Double back & Twisting wires - Best Practice

Post Reply
GLion
Posts: 6
Joined: Mon Jul 19, 2021 9:54 am
Answers: 0
Has thanked: 2 times
Been thanked: 0

Double back & Twisting wires - Best Practice

Post by GLion »

What is the current best practice when it comes to terminating wires, I'll break it down a bit.

- 1 x wire into round terminal with screw

- 1 x wire into clamp terminal (MCB, Iconic sockets etc)

- 2+ x wire into round terminal with screw

- 2+ x wire into clamp terminal (MCB, Iconic sockets etc)


What I've been doing:
- 1x wire into round terminal with screw.
1mm always double back, multi-strand twist strands up tight & double back up to 2.5mm if it will fit. Always twist up multi-strand wires tight.

- 1x wire into clamp terminal (MCB, Iconic sockets etc)
same as above (although I've heard its best not to twist the strands up tight)

- 2+ x wire into round terminal with screw.
Twist wires together only.

- 2+ x wire into clamp terminal (MCB, Iconic sockets etc)
same as above (although I've heard its best no to twist and just have cables next to each other)

I've heard twisting up strands tight is bad practice as the copper work hardens and can become brittle. Also twisting multiple wires together makes it difficult to add another wire in the future or separate if needed.

Thoughts?
JamieP
Posts: 478
Joined: Tue Apr 14, 2020 11:08 am
Answers: 0
Has thanked: 92 times
Been thanked: 18 times

Re: Double back & Twisting wires - Best Practice

Post by JamieP »

If we are talking about your usual stranded conductors

I personally don't twist anything in clamp terminals, such as MCBs etcetc

For screw terminals I twist and if possible to fill the gap nicely will fold as well otherwise just twisted
Satobsat
Posts: 24
Joined: Thu Jul 01, 2021 4:49 pm
Answers: 0
Has thanked: 6 times
Been thanked: 2 times

Re: Double back & Twisting wires - Best Practice

Post by Satobsat »

With single strand I twist for screwed terminals and allow the twist to extend back up the cable so the insulation is also slightly twisted 10-15mm. I find it gives the cable a bit more support and prevents breakage.
For clamped terminals I twist single cores together if there are more than two as sometimes the clamp doesn't grip the third cable if they are just doubled back.
For stranded 1.5 to 16 I twist for screwed terminals always.
For stranded 1.5 to 16 clamped it depends on the situation.
Earths are always twisted together. That way if it ever does come loose at a socket or light it will not affect those further out on the circuit.
Post Reply