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RCD socket outlet.

Former Community Member
Former Community Member
Hi all,
Any comments on this one most welcome!
A customer wants me to replace an existing one gang 13 amp socket outlet with a double.
The problem is that there's no rcd protection there, so i'm thinking that as I am in effect adding a socket outlet I should fit an rcd protected one?
If I were replacing like for like it wouldn't bother me at all but the fact it's going to be a double makes me think an rcd protected one is the thing to do, just seems a bit ott to fit one rcd protected socket when there are probably 20 others that aren't rcd'd!
  • 0

    John Peckham:

    Andy


    Wrong about the fault current rating by a long way.




    BS 7288:2016 5.4.8: Standard values of the rated conditional short-circuit current (Inc) The standard values of the rated conditional short-circuit current Inc are as follows: 1 500 A – 3 000 A.

    Different power factors apply for each value. So yes, the two types of RCD are not to exactly the same spec, but it would be an odd installation where a 13 A SRCD was vulnerable to a higher PFC.

  • 0
    Reading this thread is the HSE not keeping up with the current regulations, thinking about  electrical recommends for HP Washers and stm HP HW cleaners . A 13 amp socket with a built in RCD can form part of a fixed installation , but the number of these sockets I found seized (larger wattage power washers) ,can't pull put the plug top due to burnt pins , I was always careful to recommend or demand replace with a 16amp RCD outlet. The HSE leaflet

    below:


    www.hse.gov.uk/.../pm29.pdf

    jcm
  • 0
    So I am in the clear using a masterplug RCD adaptor in a socket outlet? To quote the manufacturer " ideally you would use an RCD adaptor with any electrical appliance"

    For those suffering with BS paranoia, the number is = 7071 1992.


    Regards, UKPNZap


  • 0

    jcm:

    Reading this thread is the HSE not keeping up with the current regulations, thinking about  electrical recommends for HP Washers and stm HP HW cleaners . A 13 amp socket with a built in RCD can form part of a fixed installation , but the number of these sockets I found seized (larger wattage power washers) ,can't pull put the plug top due to burnt pins , I was always careful to recommend or demand replace with a 16amp RCD outlet. The HSE leaflet

    below:


    www.hse.gov.uk/.../pm29.pdf

    jcm




    The old ones are rated 13 amps resistive loads and 3 amps inductive loads, the new ones are 13 amps for both.


    The old ones do not like garden power tools and equipment like shredders with induction motors.


    Andy Betteridge.

  • 0

    UKPN:

    So I am in the clear using a masterplug RCD adaptor in a socket outlet? To quote the manufacturer " ideally you would use an RCD adaptor with any electrical appliance"

    For those suffering with BS paranoia, the number is = 7071 1992.


    Regards, UKPNZap


     




    Is your earthing and bonding in place?


    Actually most garden power tools like mowers are now double insulated so getting a shock off a faulty electric heater in a bedroom whilst mowing the lawn in the garden is not going to be a problem.


    Andy Betteridge.

  • 0

    Sparkingchip:




    UKPN:

    So I am in the clear using a masterplug RCD adaptor in a socket outlet? To quote the manufacturer " ideally you would use an RCD adaptor with any electrical appliance"

    For those suffering with BS paranoia, the number is = 7071 1992.


    Regards, UKPNZap


     




    Is your earthing and bonding in place?


    Actually most garden power tools like mowers are now double insulated so getting a shock off a faulty electric heater in a bedroom whilst mowing the lawn in the garden is not going to be a problem.



    Class I or II is irrelevant. The risk is mowing over your cable, or putting your hedge trimmer through it. No problem with your double-insulated sword of doom, 'cos immediately, it has been disconnected. It's when you pick up the live end whilst wearing bathing knicks and standing on a moist lawn that your troubles start.

  • 0
    It's not irrelevant. Think it through. 


    If you have a Class I appliance there can be a high touch voltage on its case from a fault on the other side of a RCD protecting it.


    Andy Betteridge
  • 0

    That is exactly the point I was making, you cannot connect a RCD to a circuit and installation that is not adequately earthed and bonded or else a fault elsewhere in the installation may raise the voltage of earthed equipment downstream of the RCD to dangerous levels, a RCD does not remove the requirements for basic and fault protection along with the requirement to mitigate touch voltages.



    The point I was attempting to make was than even in a fully correctly earthed & bonded installation a fault elsewhere can raise the exposed-conductive-parts downstream of the RCD (as elsewhere) to dangerous levels - e.g. >115V for 5s in a TN system or 230V for 1s in a TT system -  the 'mixed disconnection time problem' isn't just something for inadequately earthed/bonded installations to worry about.


    There is some advantage in having all your RCDs close to the MET (with the minimum of parallel paths on the c.p.c.s) - in that faults on your circuit are covered by the rapid disconnection time of your RCD and faults on other circuits shouldn't raise the potential on your c.p.c. relative to the MET (where both your c.p.c. and main bonding are connected) - but BS 7671 doesn't clearly advocate that approach (although perhaps hints at it in section 701).


       - Andy.
  • 0
    Question.


    Did the JPEL committee ever discuss making a single upfront 30 mA RCD a requirement for all domestic installations? Rooting around the internet I have seen a comment that they did, which would make sense as it makes for the safest installation.


    Another question.


    When was the requirement for a maximum touch voltage of 25 volts for a construction site installation dropped and why?


    Andy Betteridge 


  • 0

    AJJewsbury:




    That is exactly the point I was making, you cannot connect a RCD to a circuit and installation that is not adequately earthed and bonded or else a fault elsewhere in the installation may raise the voltage of earthed equipment downstream of the RCD to dangerous levels, a RCD does not remove the requirements for basic and fault protection along with the requirement to mitigate touch voltages.



    The point I was attempting to make was than even in a fully correctly earthed & bonded installation a fault elsewhere can raise the exposed-conductive-parts downstream of the RCD (as elsewhere) to dangerous levels - e.g. >115V for 5s in a TN system or 230V for 1s in a TT system -  the 'mixed disconnection time problem' isn't just something for inadequately earthed/bonded installations to worry about.


    There is some advantage in having all your RCDs close to the MET (with the minimum of parallel paths on the c.p.c.s) - in that faults on your circuit are covered by the rapid disconnection time of your RCD and faults on other circuits shouldn't raise the potential on your c.p.c. relative to the MET (where both your c.p.c. and main bonding are connected) - but BS 7671 doesn't clearly advocate that approach (although perhaps hints at it in section 701).


       - Andy.

     




    Maybe the saving grace is that bonding is more effective in reducing touch voltages in TT installations than in TN installations.


     Andy Betteridge 

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