Permited cable route

[Robojin]

Customer wants to replace a 4 gang flying lead, with a concealed spur from the ring on an adjacent side stud wall (run of 2m) and above that a single for LCD TV, ring circuit is RCD protected (yet to check Zs etc)

I'm having one of those days with OSG interpretation, the short route is a fused spur running parallel above the skirting (existing accessories hight) to the new twin socket & vertical to single socket (for TV), however is this permitted even with RCD protection? ?:| or have I still got to go up within 150mm, across at the TV single hight level and down to the twin (IMHO this route is more likely to be hit if future owner puts up a wall shelf for example)

Next minor problem is getting to the dry lining box of the ring to spur and the small matter of the wall angle where there will be a stud right in my way (next problem), I tried to convince the customer that this would be VERY expensive just to hide 2m of extension lead, but they seem to have deeper pockets than I gave them credit for :|

 

[green-hornet]

Yes it is permitted, the safe zone extends horizontaly and vertical from any visible point, so going from what you describe it is permitted.

It only gets dodgy if you run the cables at angles from the sockets, this way there is no way of knowing when a picture is hung where the cable is.

You can channel out the stud normally a bit of 3x2 and screw the side of the dry line box direct to the timber, just remove the plasterboard grip until it fits snug, or you could fit a metal back box.

 

[Robojin]

Yes it is permitted, the safe zone extends horizontaly and vertical from any visible point, so going from what you describe it is permitted.It only gets dodgy if you run the cables at angles from the sockets, this way there is no way of knowing when a picture is hung where the cable is.

You can channel out the stud normally a bit of 3x2 and screw the side of the dry line box direct to the timber, just remove the plasterboard grip until it fits snug, or you could fit a metal back box.

Cheers GH, so unless I misunderstood I can take the most direct route, also if I recall I don't have to put the new Twin at 450mm (customer would get the right rat if I did) as this is just an addition?

What are the chances of me temp removing the dry wall box out without messing the plasterboard? (it's not fixed to any stud at the mo)

 

[green-hornet]

The new hieghts only apply to new builds or major refurb where restricted access is to be expected, so you can set all fixtures at current height(providing they are not in the skirting)

The dry line box should come out very easily without any damage to the plasterboard.

Just take socket cover off, and using a re threader screw into the lug push it all the way back then pull it inwards and it should just slide out.

 

[Andy™]

The new hieghts only apply to new builds or major refurb where restricted access is to be expected, so you can set all fixtures at current height(providing they are not in the skirting)The dry line box should come out very easily without any damage to the plasterboard.

Just take socket cover off, and using a re threader screw into the lug push it all the way back then pull it inwards and it should just slide out.

but there is something about you cant make them any more inaccessible than they already are

 

[green-hornet]

The regulations state most items for switching and isolation should be easily accessable,and within a safe and minimum distance.(and correctly labelled etc for use)

Therfore you have a duty to not to introduce a possible hazard into any installation.

This would cover what you have suggested andy(I think)B-)

 

[Gforce]

My interpretation of it was if you cant fit within one of either safe zones or channelled 50mm or mechanical protection it should be rcd protected-so if rcd'd doesnt matter about zones.

Not trying for one minute to say a time served excellent sparks like hornet is wrong but thats how it reads imho.

 

[Andy™]

My interpretation of it was if you cant fit within one of either safe zones or channelled 50mm or mechanical protection it should be rcd protected-so if rcd'd doesnt matter about zones.Not trying for one minute to say a time served excellent sparks like hornet is wrong but thats how it reads imho.

No. All cables in walls must be RCD'd unless they are 50mm deep or mechanically protected. but if its in a zone, then you can get away without the mechanical protection/50mm deep, and clip direct/cap over

 

[green-hornet]

My interpretation of it was if you cant fit within one of either safe zones or channelled 50mm or mechanical protection it should be rcd protected-so if rcd'd doesnt matter about zones.Not trying for one minute to say a time served excellent sparks like hornet is wrong but thats how it reads imho.

The safe zones have not been changed from the last 16th edition and remain in force.

What we have now with the 17th edition is the 50mm depth and wall issue and the additional protection by rcd for such cables.

The main area where this has a dramatic effect is the lighting circuits, which now require rcd additional protection if the cables are installed within 50mm of the final surface.The cables are most likely to be still installed to traditional methods which will almost always be in a safe zone, but would still require additional protection by way of a rcd.(or be suitably protected from damage etc etc etc).

The main concept of a safe zone was the idea that a cable is expected to be present in that area, and any damage done to a cable so positioned could not be attributed to negligence on the behalf of the installer.

Cables are hidden but still expected to be present.

 

[Gforce]

I think we are on the same page here to be honest-just when you said about not doing it at say an angle I was kinda thinking it would be ok if mech protection or rcd'd, as was essentially safe-also I do believe even if it isnt rc'd or mech protected if it is essentially obvious what ditance it is from say being able to look through a door it is classed as a safe zone too.

Not that i would personally say at angles was good practice.Blushing

Oh how that part of the bs7671 gave me headaches lol.

Hope everythings going ok with work guys.Guiness Drink