was the problem before after the Mrs overloaded it and broke it... fantastic, that cost me a new washing machine), Fridge seems ok... I turned off any mains sockets not required in the kitchen at the wall (one for the Kettle for example), everything else is working, nothing I can think of would take a while to draw more power and trip.
    I'm hoping the RCD is just a bit sensitive from the power cut and having it off for a while might have sorted it.

    A while later, and two seconds after the Mrs turns OFF the hall light, it goes again, though this maybe pure coincidence, but now I'm really fed up, the power cut has messed up the RCD or some appliance that is causing it to trip... but not immediately... fantastic, just what I need right now.

    Ok... I lift the consumer unit flap again, flick everything off, RCD, MCBs, including the large red flip switch for the "main" mains, and sit there watching my phone for 5 mins, grumbling to myself.

    I flick the main power back on, and the RCD and slowly add each MCB again, first the lights, ground and first floor as these don't use the RCD, then the cooker, the shower, the ground floor, for the moment I leave upstairs off, perhaps I can narrow it down to either downstairs or upstairs, or both/neither.

    So, while waiting I type up this post on the forum.

    Before, I had RCD constantly fail (before the washing machine incident), going back a while now, so don't remember it fully, I presume since I was fairly certain it was the RCD it must have been tripping with the MCBs off or something, or not a specific MCB setting it off, anyway... I looked at the MK RCD 30a and found the part on Screwfix, purchased it and turned off the power in the consumer unit by the large red power switch and proceeded to take the cover off, and replace the RCD with the new one... this took me quite a while due to having to summon courage a number of times during the process, e.g. removing the cover, having to remove the old RCD, install the new one, replace the cover, like the consumer unit was radioactive (as a non-electrician, a good level of fear/respect to have I thought), not helped by the fact this is located in the hall, not far from the ceiling, so having to stand on tip toes on the stairs to read and reset the RCD normally, obviously for this extended period I had to use a step ladder or balance between the stairs and the hall unit (shoes, letters, that kind of thing). Managing to complete the swap out, and not letting my nerves get the best of me (get electrocuted, leave a widow and fatherless kids), my theory had paid off, the RCD was not tripping, everything was on and staying on, once my heart had lowered below my throat to its normal location, I felt quite chuffed, sense of satisfaction, independence and yes, "a man", I had managed to do something myself.
    Dad passed away a number of years ago due to cancer, when he was around, he did it all, though I did know how to wire a plug, I mostly did Network cabling (RJ45 crimping and the like). Though, since his departure I have also managed to replace a light fitting or two, again feeling like a little win each time.

    However, I'm dreading to have to do that again.... but its looking like a distinct possibility... best get an electrician this time, but if that's all they end up doing, replacing the RCD and charging me a fortune for it, that's going to bug me.. since I had managed to do it myself before.

    Given the events of today, what's most likely, the RCD to be faulty, or I have to work out what appliance or extension is now damaged by the power cut and tripping the RCD, but isn't doing it immediately of course, because nothing is ever easy.

    So far... not tripped again... no power to anything upstairs though... at least its nothing downstairs doing it, although maybe not been long enough... could the full consumer unit switch off for 5 mins have sorted it?
    Mrs has been using the lights downstairs, on, off, on, off, and used the Microwave... not tripped again.

    Want to have upstairs power back on... but don't want to have to worry about it tripping in the night.

    AJS
     
  2. terrymac

    terrymac Screwfix Select

    hi ,so you replaced the RCD today or months ago ? and at the moment all MCB ,s are in the on position ?
     
  3. Sparkielev

    Sparkielev Screwfix Select

    To be fair you shouldn't be messing with rcds not really knowing what you are doing
     
    Shaggy and terrymac like this.
  4. AJStevens

    AJStevens New Member

    Think it was years ago I changed the RCD, probably not long after I was the only man of the family.

    The upstairs MCB is still off, putting it back on now though.
     
  5. terrymac

    terrymac Screwfix Select

    if I were you i would contact your supplier and complain that since the power cut your RCD tripped and is continuing to do so after re set.throw the ball in their court . you should not be changing it yourself .after an RCD is fitted it has to be tested to ensure it meets disconnection times and current limitations ,which requires very expensive testing equipment. regards terry.
     
    Sparkielev likes this.
  6. AJStevens

    AJStevens New Member

    Advice on their website for any suspected problems with appliances, fuse box or wiring is to get an electrician, they have a number to assist you find one, that's all by the sounds of it, will try that tomorrow I guess.

    Wonder if it was one of the MCB's I replaced actually and not the RCD, I have a vague memory of thinking to try swapping them to see if the problem followed the MCB or the circuit then finding it more trouble than worth once I opened it... the MCBs are fitted leaning a bit, not perfectly straight (OCD alert), so may have been awkward to do that and I just replaced it with a new one I think, that could be wrong though, damn my awful memory.
     
  7. terrymac

    terrymac Screwfix Select

    so are all circuits on now and all working OK ?
     
  8. AJStevens

    AJStevens New Member

    Yes, but only just put the upstairs on... it had been more than an hour so decided the downstairs was likely "ok", could be something upstairs that takes a while to cause it to trip, previous times it wasn't an "instant trip".
     
  9. MGW

    MGW Screwfix Select

    At home it is normal to have bouts of the RCD tripping, then can go for years without a trip, it's been like that since the 1990's when first fitted, any spikes can trip the old type RCD's that is normal. New ones are electronic and have things built in to stop a spike tripping them, but quite normal for old type, often the spike caused resetting one RCD will trip the other one if all MCB's have not been switched off first.
     
  10. Bob Rathbone

    Bob Rathbone Screwfix Select

    The DNO's District network operators, use a system on the high voltage 11kV distribution, that when a fault trips a breaker, the system automatically resets itself, moving down the line with breaker closures until the breaker trips again. This method allows them to quickly restore power to a line without a fault, but at the same time isolate any faulty branch. The unfortunate side effect is that the consumer suffers the rapid on, off, on, off, that you describe. Some electronic items such as my central hating boiler receiver, do not like this and may be damaged. Your RCD with any electronic internal components may have suffered, or you just might have a fault somewhere in the installation. You have changed the RCD and the fault persists. Time to call a sparks as the installation will require testing to locate the fault.
     
  11. AJStevens

    AJStevens New Member

    Thanks MGW, that's discouraging to hear, these days, the Sky TV, games consoles, broadband router, etc don't take kindly to power outages, hmpf, may have to divert funds to some strategic small UPS devices around and/or see if my consumer unit of MK RCD and MCBs should be updated.

    Thanks Bob, very informative, that makes sense, I won't panic the next time that happens (but might want to flick off my power myself to protect devices).
    I changed either the RCD or an MCB years ago when it was being a bother.


    So far... so good, touch wood, since last night... I put the upstairs MCB back on... as a precaution I turned the aircon (split Fujitsu) off. It was active at the time and would continue running, and turned it off at it's fused switch box beside it too, everything seemed ok for a further 45 mins, so put that back on and everything still ok and has been so far thankfully. Hoping maybe the full off and on of the consumer unit has settled it.
     

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