cpc sleeving

Discussion in 'Electricians' Talk' started by Removed 8, Jan 28, 2011.

  1. Removed 8

    Removed 8 New Member

    OK: own up, those of you who use a single length of g/y sleeving for both cpc's in a standard socket on a ring final and similar accessories.........

    Then I'll tell you why you shouldn't do so.

    Lu.x
     
  2. wally

    wally Screwfix Select

    It would make fault finding or testing that much more difficult
     
  3. Removed 8

    Removed 8 New Member

    That's true Wally, and indirectly almost the correct answer - but certainly worthy of an helpful answer award.....

    I trust that you won't mistake me from my impersonators again - even at your frail age?


    Lu.x
     
  4. Lokkars Daisy

    Lokkars Daisy New Member

    It would make fault finding slightly more difficult,,,however I always twist the 4 turns on the cpc and then sleve,,, so **** of ,,, have a cup of tea ,y
     
  5. Removed 8

    Removed 8 New Member

    Not such an helpful answer, Dais sir.

    Come along the rest of you: Do you fit a common sleeving, or use individual sleeving? Don't be shy!

    Lu.x
     
  6. unphased

    unphased Screwfix Select

    I hate finding twisted cpcs sleeved singly. Old rewireable fuseboards are the worst. The oldies who used to do this clearly never tested anything. A moot point on the NAPIT forum where I upset loads of people daring to suggest nobody bothered testing anything until Part P came along and forced the issue. Now its all "five day wonder" backlash! I detest the practice. One of the less obvious reasons is the strain on the conductors at the ends of the sleeving causing it to split and the sleeve cannot fit the full length of the wires if paired.
     
  7. gripster

    gripster New Member

    i agree totally it makes fault finding a nightmare u unsleeve the conductors try and untwist em and one of barstewards breaks leaving it short so u now have to crimp a piece on i replaced 26 sockets today and every one bar a couple of spurs were twisted
     
  8. Removed 8

    Removed 8 New Member

    Not bad, Roy. Your reply is relevant of course. But you're wrong to say that the old timers didn't test properly. The same proportion then. as now, carried out the required testing of the 'Regs' of the time. Moreover, there hasn't always been a requirement for sleeving of cpc's.

    I know this, as I'm an old stager myself and I knew what my contemporaries were doing - or not.........


    Lucia x
     
  9. unphased

    unphased Screwfix Select

    The one time I tend to use single sleeve on a cpc is when terminating a loop in to a downlight connector block where the small block size makes it fiddly to slide the cpcs in. Whats the answer then Lucia?
     
  10. Removed 8

    Removed 8 New Member

    Most replies have been correct. thus far , Roy, but there's still one important reason missing - but not enough members have responded yet for me to spout the "correct answer". I'd like to hear a few more opinions (before I get banned from the forum, again).


    Lucia x
     
  11. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Is it coz you wouldn't know if one (or more) were broken and thus relying on a single strand/core for multple protections ?


    Mr. HandyAndy - Really
     
  12. Removed 8

    Removed 8 New Member

    Good God, Andy. You're almost there!

    Lucia.
     
  13. Stan3333

    Stan3333 New Member

    Miss Miss Miss can I have a go Miss!

    Is it cos you're supposed to connect each leg to  a separate terminal in the socket (where 2 are provided) & so testing proves the integrity of the socket's earth. -ish.
     
  14. spinlondon

    spinlondon Screwfix Select

    I prefer to sleeve individually due to a number of reasons.
    Firstly I tend to wire metal back boxes with one CPC to the box, the other to the acceeory with a fly lead between. This makes using one sleeve impossible
    Secondly there is the difficulties associated with I&T and fault finding.
    Finally there is the the fact that twisting the two conductors deforms the structure which can adversly effect the conductivity, and also weaken the conductor so that premature failure is likely.
     
  15. seneca

    seneca Screwfix Select

    I sometimes use a common sleeve in ceiling roses where space is a bit limited but I can't see any reason to do it in socket back-boxes. Also, even if using a common sleeve, I don't see why people twist the conductors together,  just slide the sleeving over the wires, no need to twist them at all as that's what makes it a pita when testing.
     
  16. unphased

    unphased Screwfix Select

    No, stan, you are not supposed to do that. The separate earth lugs on a socket are for compliance with Regualtion 543.7.1.4 whereby two protective cpcs are in use and high earth currents are exceeded. Then the cpc is required to be independently connected at each accessory. In a ring circuit the cpcs are usually connected to the same cpc terminal, even when there are two available. Only exception is to comply with above reg.
     
  17. Removed 8

    Removed 8 New Member

    'spinlondon': I don't approve of your practice of taking one cpc to the back box terminal and the other to the socket terminal with a flylead between the two. You're not the only one, of course, to do it that way. But it isn't the proper way to do it.  If you must provide a flylead to the box (unnecessary in most cases) then it should be a separate short length of g/y from the socket to the box with both cpc's of the ring circuit together in the socket earth terminal.

    This question has been 'almost'  answered by 'Hands'. But it remains unanswered fully, thus far.........

    It isn't a 'trick question'. It's a matter of fundamental termination procedures.


    Lucia x
     
  18. seneca

    seneca Screwfix Select

    I think spinlondon's practice of relying on the back-box flylead to complete the  cpc continuity is very poor practice, if you have the two conductors there put them in the same termination, why rely on another possible source of problems, ie loose connection, some of those back-box earthing terminals are not great.
     
  19. unphased

    unphased Screwfix Select

    Rewording Handy's reply should settle it then. ;)

    Every conductor should be terminated individually in to a connection terminal such that each can be independently verified as being properly and securely connected. This cannot be easily verified if two separate conductors are sleeved together and terminated in the same terminal.

    Five points in the bag!
     
  20. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Is it then, coz you wouldn't know if one was broken(or relying on just touching the other), thus part of the ring could be 'not earthed' ?


    Mr. HandyAndy - Really
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice