Light switch puzzle contd...

This is the diagram for the line side of a two way switched circuit.

L1 L1 0===========0 0===========0============= Line | \ / | C 0================================O C \ / \ / 0===========0 0===========0============= Switch return L2 Optional L2 |============= To second light Intermediate

Check both lights are on the same circuit (MCB or fuse, etc) If they are, you only need to connect the second light switch return to the existing switch return - tape up the second Line wire.

If they are on different circuits, this needs to be changed to the same one first.

"Dave Plowman (News)" wrote in news: snipped-for-privacy@davenoise.co.uk:

Thank you for the reply. I'm sorry, but not being an electrician, your diagram is difficult to fathom, as terms like "switch return" and "line" are not understood. Can you tell me which of the wires, on my coloured sketch, are the "second switch return" and the "existing switch return" that you mentioned above? And which is the "second line wire"?

I can confirm that both lights are on the same circuit.

Thanks...

Al

It looks as though he could probably remove the 2 gang double switch, join the two common wires and connect the remaining L1 and L2 wires to a single intermediate switch.

The right hand light needs to be disconnected from it's supply and directly connected in parallel to the left hand one. The existing switch drop cable between the switch and right hand light should be dispensed with, If the OP has access to the loft space above the lights this shouldn't be much problem

The labelling and/or colours going to the switches look a bit inconsistent. The OP needs to make sure he's really confident that he's mapped out the circuit correctly before attempting any changes otherwise he could see some quite "interesting" effects. I'd also strongly advise that he confirms each pair of ends with the power turned off by using the continuity or resistance setting on a multimeter and NOT by using a neon screwdriver with the power on.

Mike Clarke wrote in news:20120106151919.2edd9cf9 @curlew.lan:

Got it!!!

Where the old double switch was, I terminated the red live feed. I joined the two yellow (commons) together, and the remaining red-blue pairs wend to L1&L3 and L2&L4, respectively. It all works perfectly as planned!

Thanks for the help! Thanks also to all other respondees.

Al

With the older wiring colours, it was convention that the switch pair would be wired as red line, black switch return.

So after removing the two gang switch, connect the two yellow wires together and insulate.

Blue from the bottom of the stairs switch to 'in' on intermediate LI. Red """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""" L3

Insulate the red wire from the black and red pair and tuck out of the way

- it's not used.

Blue plus the black (from the black and red pair) from the landing switch cable go to 'out' on the Intermediate switch L2

Red from the landing switch cable to L4

Mike Clarke wrote in news:20120106151919.2edd9cf9 @curlew.lan:

Where the old double switch was, I terminated the red live feed. I joined the two yellow (commons) together, and the remaining red-blue pairs wend to L1&L3 and L2&L4, respectively, in the new intermediate switch. It all works perfectly as planned!

Thanks for the help! And thanks to all other respondees. I reckon you need a special kind of brain to be an electrician... and I ain't it!! :)

Al

"Dave Plowman (News)" wrote in news: snipped-for-privacy@davenoise.co.uk:

Thank you... I reckon that is exactly what I did, because it all works perfectly now!! What an improvement!!

Al

I would use it! I am not a big fan of live cables just left in backboxes.

I would connect it to the red on the 3 core from the landing light switch (ie terminal 4 of the intermediate switch using your wiring diagram).

"ARWadsworth" wrote in news:je7698$6c4$ snipped-for-privacy@dont-email.me:

L4 on my intermediate switch has a blue wire in it - not a red wire. Is L4 still the correct terminal to connect the terminated red live to?

Thanks..

Al

Wouldn't it be sufficient to terminate it in a single section cut off the end of a bit of chock-block terminal strip? This would avoid any future confusion being caused by the switches being supplied through two different routes.

It would be sufficient, however you already have a circuit that could cause confusion:-)

As you pointed out the best solution would be to completely remove the right hand lights switch wire and run a new cable between the two lights. However there is no right or wrong on this one (especially if the loft is boarded).

Time to think about Part P?

"ARWadsworth" wrote in news:je79mj$q74$ snipped-for-privacy@dont-email.me:

I'm really only concerned about a future surveyor unscrewing the switch fascia and seeing it. I don't want anything to create the impression that the house was wired by a cowboy (...even though it probably was! ;))

Al

I would not matter. There is no right or wrong way on this problem, I just gave my personal preference.

Anyway, if a cowboy has wired up your house then you should have a NICEIC certificate to prove so:-)

IIRC, that doesn't apply to repairs - only new stuff. Just where this job fits in is debatable.

And that would have been my second choice:-) Parallel the red and black at both the fitting and the switch (making both of them the switched live).

Either way, it does not matter as the OP has sorted his problem is a safe way.

Well it is not a new circuit and it is not in a "special location". Part P does not apply.

Having recently had a surveyor round, I'd say you wouldn't need to worry, even if every back-box contained an angry scorpion toting a hand grenade.

Admittedly, this was just a mortgage job...

Cheers,

Colin.

Part P does apply - the wiring must be safe. In this case the work isn't notifiable :~)