Do you twist together?

DublinDilbert

Quick question to you all, when one of you are fitting say a plug socket, with 2.5 looping in and out again, do you twist the 2 ends together, to make a good mechanical contact before tightening down the screw?

Some people do, but most don't. I like the idea of making a mechanically strong contact before clamping down the screw on top of it. Having the 2 conductors side by side, it seems to easy for the screw to clamp one tightly with the other forced into the corner..

fishdog

I do! If it is just 1 I fold it over.

DublinDilbert

fishdog wrote: »

I do! If it is just 1 I fold it over.

Yea i always fold over a single also....

The GF's father asked me to add an extra plug socket yesterday, when i took the nearest socket off the wall the two earth wires just popped clean out! this wouldn't of happened if they were twisted....

DublinDilbert

God i thought this thread was going to lead to a great debate on whether to twist or not....

What to they teach people when doing the senior trades these days?

fishdog

What to they teach people when doing the senior trades these days?

To twist, I think! I was taught to anyway.

Davy

fishdog wrote: »

To twist, I think! I was taught to anyway.

Last I heard, only twist stranded.

.G.

davton wrote: »

Last I heard, only twist stranded.

I'm just out of phase 2 and thats what we were told.

Plus always double back where possible and if its solid cable and you've 2 then place them side by side so the screw bears down on both

sparkyjo

super is exactly right only stranded not solid as solid cables don't twist tightly together and once you bend them they weaken and can snap

DublinDilbert

superg wrote: »

I'm just out of phase 2 and thats what we were told.

Plus always double back where possible and if its solid cable and you've 2 then place them side by side so the screw bears down on both

Its interesting... cause quite a few times i have taken old sockets off the wall and one of the cables just pops straight out....

With an MCB connection they tend to clamp very well on what ever you put into them, but with the likes of a screw in a socket the odd time it can sometimes clamp more on one cable than the other...

Solair

It depends on the quality of the fitting. Well made switches, sockets etc have a compression plate under the screw. This works best without twisting as the two wires are held firmly in place clamped between too plates like a vice! Cheap fittings use a round tunnel and a large screw. In these you need to twist to ensure the two wires are gripped in place. The screw only comes down at one point so ideally the wire needs to be bent etc

You'll see what I mean if you compare an MK logic socket with a cheap unbranded one. It's always worth using good quality fittings, they go beyond simply complying with the minimum requirements. They're sturdier, better designed, easier to work with and wire up and most of all safer.

I think the clamping plate design should be obligitory, it's FAR safer as cables won't fall out!

fishdog

You'll see what I mean if you compare an MK logic socket with a cheap unbranded one

A big difference alright!

davelerave

ya as already said you shouldnt twist solid wires only flex or stranded as it weakens them and they can break off.the reci inspectors look to have the solid 2.5s doubled back in the sockets to fill up the connection .at least they mention it to me

10-10-20

Some medium to high powered electrical devices recommend that the contacts are re-tightened after a period of use.
I can remember cases where I know I've tightned a screw down on 2.5sq on the back of a socket, only to find it moderately loose afterwards.

And then there are the el-cheapo connector blocks from the major DIY stores which won't take the strain of being tightened at all, and you find the grub-screw coming loose having threaded itself...

What's the guidance with using connector blocks on mains cabling these days? Are they outlawed in favour of wiring small enclosures?

Solair

In general it's advisable to double the exposed cable over in the terminal. This 1. Ensures good grip and 2. Increases the contact area so should reduce RTE tendency to over heat. Personally, I find a lot of fittings can't really cope with more than one wire. Sockets really should have in and out terminals to allow for easy wiring where cables are looped through and onto the next fitting. Just ramming two and sometimes three wires in seems a little shoddy yet it's common practice.

Also 32a breakers ought to have appropriate terminals for connecting a ring circuit, rather than just single terminals. I know rings are far less commonly used in Ireland than in the Uk, but every house in the Uk had them yet there is no provision made to wire them safely ! Ie a special mcb with an extra lug for the other end of the ring !

RoundyMooney

Flex: Twist together, and double back for a single run.

Solid: Double back for single, and twist together for double (or even triple on occasion :eek).

That was the way we were taught for the senior trades, and marked accordingly in the apprentice competitions way back in the long ago.

It's a habit I've stuck with since, though I mostly deal with stuff these days that cannot be bent or twisted.

fishdog

Solid: Double back for single, and twist together for double (or even triple on occasion :eek).

That was the way we were taught for the senior trades, and marked accordingly in the apprentice competitions way back in the long ago.

That was my expericence too.

davelerave

i coulda been trained that way too, it was common enough .ive seen plenty of wires snapped off this way from twisting solid copper

RoundyMooney

davelerave wrote: »

i coulda been trained that way too, it was common enough .ive seen plenty of wires snapped off this way from twisting solid copper

You have, but I bet the copper was nicked. It may not snap on the first "bend" (when you turn it back on itself, or twist it together with another core), but it may do so when the faceplate is screwed to the wall, or even before, when unsuspecting third parties move it about, or yet again twenty years hence, when Joe Soap takes it off to paint around it or something.

The amount of folk who strip with a snips/pliers is staggering.

I have to admit to using one on occasion myself, but I always stretch the PVC to breaking point, rather than cut through it, if you get me.

fishdog

ive seen plenty of wires snapped off this way from twisting solid copper

About 10 years ago there was some T & E on the market made with low grade copper conductors that snapped if you tried to twist it together. Even tightening the terminal screws could cut through the copper. I used some of it because the price was great and had to pull it out again due to these problems! I was told afterwards that it was made somewhere in eastern Europe and was not permitted in Ireland. Other than that I have had no problems twisting together.

The amount of folk who strip with a snips/pliers is staggering.

From what I have seen most apprentices are taught this way, not in college but on site. In Ireland this often seems to be "normal".

When working abroad each job I went to they gave me a new wire stripper and insisted that I used it. On the continent there seems to be much more emphasis on the quality of connections. All stranded cables have a “bootlaces” crimped on to them.

Davy

fishdog wrote: »

From what I have seen most apprentices are taught this way, not in college but on site. In Ireland this often seems to be "normal".

When working abroad each job I went to they gave me a new wire stripper and insisted that I used it. On the continent there seems to be much more emphasis on the quality of connections. All stranded cables have a “bootlaces” crimped on to them.

The bootlaces are a much better job, when twisting the strands with the insulation still on, the proper way to twisting the strands equally.

Apprentices should be told to use a stripping tool, most of the time a pliers will be ok, but always is the chance that the copper could be nicked, or even marked can be very bad, effects it over time.

davelerave

fishdog wrote: »

About 10 years ago there was some T & E on the market made with low grade copper conductors that snapped if you tried to twist it together. Even tightening the terminal screws could cut through the copper. I used some of it because the price was great and had to pull it out again due to these problems! I was told afterwards that it was made somewhere in eastern Europe and was not permitted in Ireland. Other than that I have had no problems twisting together.



From what I have seen most apprentices are taught this way, not in college but on site. In Ireland this often seems to be "normal".

When working abroad each job I went to they gave me a new wire stripper and insisted that I used it. On the continent there seems to be much more emphasis on the quality of connections. All stranded cables have a “bootlaces” crimped on to them.

i wired 6 houses with a roll of dodgy bell wire .ill never use solid bell wire again .had to fit electronic chimes with a wired push .

fishdog

Apprentices should be told to use a stripping tool

True, but this often not the case.