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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



Parents
  • 0
    Regards the size of the CPC in older 2.5 mm twin and earth being 1.0 mm, it doesn’t take much to figure out that the potential issue is the size of the fault current.


    So if it TNCS and it looks like there will be a big bang with several thousand amps flowing it’s more of an issue than if it’s TT with a low current of just a few amps.


    So there isn’t a set code, it depends on the installation. I have tested sockets in people’s homes by substations with fault currents in excess of 3000 amps and the installations have TT earthing whilst houses further away are TNCS earthed, which I have been told was because the DNO didn’t want any big bang earth faults to occur in these installations.


    One such TT installation was within forty feet of the substation transformer and I was actually struggling to get an acceptable Ra on the earth rod I was installing whilst the L/N PSC was massive, I was actually on the point of contacting the DNO to ask if the Tx actually had a decent earth, I had planned to install an upfront 100 mA RCD but couldn’t get the Ra down enough.


    Am I going to go a calculation every time? I don’t think so!


Reply
  • 0
    Regards the size of the CPC in older 2.5 mm twin and earth being 1.0 mm, it doesn’t take much to figure out that the potential issue is the size of the fault current.


    So if it TNCS and it looks like there will be a big bang with several thousand amps flowing it’s more of an issue than if it’s TT with a low current of just a few amps.


    So there isn’t a set code, it depends on the installation. I have tested sockets in people’s homes by substations with fault currents in excess of 3000 amps and the installations have TT earthing whilst houses further away are TNCS earthed, which I have been told was because the DNO didn’t want any big bang earth faults to occur in these installations.


    One such TT installation was within forty feet of the substation transformer and I was actually struggling to get an acceptable Ra on the earth rod I was installing whilst the L/N PSC was massive, I was actually on the point of contacting the DNO to ask if the Tx actually had a decent earth, I had planned to install an upfront 100 mA RCD but couldn’t get the Ra down enough.


    Am I going to go a calculation every time? I don’t think so!


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