CRIMPS

[Belboz]

I've read a fair bit on here about crimps as opposed to connector block for joining cable.

I read somewhere that crimps could not be used for joining solid core cables but this is clearly wrong from what many of the professionals have written on this site.

If I needed to join two cables, say 2.5mm, can this be done using crimps and a proper ratchet crimping tool?

If so, are the butt crimps best for this?

Also, once the crimping is done, does it need additional heat shrink over the connection to ensure proper insulation even if using insulated crimps??

Thanks

 

[comms]

If I needed to join two cables, say 2.5mm, can this be done using crimps and a proper ratchet crimping tool?

Yes make sure you do use the ratchet type crimp tool.

If so, are the butt crimps best for this?

Yes use blue for the line & neutral (live / neutral) & a red one for the cpc (earth).

Also, once the crimping is done, does it need additional heat shrink over the connection to ensure proper insulation even if using insulated crimps??

Yes its a good idea to cover with heatshrink to comply with double insulation of the line & neutral conductors. unless the crimp is inside an enclosure of course.

 

[holmslaw]

..

 

[plugwash]

there is also the possibility of soldered joints.

 

[GaryMo]

Yes its a good idea to cover with heatshrink to comply with double insulation of the line & neutral conductors. unless the crimp is inside an enclosure of course.

Technically speaking, the outer sheath of a twin and earth cable isn't there for insulation and isn't rated as such. It's more of a protective layer.

 

[plugwash]

Technically speaking, the outer sheath of a twin and earth cable isn't there for insulation and isn't rated as such. It's more of a protective layer.

hmm, I always thought the principle was to have two layers of insulation so if one (usually the outer) got damaged in any way live parts would not be exposed.

 

[GaryMo]

hmm, I always thought the principle was to have two layers of insulation so if one (usually the outer) got damaged in any way live parts would not be exposed.

Yes, the outer protective sheath to prevent light mechanical damage. It's not for insulation purposes though otherwise t&e would be classed as double insulated.

 

[Belboz]

Thanks for all the replies.

It is not practical to replace the cables.

Reason I am asking is that, on purchasing the house, I decide to change the sockets and switch plates [ the old ones were basic white plastic] I also checked each socket with a socket tester [yes I know they are probably rubbish and a sparky would have done 'proper' testing'] and all seemed 'fine'. I replaced the sockets and switch plates ensuring that there was no bare wire showing and that all the earth wires were sleeved and correctly cross connected to the boxes and plates/sockets.

However, on two or three of them [clearly where the previous occupier had fitted them] the 2.5mm cables were connected with connector blocks. These are easily accessible behind the sockets/plates and I tightened then all up.

I am now worried, having read much on here, that this is not a safe way to have it. The two or three are feeding FCUs with 3A fuses. The connector blocks appear to be the standard 30A type. The boxes are deep.

Hence why I asked about crimping. The FCU 'extension' cables are buried behind tiles and not in conduit.

After all your replies, I am thinking that crimping may not be a better way. Any views [apart from rip the whole lot out where necessary and do it with accessible junction boxes]

Thanks