Extend Ring cabling or rewire ?

[Licklieder]

I have previously posted about splitting the ring in my flat to install additional new sockets whilst insulating the walls in my flat.

The thought has just occured to me that there there is one wall in the lounge, that if I insulate, I will need to extend the exsting wiring by say 100mm to bring it though the 60mm of insualtion to remount the sockets. Likewise in the bedrooms, there are fused outlets for the electrical heaters that will need extending by the same. The new sockets will be mounted inline with the exsting, so the actual cable run through insulation should be less than 50mm depending on the depth of back box used.

From previous posts, I understnd that crimping provides maintenance free connections. is it acceptable to extend the cabling to the two affected sockets that way or should I be looking at re-wiring the circuits to extend? The exsting ring cabling is 2.5mm single core PVC insulated in conduit on a 32A breaker and the electrical heater circuits are on 1.5mm radials from the CU on a 16A breaker.

There is the added complication, that if I understand how the cabling was originally installed in the flat, the ring included a bathroom razor power point that was sealed up behind tiling when I had the bathroom replaced (Part P electrician used here, and fully tested afterwards complete with certificate, so I'm assuming maintenance free connectors were used). If I did re-wire, the leg into & out of that hidden junction can't be replaced.

Matt

 

[333rocky333]

razor power point that was sealed up behind tiling when I had the bathroom replaced (Part P electrician used here, and fully tested afterwards complete with certificate, so I'm assuming maintenance free connectors were used). If I did re-wire, the leg into & out of that hidden junction can't be replaced.

Matt

Regardless of M/F connections or not it shouldnt be behind the tiling as its likely not now a "safe zone"
If you rewired, then that section would be best bypassed and rerouted

 

[ericmark]

All cable used an a ring final must be rated at 20A or more. When going through insulation this could mean using thicker cable to maintain the current carrying capability. Likely you are within the limits but it would depend on exactly how cables are run.

Extending a cable is not the same as extending the cores the outer sheaf also needs replacing the normal is to use shrink sleeve. Be it a crimp or western role wetted with solder clearly you can extend a cable. I would normally stager the wire joints within the joint to keep the overall diameter down to what the shrink sleeve will slide over which means a long joint. Clearly you can't bend the joint so in some cases there is no option but renew the cable.

Most important is testing. If you have not the skill or equipment to inspect and test then answer is simple don't do the job.

Assuming is always a problem. We assume electricians will follow the rules and there cables to your tiled over shaver socket have been removed but you don't know.

This is why I don't work on other peoples houses. It is so easy to see what seems to be an easy job which will not require notifying and then find something unforeseen which requires notifying.

There is no such thing as a Part P electrician. There are firms who are members of a scheme which allows them to self certify but there is no qualification required for the electrician. One electrician within the firm must have the ability to test and inspect and the firm has to have a set of reference books and test equipment to be a member of the scheme but only with sole traders are the electricians themselves vetted by the scheme provider.

It has to be that way or we we run out of electricians as no one could do an apprenticeship but it also means large firms can use semi-skilled labour and as a result mistakes can be made as with the Emma Shaw case.

So although a compliance certificate may have been issued you can't be certain it complies. With an installation certificate or minor works the electrician can put on limitations and also record deviations from the rules. I was under the impression that a compliance certificate was issued on the strength of what was written on the installation certificate just like the completion certificate when issued by the council but I have been told this is not the case and the installation certificate is not sent to the scheme provider.

So in real terms it's all down to the guy doing the work. I also remember in my early days of being sent with a set of meters to test which I did and wrote down all the readings. But as to interpreting those readings that was something else.

So in real terms Part P has done very little to help the house holder. What it did was stop commercial electricians from doing domestic work so it gave an opportunity to the semi-trained to move into the gap in the domestic market created when the commercial guys moved out. The scheme membership gave them a stamp of approval and also stopped kitchen fitters doing their own electrics. Don't get me wrong there are also a lot of very capable domestic electricians. What has really helped is the rated craftsman systems. It would seem only the useless electricians ever join rated craftsman systems so by avoiding anyone who is a member of rated craftsman systems your less likely to get a bad electrician.

 

[ban-all-sheds]

The thought has just occured to me that there there is one wall in the lounge, that if I insulate, I will need to extend the exsting wiring by say 100mm to bring it though the 60mm of insualtion to remount the sockets.

You will also have to take fastidious care to ensure that the cables and socket boxes do not compromise the VCL in any way.