Crimping 2.5mm twin and earth

[Jon Fox]

I am planning to move a double socket in our utility room, and to do so i will plan on extending the two 2.5mm twin & earth cables that run to it (it's on a ring main and the existing cables are buried in the wall). I plan on crimping extra lengths of 2.5mm twin & earth onto the ends of the existing cables. I've decided on crimping rather than junction boxes because the regs state that inaccessible buried joins (which this will be once plastered over) should be soldered or joined "mechanically". What i want to check is if this is the correct connector to use:

that is already insulated, i was also thinking of using some heat-shrink sleeving - can anybody tell me which out of these is the right one to use for 2.5mm twin and earth please?

in advance, Jon.

[BigWallop]

> Thanks in advance, Jon.

Why not leave the existing socket where it is and tap a spur off it to the new socket position with a single 2.5mm csa' cable. Lot's simpler.

[Mike Harrison]

shown on the above page) to get a reliable join with these - the cheap 'plier' types (DR210) will not make a reliable joint.

[Jon Fox]

Sorry, i forgot to mention that a sink is being installed directly under the existing socket, hence it's removal (SWMBO would not be happy with a blanking plate!).

Cheers, Jon.

[John Stumbles]

wrap the whole cable around the join with self-amalgamating tape.

-- John Stumbles

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-+ The most dangerous component in a car is the nut that holds the steering wheel

[Jon Fox]

Thanks a lot for the advice. I have been wondering about that because i do have a cheapy plier type (for some car work i once did), but for mains work that's going to buried in the wall for years i thought the ratchet jobbies would be safer! I'll be ordering a pair (couldn't find them in B&Q, Homebase, Focus or Wickes tonight!).

Cheers, Jon.

[James Hart]

Mystical places DIY stores, I called in one tonight to pick up a draught excluder, could I heck as find one anywhere so I skulked off into the dark corner by the warehouse entrance and asked one of the staff. "Did you look in the plumbing section?" was his answer, oddly enough I hadn't but that's where they are. Stupid me for thinking they'd be with the door furniture.

[John Stumbles]

A few months ago our (Reading) B&Q had a kit of ratchet crimp tool + a selection of crimps in an assorter-type box for soemthing like £20. IIRC it was shortly after I'd bought a tool from CPC (which doesn't fit in the assorter box I keep my crimps in :-()

-- John Stumbles

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-+ Pessimists are never disappointed

[John]

DHCR15 shown on the above

will not make a reliable

Interesting point - got a DV DHCR15 for crimping the LV cables on some halogen lights and it made a fine job. Needs a fair bit of muscle, though. Not sure I'd really be happy crimping extensions onto a ring cct and burying in plasterwork - but it's more of a gut feel than engineering consideration. Is that crimp butt connector designed for multi-strand or single conductor, I wonder?

[Chris Oates]

consideration.

I've never seen red/blue/yellow insulated crimps used on solid wire with a ratchet crimper but I'm not aware of any prohibition bare barrel crimps are however extremely common in underground jointing but the crimper, by it's size, is enough to convince you that the joint will be permanent (plus it's usually strain relieved with epoxy)

For perspective think of all the countries that allow the use of wire nuts

[David Hearn]

I saw something similar in our local B&Q (Guildford) - however when I looked closely, it said something like "for automobile use only"...

D

[BigWallop]

Then you should still try and keep your connections inside a box of some sort (a single surface box with a blanking plate), and place the whole thing inside the wall cavity. You can still take a single PVC to the new socket position from the two ring cables inside the box. This is a lot safer than leaving open connections lying about inside the wall.

[dmc]

I think I've asked this before but....

Is there a difference in the crimps used on cars and the crimps used for mains wiring? I ask because my dad was a mechanic until a couple of years ago and has stacks of crimps and a whole range of snap-on crimpers (all rachet type) that he used on cars - are these suitable for mains? (I guess so assuming they are the correct size...)

Darren

[Chippy]

Though we have them lying around, I've never used crimp connectors.

A couple of questions:

Does one use the same connector for the smaller diameter earth conductor in T&E?

I notice that the conductors of 2.5mm T&E will fit into red connectors, designed for 1.5mm. Is there any good reason not to use this combination?

[Jon Fox]

Thanks. I'm not sure that would be correct as far as the regulations are concerned though. As i mentioned, they state that innaccessible joins must be soldered or mechanical, which rules out junction boxes. What you suggest is effectively a junction box :(

Cheers, Jon.

[BigWallop]

NO. Place the crimped terminals inside a suitable box to protect them as much as possible, is what I meant.

[Jon Fox]

Oh i see, thanks.

Jon.

[Andrew Gabriel]

Actually, one option is to use a junction box with screw terminals as normal, and then to solder the connections to the terminals too. Only do this if you are already skilled at soldering though. If you are unskilled at both soldering and crimping, I would suggest you use crimps with a good ratchet crimper which is more likely to give a good join in unskilled hands.

[Dave Plowman]

If they're the red yellow and blue sort, I don't think so, but they do tend to vary in apparent quality between makes.

FWIW, I think they look the pants in car wiring, since proper terminals are available.