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OT Spraky Ring Main Question
ash_hammond - 5/6/17 at 07:21 AM

Guys. I've managed catch a ring main cable in the house while putting up a cabinet. Clearly my 3 in 1 detector is rubbish.

The broken cable run into the space above the garage so I can get access to it to replace it with only one joint.

Is it 'legal' to join ring cables with a junction box?
If so which type?
Ive read that it is possible to use crimp connectors and then resheve it, i dont like this idea.

Or is it best practice to replace the enitre run to the next socket?

Thanks


cliftyhanger - 5/6/17 at 07:29 AM

Not a qualified sparky, but I can't see how a JB is different to putting a socket in a ring, so should not be an issue.

However, I prefer wago connectors, but they must be in a box. Very reliable, and really useful when you need to connect several wires (had 7 in a JB in my house, try getting that lot in a JB!)


knight19770 - 5/6/17 at 07:37 AM

Hi, It's okay to use a suitable junction box as long as it's in an accessible place. You should be okay as you are putting it in the loft which can be accessed if any future problems. Make sure its rated okay for the socket circuit.

Mike


SJ - 5/6/17 at 08:11 AM

quote:


However, I prefer wago connectors, but they must be in a box.



What he said - Wago connectors are really good. After any work you should test the circuit even if just for continuity on a ring main things will still work even with a break in the ring.


ash_hammond - 5/6/17 at 08:27 AM

I've got one of these testers and I rent a property. Which I use when doing an inspection for peace of mind. It tests correct wiring and earth loop impedance.Link

[Edited on 5/6/17 by ash_hammond]


SJ - 5/6/17 at 08:47 AM

quote:

I've got one of these testers and I rent a property. Which I use when doing an inspection for peace of mind. It tests correct wiring and earth loop impedance.Link

[Edited on 5/6/17 by ash_hammond]



They are good but won't pick up if you make a bad connection when jointing the ring main.


lsdweb - 5/6/17 at 10:01 AM

Wago connectors and a wago box would be my choice.

http://www.screwfix.com/c/electrical-lighting/cable-accessories/cat7230015?brand=wago&cm_sp=managedredirect-_-electrical-_-wagoconnectors

Not sure if you can buy them in small quantities - if you can wait a few days I'll post you some.

Wyn

[Edited on 5/6/17 by lsdweb]


ash_hammond - 5/6/17 at 07:32 PM

quote:
Originally posted by lsdweb
Wago connectors and a wago box would be my choice.

http://www.screwfix.com/c/electrical-lighting/cable-accessories/cat7230015?brand=wago&cm_sp=managedredirect-_-electrical-_-wagoconnectors

Not sure if you can buy them in small quantities - if you can wait a few days I'll post you some.

Wyn

[Edited on 5/6/17 by lsdweb] [/quote

Wyn, that's a really great offer and thanks. If you want any pennies for them please let me know.


hearbear - 5/6/17 at 11:00 PM

Sons a spark and they use the blue straight crimp connectors and put that in a box. They never us the chocolate block connectors as they work loose over time, wago he is just not a fan of them for ring mains the crimp gives the best mechanical connection but best option always replace the damaged cable if possible.


ash_hammond - 6/6/17 at 10:22 AM

quote:
Originally posted by hearbear
Sons a spark and they use the blue straight crimp connectors and put that in a box. They never us the chocolate block connectors as they work loose over time, wago he is just not a fan of them for ring mains the crimp gives the best mechanical connection but best option always replace the damaged cable if possible.


I totally agree about replacing the damaged cable. The cable runs up the wall and into the loft space where I can get reasonable access. My plan is to chase the cable out of the wall and make a joint in the loft space. As it then vanishes into what I believe is into the kitchen. To find it from there would mean ripping the kitchen to bits In the next 5 years we will be replacing the kitchen, so an entire run could be replaced then.

When your son says blue crimp connectors, does he have a brand or type? I'm struggling to find a rating for these blue connectors. I know the entire ring is rated for 32amps based on two 2.5mm cable supplying any one .

I'm wanting to know what any single point of a ring must support. Wickes cable is 2.5mm and rated to 23amps where Screwfix's 2.5mm and rated 27amps! Surly a 2.5mm conductor must support the same... copper is copper. The reason being the connector for joining the wire needs to support the same amount of amps or more.

Thanks
Ash


knight19770 - 6/6/17 at 10:29 AM

My sparkies use a junction box like the screwfix (5866D) 30A 3 terminal junction box. It is a little bigger , but if it's in your loft this wont be a problem and makes it easier to terminate the 2.5mm cables in.

Mike