Extending ring main - needs cable join.

[incubus1980]

Hi,

I have a spur in my loft at the moment that feeds off of the ring main. I wish to put another socket up there and not have to worry about the load on the cable so i've run a 2.5mm cable down the trunking into the socket where the spur was connected with the intention of extending my ring into the loft.

I'm not 100% sure about the best way to join the cable. I have this: B&Q Crimp Tool Connector Kit & Ratchet, 5052931109418.

From what I have been reading people are saying you must use a ratchet crimper and the blue butt connector for the live/neutral and the red butt for the earth. I can't find any markings on this kit or the connector anywhere online. Does it seem ok to use this kit to join the solid core cable?

For info, I've made a few test joins with the kit and they are absolutely solid. I can't pull them apart. I also used heat shrink and they will be accessible for inspection as they will sit in the box behind the face plate. Mechanically it is solid but i'm worried about the integrity of the connector once it has a current load on it i.e. is it likely to melt?

Cheers,

John.

 

[Deleted member 9648]

Insulated crimps on solid cores are unreliable IMO. Use wago push in connectors.It is vital to be sure the circuit you are extending is actually a ring,this can only be done by testing.
Once you have completed the work it is also vital to test the integrity of the extended ring as breaking it may result in a serious overload on the cables. If you are unable to do this ask an electrician to do the work.

 

[HandySparks]

I'd agree that Wagos are a better option than a crimp.

If I was doing this, I'd just change to socket in the loft for a fused connection unit with 13A fuse and hang as many sockets or other accessories off that as I needed. The load on the spur would then be limited to 13A.

 

[incubus1980]

Hi,


thanks for replying. My brother in law is a qualified electrician and we changed the consumer unit a few months back so I'm sure it is a proper ring I'm extending. He suggested the extension to the ring otherwise I would have just left the spur in place but he's now away on holiday so I couldn't ask him about the crimps. He'll test whatever I've done when he gets back to make sure it's all safe.


I liked the idea of the crimps as they are small and very secure. I put some test cable together and it is solid; no way would it come apart. I like the idea of the wagos but they look bigger than the crimps and the space is limited. I'll see if I can get smaller packs of the wagos as I don't need the big packs screwfix etc sell.


What are the issues with crimps; is it the cable can come loose or that they can't take the current?


Cheers,


John

 

[HandySparks]

I liked the idea of the crimps as they are small and very secure. I put some test cable together and it is solid; no way would it come apart. I like the idea of the wagos but they look bigger than the crimps and the space is limited. I'll see if I can get smaller packs of the wagos as I don't need the big packs screwfix etc sell.


What are the issues with crimps; is it the cable can come loose or that they can't take the current?

The issue is that it's difficult to get a robust connection using the standard insulated crimps, especially on solid core cable (like T&E). The wall thickness of the crimp tube is fairly thin and it won't be a welded seam, so if the connection is disturbed, it's possible for the crimp to relax its grip on the solid core. The advantage of the Wagos is that it contains a sprung contact so, if disturbed, it will still retain contact pressure. The latest push-on Wagos are really quite small.

 

[incubus1980]

The issue is that it's difficult to get a robust connection using the standard insulated crimps, especially on solid core cable (like T&E). The wall thickness of the crimp tube is fairly thin and it won't be a welded seam, so if the connection is disturbed, it's possible for the crimp to relax its grip on the solid core. The advantage of the Wagos is that it contains a sprung contact so, if disturbed, it will still retain contact pressure. The latest push-on Wagos are really quite small.

Excellent, looks like wagos is the way to go.

thanks,

John

 

[incubus1980]

What sort of rating do I want for the wagos connector. I see the two terminal push fit are rated at 24A whereas the lever ones are 32A.

I understand that there should never really be the case where more than 24A would ever be present on the connector but if the ring was to become open is it better to fit the larger lever type or the push fit (assuming also that the cable hasn't failed too under the higher load ).

John.

 

[telectrix]

the 24A ones are adequate. and quite small.

 

[telectrix]

alternatively, line products ( forum sponsor) do in line push fit connectors. only a bit fatter than crimps. a doddle to use.

 

[incubus1980]

Thanks, i'll look into both products.

John.

 

[telectrix]

this is the line products in-line connector.