two way hell

[bodge]

I have tried to replace a ceiling rose on the landing operated by a two way switch and smugly and stupidly did not mark the previous connections to copy. Now i can't get the two way to work and don't understand how it ever could have in the first place.

The power to the rose comes on a single two core and earth from another rose. The unstairs swtich has a two core running from L1 and L2 to the rose. A single core cable runs from the common to the rose. No other cables run from or to this rose or switch.
The second switch is a two gang switch. L1 and L2 have a two core cable running from somewhere? The common is connected directley to the common of the other switch in the two gang box. Again no other cables.
I have been through the attic and can find no connection from the second switch to either the first nor the rose.
I can make the first switch work but cannot get any two way operation nor any response from the bottom switch. I can also make the light operate from any o fthe bedrooms which is only of limited use really.
Help

 

[plugwash]

it sounds like you have a right old bodge there i certainly can't figure it out

id say your best bet is to rewire the switch drops from scratch in the modern way useing 3 and earth cable

 

[breezer]

there is a junction box somewhere, it is the "other way " of 2 way switching, but it would be best to re wire it

 

[MANDATE]

Hi bodge!
As you may be aware there are two ways of wiring a couple of two way switches.
It sounds as though yours is the older method.
First a 'live' was taken to 'com' on switch No 1, this live may or may not have come the ceiling rose ( it doen't matter)
Next the 2 core plus earth strapper cable linked the 2 two way switches together. that is L1 to L1 and L2 to L2.
Then from 'com' on switch No 2 the 'switched live' would go to the ceiling rose, which connects to the brown in the flex to the bulb.
After the bulb the other wire is the blue which goes up to ceiling rose and connects to the 'neutral' (black).
The modern method has the 'live' and 'switched live' going to the same two way switch (L1 and L2 ) and the strapper cable is 3 core plus earth, these being red, yellow and blue red goes 'com' to 'com' yellow 'L1' to 'L1' and blue 'L2' to 'L2'.
The modern ceiling rose acts as a junction box and has three blocks of terminals. 1st two terminals 2nd three terminals 3rd three terminals.
Incoming 'live' to block 2.
incoming 'neutral' to block 3
Outgoing 'live' from block 2 to switch No 1(old method, unless it has been supplied from another source)
Return 'switched live' from switch No 2 (if old method) back to block 1 on rose.
lamp connects brown to block 1 and blue to block 3, where the neutral is connected.
If you are to feed another rose in another room, then a outgoing cable will be needed . that is 'red in block 2 and 'neutral' in block 3

 

[securespark]

Man

I may have read it wrong, but from what bodge says, the strappers terminate in the rose, along with the feed and the switchwire. This does not make sense unless the strappers have something else to connect to?

 

[ban-all-sheds]

I have tried to replace a ceiling rose on the landing operated by a two way switch and smugly and stupidly did not mark the previous connections to copy. Now i can't get the two way to work and don't understand how it ever could have in the first place.

But it did, didn't it....

Go back to first principles - disconnect all the cables, work out which one is the permanent live, which ones go to the switch, the next rose etc, and then connect it all up properly.

The power to the rose comes on a single two core and earth from another rose. The unstairs swtich has a two core running from L1 and L2 to the rose.

I doubt that that is so.

A single core cable runs from the common to the rose. No other cables run from or to this rose or switch.
The second switch is a two gang switch. L1 and L2 have a two core cable running from somewhere?

Are you sure it's not from the first switch?

I can also make the light operate from any o fthe bedrooms which is only of limited use really.

Do you mean that the landing light can also be turned on and off by any of the switches in the bedrooms?

 

[securespark]

If another switch is operating a light not associated with it, then you have the incoming and outgoing feeds muxed ip.

 

[bodge]

Man - spot on it seems to be wired the old way as you said. I got confused as i though i was missing a cable and what i thought ran to the switch goes a different direction under the floor.
Many thanks

PS being the old way - is it still legal?

 

[ban-all-sheds]

At the moment the wiring regs do not have the force of legality.

There are those who will say that the resulting single-conductor use will cause overheating due to eddy currents, but I am unconvinced.

If you have separate circuits for upstairs and downstairs lights then make sure that you don't have a borrowed neutral, i.e. a light being fed with the live from one circuit and the neutral from another, as this can be dangerous.