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New EICR - "No earth bond to some socket boxes: C2"?

Former Community Member
Former Community Member
I have a new EICR which has the observation "No earth bond to some socket boxes: C2".


I have checked continuity between all faceplate mounting screws and the earth of the socket. They are all connected, i.e. the back box is at least earthed by the screw if not with a tail internally (I have not removed the front plates of any sockets). The earth of each socket is connected to the ring.


While it is best practice, is it a requirement of the regulations that a tail is connected internally?


many thanks



  • 0
    In a house for a repair to a socket, the wifie told me that she was getting a shock from the kitchen light switch; it was a an older installation with VRI singles in metal conduit and boxes, with no earth provision but metal fixing screws at the light switches. I advised that plastic caps were available to insulate the screws ..............the middle aged hubbie then promptly used a piece of bread to fill the screw holes!. What can you say?


    Jaymack
  • 0
    Sparkingchip:

    >>>

    If you are doing testing for an EICR and you find a rewirable fuse board, a high PSC and 2.5 mm twin and earth with 1.0 mm all sorts of potential issues should be flagged up, because the earth conductor is only 0.15 mm bigger than the fuse wire.


    Andy Betteridge 


    Not quite as bad as that - the 0.85mm dia wire is not 0.85mm2 cross-section;  more like 3/4 of that (0.57mm2 to be exact) So the energy per unit length will be 57%, and the adiabatic  temperature rise (as not only is there less power, there is more volume of metal to heat ) will be 57% of 57%, or 0.32. So if the 0.85mm diameter fuse wire reaches 1100C and melts, the   CPC reaches something more like 340C and in that fraction of a second before it start to cool, it damages the surface of the PVC on either side of it. Not great, as the cable insulation will eventually fail,  but not likely to lead to the big danger of the CPC blowing open and the fuse remaining undamaged.

    Of course there is precious little margin if that 1mm cpc is nicked or strained at some point, and repeated firing of a fuse in rapid succession may blow the CPC clear eventually.


  • 0
    True, it’s cross section rather than area.


    And of course, if it is a healthy ring the CPC is doubled up.


    But you can find  the single cable of a 2.5/1.0 twin and earth socket ring circuit “spur” quite legitimately wired directly into the fuse holder protected by a 30 amp fuse wire.
  • 0
    And the Codebreaker book is only flagging it as a C3, which is hardly over the top.
  • 0
    Well, it's not that simple is it Andy? The PSCC at the socket is not the same as on the tails, it is reduced by the cable resistance. Around the ring there are two conductors in parallel so the actual Earth is 2.0mm, and the PSCC is similarly reduced. The wire in a rewirable fuse holder has very little material around it (by design) and the fusing current is significantly lower than the CPC, even if this is 1mm2. It is very rare to find the situation you describe today, and a LOWER PSCC is actually worse for CPC failure because the fusing takes much longer so the CPC gets hotter. The I2t value is the important bit, fuses get faster and faster as the current increases, unlike magnetic circuit breakers which have a minimum time to open depending on mechanical inertia which cannot be reduced whatever the current. These cables and circuits are still considered safe, and with an RCD are even safer.
  • 0
    Also consider the failure mode of an slightly undersized c.p.c. - its only going to get a bit warmer that it should (e.g. above the typically 160 degree limit) - so it's not going to vaporise the copper c.p.c. just risk melting some insulation - at worst case creating some additional L-PE faults within the T&E cable (probably at bends) - which again should be cleared by the repaired fuse blowing again (probably with further damage to the cable) - all very inconvenient certainly, costly even and certainly well below the standard set by the regs, but the risk to the safety of users of the installation isn't that great I'd suggest.


       - Andy.
  • 0
    A cable has two ends, plus a bit in the middle and can be damaged anywhere along its length, you cannot only consider the extremities of a circuit.


    There are two double sockets immediately adjacent to the consumer unit in my garage, the cable length has an absolutely negligible effect on reducing PSC with only a few inches of cable, the circuit cable (4.0/1.5 protected by a B32) is shorter than the test leads on my meter.


    Consider the worst case scenarios, not the best.
  • Former Community Member
    0 Former Community Member
    UKPN:

    What surprises me is why this guy is still on here asking questions on codes that were supposed to be remedied within 28 days ago. and the local council notified. Putting aside he has employed an amateur electrician who doesnt know a C2 from a Fi, and these "defects" didnt need modifying anyway, why hasnt the "inspector" fixed the "potentially dangerous" installation? Alternatively, why not employ a real electrician? Whats next? The forum waits.


    Regards, UKPNZap


    IMO the codes have been remedied within 28 days.

    Who would be responsible for notifying the council, the electrician issuing the certificate?


  • 0
    JPCoetzee:
    UKPN:

    What surprises me is why this guy is still on here asking questions on codes that were supposed to be remedied within 28 days ago. and the local council notified. Putting aside he has employed an amateur electrician who doesnt know a C2 from a Fi, and these "defects" didnt need modifying anyway, why hasnt the "inspector" fixed the "potentially dangerous" installation? Alternatively, why not employ a real electrician? Whats next? The forum waits.


    Regards, UKPNZap


    IMO the codes have been remedied within 28 days.

    Who would be responsible for notifying the council, the electrician issuing the certificate?




    No, it seems to be the landlord.


    UKPN makes a good point.


    I think that one has to do one of two things: (1) get it fixed by a "qualified person" who will certify in writing that the work has been done; or (2) get it fixed by anybody else and then get a new EICR which demonstrates that the installation is safe for continued service.


  • 0
    JPCoetzee:
    UKPN:

    What surprises me is why this guy is still on here asking questions on codes that were supposed to be remedied within 28 days ago. and the local council notified. Putting aside he has employed an amateur electrician who doesnt know a C2 from a Fi, and these "defects" didnt need modifying anyway, why hasnt the "inspector" fixed the "potentially dangerous" installation? Alternatively, why not employ a real electrician? Whats next? The forum waits.


    Regards, UKPNZap


    IMO the codes have been remedied within 28 days.

    Who would be responsible for notifying the council, the electrician issuing the certificate?




    Under Section 3 of The Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020, the landlord is responsible for obtaining all the required paperwork, and notifying anyone who needs to be notified.  That would be completely separate from any notification under Building Regulations, which is often done by the electrician.

    https://www.legislation.gov.uk/uksi/2020/312/regulation/3/made


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