Joining 6mm cable

[scottmeister71]

Is it safe to join two lengths of 6mm cable to avoid having to start new wiring from the CU (it currently goes to one position and I need to move it but the existing cable isn't long enough). What is the best method of joining the cable?

 

[andy]

Is it safe to join two lengths of 6mm cable to avoid having to start new wiring from the CU (it currently goes to one position and I need to move it but the existing cable isn't long enough). What is the best method of joining the cable?

crimp

 

[scottmeister71]

Could I use a cooker connection unit which I have spare. It's like this one http://www.screwfix.com/app/sfd/cat/pro.jsp?id=47806&ts=98614

 

[andy]

Could I use a cooker connection unit which I have spare. It's like this one http://www.screwfix.com/app/sfd/cat/pro.jsp?id=47806&ts=98614[/QUOTE]

providing its left somewhere accessable

 

[scottmeister71]

To sum up:
I am running cable to the first cooker control unit (no. 1) then onto a double oven. I'm then running a cable from the first cooker control unit (still no.1) to a second cooker control unit (no.2) because the distance is about 7 metres. From no.2 to the ceramic hob. But to start this run I'm using cable that used to go to an outlet plate powering a previous oven but the first cooker control unit is a bit beyond reach so rather than start from the consumer unit I was going to join my new cable from the outlet plate (accessible).
So, before it gets to CCU no.1 it goes from consumer unit to a cooker outlet plate (being used as a junction box effectively) then to CCU no.1, then as previously described.

Sorry for war and peace but I just want to be sure it's okay.

 

[mapj1]

Its OK, but watch the total current ratings - and make sure the existing cable and fuse/MCB are up to the combined load too.
Also note 60A jpoint boxes exist, but are very big.
You will need a deep back box to get 2 cooker cables in neatly.

 

[scottmeister71]

Its OK, but watch the total current ratings - and make sure the existing cable and fuse/MCB are up to the combined load too.
Also note 60A jpoint boxes exist, but are very big.
You will need a deep back box to get 2 cooker cables in neatly.

The total combined rating is 10.8kw and I intend to run using 6mm cable and a 40a mcb. Is this okay because the 'Which Book of Wiring & Lighting' seems to suggest it is unless it is out of date but I only bought this a month ago.

 

[mapj1]

It is perfectly OK, so long as the 6mm cable can cool itself, i.e. isn't run through thermal insulation or similar, and isn't so long (20m?) that voltage drop will trouble you
If it is then next size up is 10mm...

 

[scottmeister71]

It is perfectly OK, so long as the 6mm cable can cool itself, i.e. isn't run through thermal insulation or similar, and isn't so long (20m?) that voltage drop will trouble you
If it is then next size up is 10mm...

Thanks Mapj1. Most of the run is on the open loft and what is in the walls I intend to put in the oval conduit which will then be buried.

 

[mapj1]

use one size larger tube than you expect, it makes threading easier....

 

[scottmeister71]

To sum up:
I am running cable to the first cooker control unit (no. 1) then onto a double oven. I'm then running a cable from the first cooker control unit (still no.1) to a second cooker control unit (no.2) because the distance is about 7 metres. Another cable will then go from no.2 to a ceramic hob.

I am now completing the wiring and find that it is a struggle to fit 3 cables in the cooker control unit. I don't mean 3 cables in the back box but just taking the live for example, I have to put two into the 'feed' and one into 'load'. Is it normal for it to be such a tight squeeze? I have managed to get them in but is it safe. I've done what the wiring manual told me to do in terms of cable run but is it just the brand of CCU I've used which is why it's so tight?

 

[fido]

These terminals are designed to take one 10mm conductor, unlike 13 amp sockets which are typically required to take three 2.5 mm conductors (ring main + a spur). If you have managed to get two 6mm conductors in it should be safe enough, the alternative being to fit a junction box before the first cooker switch.