Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 28 replies
  • Subscribers 32 subscribers
  • Views 4079 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

Terminating Twin and Earth

nicemark
I have been arguing about the methods of separating out the ends of twin and earth cable.


An old accepted trade method was to simply grip the earth wire and tear it out of the insulation to split the ends open.

However this puts considerable strain on the earth wire and in the case of 1mm wire it is very easy to stretch a significant amount. 


I was wondering if you there is data or evidence to demonstrate that this method is not acceptable. 

Parents
  • 0
    Yes, Copper does work-harden quite easily when bent around to fit a socket. Getting it in the right place the second time is much more difficult because the wire is significantly stiffer. This process does not affect the cross-sectional area, although it moves dislocations and crystal boundaries about. I am surprised that any of you are thinking that the force needed with a PVC cable to extend an already present split (where you got to the CPC in the first place) is sufficient to stretch the wire, it should not be. Metals below the yield point (the force needed to stretch the wire) are elastic and will recover completely when the force is removed, exactly as a spring. If this were not the case bridges would slowly descend in a gentle curve as vehicles passed across! I suggest anyone with a micrometer or vernier caliper (digital) try this test yourself if you don't believe it.2.51.5 will never be a problem, the CPC is much stronger.
Reply
  • 0
    Yes, Copper does work-harden quite easily when bent around to fit a socket. Getting it in the right place the second time is much more difficult because the wire is significantly stiffer. This process does not affect the cross-sectional area, although it moves dislocations and crystal boundaries about. I am surprised that any of you are thinking that the force needed with a PVC cable to extend an already present split (where you got to the CPC in the first place) is sufficient to stretch the wire, it should not be. Metals below the yield point (the force needed to stretch the wire) are elastic and will recover completely when the force is removed, exactly as a spring. If this were not the case bridges would slowly descend in a gentle curve as vehicles passed across! I suggest anyone with a micrometer or vernier caliper (digital) try this test yourself if you don't believe it.2.51.5 will never be a problem, the CPC is much stronger.
Children
No Data

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines