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second opinion

Discussion in 'Electrics UK' started by elrobbo82, 24 Nov 2011.

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  1. elrobbo82

    elrobbo82

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    just trying to get some input off a few more people. i called round to a property yesterday to replace a faulty socket. when i went to isolate the circuit i found that the down stairs sockets were on 2 2.5mm 16A radials. i noticed that the kitchen and all the appliances were supplied via 1 radial and the living room was supplied via the other. i spoke to the customer about the loading on the kitchen radial and he told me that the sockets use to be on a ring. apparently an electrician (who used to work at my work) had called round a couple of years ago and found a fault on the ring. instead of renewing the damaged cable this sparky decided to disconnect the cable and turn into two radials. i know that this is safe but i am unimpressed with the possible load on the kitchen radial (2.5mm 16A 60898) as 2 appliances could overload the circuit. spoke to one of the lads at work who told me this is ok and to just leave it. i spoke to my boss and we decided that i will come back and renew the damaged cable and turn back into a 2.5mm 32A ring.

    so just wondering what other peoples take in this situation would be. i.e break a ring that was designed and installed by some one else with regards to load and turn into radials. or replace damaged cable and keep the ring as designed?
     
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  3. Lectrician

    Lectrician

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    2 x 20amp MCB's would be the usual way.

    Did the customer have problems with tripping? If not, I do not particularly see a major problem...

    Whats the worst thats going to happen?
     
  4. elrobbo82

    elrobbo82

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    as said i know its safe but putting a kitchen with all appliances on a 16A radial in my eyes is poor design. also no installation certs were issued in regards to installing 2 new radial circuits from the cu.
     
  5. RMS

    RMS

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    Are you suggesting that the two radials were not designed before being put into service?

    Have you confirmed that an installation certificate was completed for the new circuits?

    Has the customer experienced any problems with the circuits since?
     
  6. JohnW2

    JohnW2

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    Having the entire ground floor, including the kitchen, on one 32A ring final would not exactly be the best of design practices, either! Anyway, as has already been asked, why 16A, rather than 20A radials? - is the cable deeply buried in insulation, or what?

    Kind Regards, John.
     
  7. elrobbo82

    elrobbo82

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    I am suggesting that the radial in the kitchen was not designed in regards to the loading of the appliances. If it was designed then it was poorly designed.

    There were no installation certs issued for the new radials.

    The kitchen radial does trip and the customer has reset it numerous times when using a few appliances. The radial in the living room has not tripped as the total load is quite low.
     
  8. elrobbo82

    elrobbo82

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    Not what i can see just buried in plaster. Probably just had 16A's to hand would be my guess.
     
  9. RMS

    RMS

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    Okay, what do you propose the design current to be then?
     
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  11. elrobbo82

    elrobbo82

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    i would like to see a 4mm radial protected via a 32A mcb ideally for the appliances in this particular property. 2.5mm 20A would be ideal for the living room as it has a low load demand. but as a ring had already been installed i would prefer to reinstate the ring and do away with the radials.
     
  12. RF Lighting

    RF Lighting

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    Not much work on at the moment then?
     
  13. janner10

    janner10

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    Sounds like your trying to find a problem that doesn't exist.
     
  14. securespark

    securespark

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    I have some customers who will not pay to have repair work done, so often have to make a RF circuit into one (or two) radials, if a leg goes down.

    I will use 20A breakers and hope that the area served is <50m².

    If not, I note it as a departure on the cert.
     
  15. elrobbo82

    elrobbo82

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    could change the breaker for 20A and see how that goes but as the sockets are not far apart i would prefer to reinstate the ring. customer is happy with surface mounted pvc trunking so not much damage in renewing.
     
  16. JohnW2

    JohnW2

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    So why don't you upgrade at least the kitchen one to 20A then (once you've confirmed that the installation method is OK for that)?

    Kind Regards, John.
     
  17. JohnW2

    JohnW2

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    The 50m² thing is only a 'rule of thumb' referred to in the past tense in an 'Informative' Appendix of the regs - does 'contravening' that really count as a 'deviation'? ... and as of 1st January, it won't even be a 'rule of thumb' :)

    Kind Regards, John.
     
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