Extending electric cable

[masscrazy]

Hello,

I am in the process of changing a light switch to the other side of the door.

So far the architrave has been taken off and the plaster has been chiselled out so a new length of cable can go around door to a new light switch box. The cable is 3 core electrical cable.

I have bought this and simply plan to put the current cable into one end the new length of cable in the other and run it around the door into the new light switch box.

Is this ok to do?

 

[EFLImpudence]

Not with one of those.
Nor can you 'run around the door'.

You will have to go under the floorboards above and reroute the cable so it has a straight drop to the new position.

You need one of these which are allowed to be hidden under the floor boards.

 

[Johnmelad]

Windup...

 

[PrenticeBoyofDerry]

You need to follow the permitted safe routes for cables (floors and walls)
Can be found here:
//www.diynot.com/wiki/Electrics:Installation-Techniques

Also when joints are made they cannot be buried or hidden within the fabric or voids of the building without being the type of joint that is considered maintenance free and a simple connector is not considered that.
You may also now need to have 30mA RCD protection on any newly installed buried cable, so you need to do some homework on this, although it seems to be a simple alteration, unless you follow the guidelines laid down in BS7671 and related building regulations, you will breaking the law and introducing non-compliances to you installation.

 

[masscrazy]

Not with one of those.
Nor can you 'run around the door'.

You will have to go under the floorboards above and reroute the cable so it has a straight drop to the new position.

You need one of these which are allowed to be hidden under the floor boards.

Unfortunately this is a loft conversion and floor boards are chipboard below.

So could you explain why running around the door is not acceptable?

You need to follow the permitted safe routes for cables (floors and walls)
Can be found here:
//www.diynot.com/wiki/Electrics:Installation-Techniques

Also when joints are made they cannot be buried or hidden within the fabric or voids of the building without being the type of joint that is considered maintenance free and a simple connector is not considered that.
You may also now need to have 30mA RCD protection on any newly installed buried cable, so you need to do some homework on this, although it seems to be a simple alteration, unless you follow the guidelines laid down in BS7671 and related building regulations, you will breaking the law and introducing non-compliances to you installation.

Thanks for bringing up the point about burying within walls and such as I was planning on putting it in the wall behind the plaster board.

 

[WabbitPoo]

Not with one of those.
Nor can you 'run around the door'.

You will have to go under the floorboards above and reroute the cable so it has a straight drop to the new position.

You need one of these which are allowed to be hidden under the floor boards.

Can you explain why that is permitted and a jb is not? Thanks.

 

[EFLImpudence]

It does not have screw terminals and is classed as 'maintenance free'.

 

[ekmdgrf]

You can't just route it around the door because anyone coming along in the future and inserting a fixture into the wall might get more intimately integrated into the lighting circuit than they would likely wish to be.

You can't bury a screw type JB into the wall as the screws tend to loosen over time and so the JB needs to be "accessible for inspection". I don't believe there is a clear definition of what "accessible for inspection" means and while one might deem a JB in a plasterboard wall readily available for inspection to one in possession of a lump hammer, it's likely that both the building inspector and the XYL will not see it that way.

I believe that EFLImpudence would prefer that you extend the cable by joining a new section on with crimps*

* Please ignore this in-joke.

 

[EFLImpudence]

 

[Aragorn84]

If you put a blanking plate in the old switch position, couldnt you go streight up from the old switch, across the safe zone above the door, then streight down into the new switch?

That would also mean the chock block connection is accessible by removing the blank?

 

[EFLImpudence]

You could but masscrazy may be married.

Another option with using the safe zone above the door (within 150mm. from ceiling) is to join the cable in an acceptable manner - you could solder (properly).

Others may have an alternative method but I couldn't possibly comment.

 

[conny]

Is within 150mm of a ceiling classed as a safe zone?

What I have in mind is if someone decides to put up some plaster coving and it needs supporting on nails till the adhesive sets. If the cable is run parallel to the ceiling but a few inches down then this poses a potential risk of nailing through it surely?

 

[ekmdgrf]

It does indeed. One needs to exercise extreme caution when nailing coving to the wall...

 

[EFLImpudence]

Is within 150mm of a ceiling classed as a safe zone?

Yes, I would tend to put the cable in the corner if possible, the same as in a vertical corner.

It would, I think, be silly to run it 140mm. from the ceiling.

 

[masscrazy]

If you put a blanking plate in the old switch position, couldnt you go streight up from the old switch, across the safe zone above the door, then streight down into the new switch?

That would also mean the chock block connection is accessible by removing the blank?

^ This.

Is this acceptable?

The blank plate would looks rubbish but at least the screw JB can be used inside the switch box.

Again why isnt adding the cabled within the architrave area acceptable (around the door)?

(Sorry bit lost with all the tech speak)