Connect with us

Help:Locating break in electric cable

Discussion in 'General Electronics Discussion' started by boblalux, Feb 5, 2017.

Scroll to continue with content
  1. boblalux

    boblalux

    20
    0
    Aug 15, 2016
    I am often called upon to help people with, for example, a vacuum cleaner which no longer works. First thing I do, I check continuity of the live and neutral wires between the plug and the machine. Most of the problems are just of a continuity nature along the 10-20 foot cable, but where? , Not always at the ends. Just cutting in the middle, and checking both ends for continuity, is pretty destructive. Until now, I use a pin to pierce the wire covering and measure for continuity, and test the continuity until I find it, therefore not having to cut the cable unnecessarily. Works fine, but I don't like the fact that there are now a number of tiny holes in the wire covering. Is there any better method? I tried using a compass to see if there is only a swing in the live portion of the wire, butdoesn' seem to work.
    HELP
     
  2. Chemelec

    Chemelec

    291
    47
    Jul 12, 2016
    Repairs at each end is Ok.
    But since it is Not really Practical to SPLICE a cable somewhere in the middle, Why not Just Replace it.
    And Probably the SAFEST WAY.
     
    davenn and boblalux like this.
  3. Alec_t

    Alec_t

    2,909
    791
    Jul 7, 2015
    Personally, I'd cut off about 10-20 cm from each end and test the remainder for continuity. If no continuity then I'd scrap the cable, on the basis that the wires have probably been stressed so may not be safe to use (through work-hardening, embrittlement, partial fracture).
    Even if you could locate a break part way along the cable the only fix would be to use a cable connector. That in itself would not be ideal, because it could snag on obstructions when the appliance is in use.
     
    boblalux likes this.
  4. KTW

    KTW

    273
    15
    Feb 22, 2015
    Search for opens tester.
     
  5. duke37

    duke37

    5,364
    769
    Jan 9, 2011
    Give each wire at both ends a yank and if the copper is broken near the end, the insulation will stretch.
    Look for any twists in the cable. Make sure that no twists are made when the cable is used, I use two supports with the cable wound in a figure of eight around them.
    I have made an oscillator using a CMOS 4093, set to run in the medium wave. I have used this with a small portable radio to find a junction box under the floor, the location of a cable running underground from a shed and breaks in christmas tree lights.
     
    bushtech likes this.
  6. boblalux

    boblalux

    20
    0
    Aug 15, 2016
    Good idea, I'll try this. Only problem is that on a number of occasions, it is only one of the 2 wires (live or neutral) which is broken
     
  7. duke37

    duke37

    5,364
    769
    Jan 9, 2011
    If one wire is broken, then the others are near failure. Cut off a considerable amount to get to a good part.

    The main problem is that the earth wire could be broken or near broken without any indication.

    Teach the operator to treat cables with care. Bend as lttle as possible and use a large radius.
     
  8. boblalux

    boblalux

    20
    0
    Aug 15, 2016

    Good idea. But try and teach your nearest and dearest, not to yank the vacuum cleaner cable but rather the plug, when finished (by the way, I as husband, also use it).
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-