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Ring Main at Consumer unit

Former Community Member
Former Community Member
My daughter has just had an electrical safety check done and I suspect that the electrician has been over zeleous..

Would anyone care to comment.


There is no grommet where the meter tails enter the consumer unit and the outer insulation stops just short of the knockout.

He has graded this C1.   Now my opinion is that that does not present an  an immediate threat to the safety of personell

It needs fixing but surely only a C2?


More intriguing.  He gives a C3 to the ring circuit because the two legs enter the consumer unit through separate knock outs.  I can't find that in the regs


And finally an old chestnut which has been discussed before.   A C3 because two radial "circuits" are served by a single breaker..  I have always argued that the definition of a circuit is that it is served by a single breaker.  Certainly if both radials were brought to a junction box outside the CU and then connected to the breaker by a single cable it would meet the definition of a radial..


Thanks for your attention

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  • 0
    but those wanting a C2 need to tell us why. The Tails do not lack fault protection Andy, the sheath has nothing to do with that.

    I beg to differ. Without a sheath they don't comply with 412.2.4.1 (ii) (a) and without that it's hard to see which bit of chapter 41 the arragement can be claimed to comply with.


    The regs gave up relying on basic insulation alone for shock protection at least 40 years ago - basic insulation exposed to touch is no more satisfactory than unearthed steel conduit containing 230V singles or a circuit with class I accessories but no c.p.c. - any of those would be a C2 to me.


    Certainly short exposed length are likely to be a lower risk in practice than longer ones - likewise a single unearthed appliance less of a risk than an entire circuit of many such - but the EICR codes too crude to take much account of such factors.


    To me - immediate danger (e.g. exposed conductors) - i.e. zero further faults needed for danger to occur - C1.


    Danger if one further fault occurs - C2


    Danger only if two further faults occurs would normally be acceptable (our normal double fault to danger) - but if current regs demand further protection omission of that protection would be a C3.


       - Andy.
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  • 0
    but those wanting a C2 need to tell us why. The Tails do not lack fault protection Andy, the sheath has nothing to do with that.

    I beg to differ. Without a sheath they don't comply with 412.2.4.1 (ii) (a) and without that it's hard to see which bit of chapter 41 the arragement can be claimed to comply with.


    The regs gave up relying on basic insulation alone for shock protection at least 40 years ago - basic insulation exposed to touch is no more satisfactory than unearthed steel conduit containing 230V singles or a circuit with class I accessories but no c.p.c. - any of those would be a C2 to me.


    Certainly short exposed length are likely to be a lower risk in practice than longer ones - likewise a single unearthed appliance less of a risk than an entire circuit of many such - but the EICR codes too crude to take much account of such factors.


    To me - immediate danger (e.g. exposed conductors) - i.e. zero further faults needed for danger to occur - C1.


    Danger if one further fault occurs - C2


    Danger only if two further faults occurs would normally be acceptable (our normal double fault to danger) - but if current regs demand further protection omission of that protection would be a C3.


       - Andy.
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