Sanity check- crimps and extending ring main

[Exciton]

Hi Guys,

Quick sanity check if I may.

I want to extend a ring main (add 3 extra double sockets) by extending off a single socket. For a variety of reasons it is not easy to access the wiring to rerun the cable to the original socket etc.

Is it OK to extend the original 2.5mm T&E using crimps (as seems to be suggested on this forum) in the original back box and cover with a blanking plate? There is not enough room to use terminal blocks.

Are these the correct connectors?

http://www.screwfix.com/prods/70554...Accessories/Crimps/Crimp-Red-Butt-Pack-of-100

using this crimper

http://www.screwfix.com/prods/70036...rs/Crimpers/Forge-Steel-Ratchet-Crimping-Tool

and do you have to cover with heat shrink?

http://www.screwfix.com/prods/17109...ies/Cable-Covers/96pc-Heat-Shrink-Tubing-pack

Thanks

Mark[/url]

 

[rebuke]

It's OK to do that - obviously as long as you extend the ring properly (i.e. extend one leg at the existing socket to your first socket, then new cable from first to second to third, then go back from third to the other leg at the existing socket).

As for crimps, the tool is correct, but for 2.5mm cable you want the blue crimps: http://www.screwfix.com/prods/75317...ccessories/Crimps/Crimp-Blue-Butt-Pack-of-100

Heat shrink isn't required if it's behind a blank plate, only if you were doing it in the middle of a cable with no other protection.

 

[Exciton]

Thanks for the reply and heads up on the connector size!

Cheers

Mark

 

[Adam_151]

But you do want red ones for the earth, as that is only 1.5mm on 2.5mm PVC/PVC T+E, (or even 1mm for a lot of the 2.5mm installed in the late 70's... but thats another story!)

RED = 1mm & 1.5mm
BLUE = 2.5mm
YELLOW = 4mm & 6mm

So you'll need a pack of each

 

[Exciton]

Cheers! Good job I had a last check before I dashed out the door to Screwfix!

Mark

 

[ban-all-sheds]

 

[Exciton]

Thanks B-A-S!

That's why I was asking for a sanity check as the searches I ran came up with using connectors mixed views on which connectors to use! I thought I would ask the experts!

Anyway just to say the crimps worked really well and I now have an extra tool to add to my collection so not a bad day after all!

Thanks to all those on the forum for sharing their knowledge.
cheers

Mark

 

[skenk]

hope you used the blues AND reds for lives/cpc

 

[Exciton]

Yes - thanks for checking! had a few practices on some scrap and I am really impressed with the crimps - so much easier than terminal blocks. Why are they not used more routinely?

Cheers

Mark

 

[JohnD]

you can get insulated crimps with a built-in heatshrink sleeve at each end. I think they're great.

not everyone uses them as the correct ratchet crimpers are relatively expensive, especially if you get good ones, and you need practice getting a good joint. Occasionally when you tug one they come loose anyway and the crimpers can be awkward in confined spaces.

not generally a DIY tool.

 

[Exciton]

Pre-attached heatshrink sounds like a great piece of lateral thinking by someone - I agree a great idea!

Cheers
Mark