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Outdoor RCD Socket wont reset

Discussion in 'Electrics UK' started by colin H, 10 Mar 2021.

  1. colin H

    colin H

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    Hi Folks ,

    I have an outdoor RCD socket , like this one

    https://www.screwfix.com/p/british-...JU-n6Kow6S2Fshd84cwaAtRrEALw_wcB&gclsrc=aw.ds

    Its running my pond pumps and some outdoor lighting . Normally pulls around 200w . Its been installed for around 10 years without any problems .

    This morning , I noticed it had tripped , and it wont reset , even with the appliances unplugged . Ive re-routed the pumps into another RCD , in my garrage , and they seem to be running ok .

    Think its possible that the pump got blocked and overheated , causing the trip .

    Will I need to replace the RCD socket , or is there a way to reset .

    Thanks .
     
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  3. Aragorn84

    Aragorn84

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    sounds like the socket is just broken...

    These RCD sockets are kinda nasty anyway. They also designed such that they trip in the event of a power failure, which isnt really ideal. I would fit a standard one and make sure its protected at the supply end, preferably by its own RCBO.
     
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  4. EFLImpudence

    EFLImpudence

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    The tripping on loss of power (active RCD) is a safety feature for power tools but obviously not wanted for pools etc.

    If there is RCD protection at the supply end then may as well fit a plain socket.


    Also, some (all?) won't work without an earth connection - check it is sound and while in there see if it is wet or has a resident slug.

    Have you had any rain lately? :)
     
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  5. ericmark

    ericmark

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    Link is to a passive RCD which will remain on after a power cut, but many are active which means no power and it will not reset, two reasons for active, one is power tools will not auto restart the other is volt drop could be over the amount required to work the electronics, so designed to fail safe.

    I will guess you really have an active RCD and simply no power to socket.
     
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  6. JohnW2

    JohnW2

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    Indeed.
    Can you clarify what you're saying here? Do you really think that 'voltage drop' (I presume you mean 'in normal use') could be high enough to impair the functioning of the electronics of an RCD?

    Kind Regards, John
     
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  7. ericmark

    ericmark

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    If we assume a short to earth, then the line volts will clearly dip, and at the CU the did will only be a few volts, but at the end of the cable there could be 0.9 Ω and still be within volt drop for 13 amp supply, which can mean less than 100 volts at the socket on a 32 amp supply type B without the magnetic part of the trip being activated, I know unlikely, but with active type if that happens either it trips on under voltage or on earth leakage so fails safe. The other is loss of neutral so nothing to work the electronics.
     
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  8. JohnW2

    JohnW2

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    If I understand you correctly .... are you arguing that all RCDs should be active ones (which would obviously result in problems with freezers etc., and maybe a lot more, in the face of power cuts)?

    As far as I am aware, all RCDS these days contain electronics which have to work for them to trip. An L-E 'short' close to the RCD will reduce the L-N voltage at the RCD to close to zero, hence removing power supply to the electronics. If, in that situation, something (presumably a capacitor) maintains voltage to the electronics for long enough for the device to trip, then the same could/would presumably be the same for both active and passive ones - but, if not, then a passive one would also suffer from the problem you are describing, wouldn't it (and therefore perhaps "should be active", by your reasoning?) - or am I misunderstanding you?

    Kind Regards, John
     
  9. colin H

    colin H

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    Thanks for the replies , everyone - much appreciated .

    Just a bit more info , so hopefully I can get the correct replacement

    We did have heavy rain , last night - so water could have got in . Will have a look at the weekend , when I have more time .

    The pumps and lighting run through a fused switch box and then into the RCD socket . At the supply end I have an old fashioned consumer unit and fuse box .

    With this in mind , would a standard outdoor socket be ok , or would it be safer to keep the RCD protection . If so , can anyone reccommend a replacement unit , please ?

    Thanks again !
     
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  11. securespark

    securespark

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    Pictures please!
     
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  12. colin H

    colin H

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    IMG_20210310_162423738_HDR.jpg IMG_20210310_162244536_HDR.jpg hope this helps . Forgot to mention , we had a smart meter installed recently , and part of the old consumer unit was replaced .
     
  13. securespark

    securespark

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    Wanted to see if you had any RCD protection at all.

    If you haven't, it's best to use an RCD socket.

    But is the socket faulty, or the supply to it?

    Have you proved the supply?
     
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  14. RF Lighting

    RF Lighting

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    I agree with securespark. First job is to prove that there is still an electricity supply to the socket. It sounds obvious but it won’t reset without one.
     
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  15. colin H

    colin H

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    The RCD is a spur from an indoor socket . The parent socket is working , but I'll check the wiring at the weekend .
     
  16. ericmark

    ericmark

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    I am trying to think of a way to see if passive or active. Or a safe way to test. I think very likely simply lost power, and have in last 6 months replaced a socket for my daughter twice due to water ingress. So sockets do fail.

    Since you have no RCD's buying one is not that expensive so the simple option is to swap socket then if turns out not socket use it else where.
     
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  17. JohnW2

    JohnW2

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    I suppose it depends on what one regards as safe - and what the OP would be comfortable to do, but ... if one disconnected it and powered it up (e.g. with a length of flex connected to a 13A plug, plugged into a known-working socket) then one would be able to find out both whether it was 'working' (to the extent of being resettable when powered) and, if yes, whether it was active or passive (by removing its power).

    Kind Regards, John
     
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