twisting of copper core

[kevsterdiy]

Hi

I'm replacing a length of 2.5 cable to a socket where it has been drilled though (previous owners i will add), is there a requirement for the wires to be twisted together when terminated?

thanks.

 

[RF Lighting]

NO!!

The exact opposite infact.

Twisting the ends together weakens the copper, and just causes more work when it comes to fault finding time.

 

[GaryMo]

No requirement at all, in fact I don't like conductors twisted together.
Imagine the terminal screw putting all its pressure on one conductor due to the twist. I've seen many cases of snapped conductors due to this.
I prefer them to enter the terminal side by side and have equal pressure exerted on them.

 

[Lectrician]

No - It weakens the cable if you twist - The copper work hardens and becomes 'brittle'.

 

[kevsterdiy]

Thank you very much for your replies from the 3 of you. I hoped that's what you would say. I have tried twisting them and they broke and with the new Mk socket I'm putting on they don't fit in the terminal location (it has a spur off the ring socket) even if twisted tight - and as you point out to test/fault find later causes a headache. What threw me is every other socket in the house (1974) has twisted wires.

 

[kevsterdiy]

I prefer them to enter the terminal side by side and have equal pressure exerted on them.

Would this till be the case with 3 as said in my above reply, for a spur as three won't sit side by side, one will have to go on top?

 

[RF Lighting]

Yep keep them all straight.

I think the twisting of conductor ends dates back to when stranded imperial cables were used.

Old habits die hard.

 

[kevsterdiy]

Yep keep them all straight.

I think the twisting of conductor ends dates back to when stranded imperial cables were used.

Old habits die hard.

Cheers RF

 

[Dippy]

"Mr. Twisty" installed the original electrics in my house. It has been a PIA making changes, or even doing the PI. In some cases I found about 10cm of cpc twisted together!

It's a long time since I studied materials physics, however IIRC "work hardening" initially strengthens the metal due to removal of grain boundaries. I believe it only becomes brittle after repeated damage.

 

[mattylad]

Oh dear!
Me decides not to do the twist again.