Linking Across... SWITCHES

[Jabbajaws]

(Apologies to Moderators, tried to place this thread in correct forum, but forum was full and not accepting any new threads).

When changing light switches, l have noticed (quite a few times) is that a link wire has been used, to carry out a live from one switch to another (2 gang).

What l would like to know is are we permitted to do this under 17th regs? (linking across rather than proving a separate live).

Are there any safety issues by doing this?

Feedback welcome...

 

[Sickmick]

Can't think of a reason not to do it, but surely from a wiring point of view it's simpler to run a live and switch return to each lighting point. You mostly see this where lights are wired from 1 crowded juction box with no loop in at each pendant.

Possible safety issue is the old crossed neutrals on 2 way switching on stairs.

 

[Jabbajaws]

Cheerz Sickmick, its not a practice that l do myself, but l do see it quite a lot in older houses and just wondered more than anything...

 

[Sickmick]

Think it was common practice a few years ago, if you get chance to get under floorboards look out for the junction box, always seem to have the cpcs twisted together outside the box. Pain in the arse to make additions to.

 

[malcolmsanford]

Sometimes seen in domestic this is prevelent a lot on conduit grid switching in commercial/industrial units.

If the grid switch is fed from a single circuit then yes quite often you would link the LINE common at the switch. Of course often you would get grid switches that will have 3 phases in them, and these would be suitably marked to let the next person to work on this be aware.

 

[geordie]

came across this last week in a new build

 

[fredrico]

They even show you at college to link the lives across, on certain switches, well they did for us a few years ago. And that was to the 17th regs.

 

[Ponty Massive]

Nothing wrong with that. Ran a 3-core in for a fan light the other week, link in the switch to feed the seperate switch wires for the fan / light.

 

[ezzzekiel]

apart from the old borrowed neutral issue which is where it is most commonly seen - otherwise not a problem

 

[Jabbajaws]

Thank you all. As long as its not prohibited, then its not up to me to correct, which is what l was thinking l would have to do in the event of finding one...

 

[Engineer54]

Thank you all. As long as its not prohibited, then its not up to me to correct, which is what l was thinking l would have to do in the event of finding one...

Far from being prohibited, this is a standard wiring method. Why on earth would you want to bring separate switch feeds in, for a multi gang switch?? Just think for a moment, ....in a conduit installation, with multi ganged grid switches. Generally, it's common practice to bring in a separate switch feed for each row of grid switches, for a multi row, multi gang grid switch. If every switch came with it's own switch feed, then the conduit size would need to be much larger, than the conduit containing looping switch feeds!! Obviously, the overall lighting circuits must conform to all the other relevant circuit criteria etc...