Repairing a ring main

Discussion in 'Electricians' Talk' started by jld142, May 10, 2018.

  1. jld142

    jld142 New Member

    Hello All,

    I had a friend round (who is an electrician) to help me change 6 x 1 gang plugs into 2 gang plugs.

    During the work they managed to slice through my main power ring (i think) twice in 2 different rooms!! They have connected the wires back together using red crimps and a ratchet crimping tool. Then wrapping in electrical tape. Obviously this makes me a little paranoid as to whether this is actually safe.

    My questions to you all here.. is it safe to use red crimps for the ring mains on a house? Ive been reading crimps are the most secure way to join connections but i get confused with the "current rating" against each colour of crimp. Can someone explain this to me?

    I also read that junction boxes should be used, though there appears to be man debates over crimps vs boxes..

    I am not living in my house yet so i can afford to wait and get this resolved the correct way. I ideally do not want to be rewiring the entire house. Im not one of these il just pay someone and they will fix it kind of guys. I like to know a bit about it all to give me some piece of mind that what has been done is safe and acceptable.
  2. JP.

    JP. Screwfix Select

    Jidl an electrician did not do that job.
  3. dobbie

    dobbie Well-Known Member

    There are different opinions on the use of crimps,I personally do not like to see crimps used on solid cables.

    If crimping,they should have used blue crimps on the 2.5 oversleeved with heatshrink.

    I would have used a hager/ashley j803 maintenance free junction box.

    You will probably get a lot of differing opinions.
  4. Bazza-spark

    Bazza-spark Well-Known Member

    Agreed Dobbie. Crimps are fine on stranded but very touch and go on solid. How he got 2.5 into red crimps I'm not sure.

    MF Junction box definitely the way to go.

    Kind regards
    dobbie likes this.
  5. jld142

    jld142 New Member

    Haha! He may have the qualification but I’m starting to agree with you! I’m glad I listened to my gut and confirmed. Looks like il get someone else in.
  6. jld142

    jld142 New Member

    Thank you @Bazza-spark and @dobbie. Il get another person in. Hoped to save a bit of money by using a friend.. although he is qualified the results speak louder!
  7. Bazza-spark

    Bazza-spark Well-Known Member

    @jld142 he may well be qualified. However if we stand back and look at say car mechanics. There are good ones, you go to them every time. They charge a little more, but when you get your car back it is running to perfection. Then there are those not so good. They fix your car but there is a niggle and it has to go back, maybe a couple of times.

    Look now at electricians. They work on things from the power stations, overhead lines and distribution systems, through substations and domestic, industrial, commercial systems. They also work on domestic appliances, industrial machines, at one time televisions and radios and so it goes on.

    Qualified is only a part of it. Knowing what you are doing, having pride in your work and doing the job properly are the main isssues. I was always taught the job is at it's best when the tradesperson (PC see) leaves it. It starts to deteriorate from that point. You can only be a true craftsman in so many areas of the trade.

    Hope that helps.

    Kind regards
    Josh.91, HappyHacker and KIAB like this.
  8. JP.

    JP. Screwfix Select

    I dont believe that a time served electrician would do that kind of work Bazz..come on m8 red crimps/insulating tape? - chopping the ring final twice when not necessary, this and that. Nope.
  9. jld142

    jld142 New Member

    JP, I admit, I am starting to have doubts myself. However, my question in this thread was not to question the individual but to question the methods.

    I have since arranged a new electrician to have a look and hopefully with a bit of understanding as to where to use crimps, what the differences are and what current rating means I will hopefully be able to identify safe work.
  10. Coloumb

    Coloumb Well-Known Member

    Maybe the op has it wrong, I mean how could physically get a red crimp on 2.5mm. The earth maybe...

    If the cables where chopped in the wall then even the best MF box aint gonna fix that, unless your happy to have one on your wall. The only two options then are to replace the chopped length of cable or crimp.
    Josh.91 likes this.
  11. jld142

    jld142 New Member

    Maybe I do. All I know is they cut virtical wires running along side my sockets. There was mention of ring mains and wires for the lights.. I don’t really remember too much. There was 3 wires in each line he cut and he crimped them with red crimps.

    Il try and get some pictures at the house this weekend.
  12. JP.

    JP. Screwfix Select

    See what you mean Jld..anyway whatever happens I hope you get everything sorted to your satisfaction m8, and as you are interested you will learn something from the job. ps : - myself cannot stand crimps, but that is neither here nor there as only diy myself.
  13. Josh.91

    Josh.91 Member

    Then you would be surprised how often they are used.
    Regs say a crimped cable does not need accessibility, whereas a jointed cable does.
  14. DIYDave.

    DIYDave. Well-Known Member

    DId a little ‘mates job’ a while back when a friend though easy job, change a 2G faceplate for a new one

    Trouble was cables in back box were mega short, no slack to pull and new faceplate terminals in a differant layout so don’t fit

    So I extended the ring inside the box with a single short length of 2.5 to faceplate

    Used yellow crimps and put all 3 cores in at one end then with a ratchet crimper, a good old squeeze

    Did a ‘tug test’ and all cables rock solid

    Guess like everything there’s a method and even varying qualities of crimps
  15. Coloumb

    Coloumb Well-Known Member

    Technically no crimp will ever comply with the regs due to the missing outer sheath. It doesn't matter what you use, heat shrink, insulation tape whatever, it will not be type tested and match the required BS standards of teh outer sheath used for twin and earth. For example SY cable is now NP due to it not being recognized as cable to a BS standard.
  16. Dr Bodgit

    Dr Bodgit Well-Known Member

    Just use these and jobs a good 'un :rolleyes:

  17. seneca

    seneca Screwfix Select

    As they were inside the back box you'd have been better off using block connectors, more reliable than crimps on solid cores and well whithin regs. being inside the back box.
    dobbie likes this.
  18. JP.

    JP. Screwfix Select

    Josh if you are happy with them m8 all's good - I am not saying they are rubbish, but myself have never been satisfied with crimp integrity after crimping which more then likely boils down to my crimping technique which is rubbish I would think..thank goodness for splicelines, Wagos etc etc which are excellent tbqh.
    Josh.91 and seneca like this.
  19. dobbie

    dobbie Well-Known Member

    Went to a job a few years someone had tried to crimp pyro to extend a couple of circuits buried in the trunking.
    Needless to say the crimps just about fell off.
    Bazza-spark likes this.
  20. Rulland

    Rulland Well-Known Member

    Ive 'test' crimped various cables, and I would never trust solid cores in a crimp, there just seems to be no real clamping force as the conductors don't really give.
    The solid crimped I've tested, if I move the cables a couple of times the joint basically loosens, I know I know, that the joint wouldn't, under normal conditions, be mobile, but I just, sincerely, do not trust them, just my take though people.

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