Wiring ceiling rose in new build - two-way switched

[Stardust8324]

Hi peeps!

Got a phone call from a mate who has just moved into a new build flat at the weekend - he'd tried to replace the existing light fittings with a fancy new one, but did the usual 'unwire the old ceiling rose, wire all the colours together and trip the circuit breaker' routine.

To get him back up and running, I popped around to take a look. Usual script: three separate twin and earth cables coming out of the ceiling, so we stuck my multimeter across them (with the electric off I hasten to add) and continuity tested them to identify the switch cable, which we duly did. Wired it all up correctly to the fitting, flicked electric back on and hey presto, we have light

What I didn't realise at the time (and only found out about when I got home) was that this particular light was two-way switched and now the light doesn't work off the 'other' switch. I'm sure that all the cables out of the ceiling were twin and earth so how can we have wired up the ceiling rose incorrectly? Surely two of the cables are feed in and feed out and one is a switch cable? Or can you have two switch cables coming out of the ceiling and we have just wired it up wrong?

All help appreciated

 

[rebuke]

The most common way of doing 2-way switching is to have a 3C+E between the two switches, and then just a switch wire to one of them, I can't see how it could be done at a ceiling rose with just 3 T+Es (given one of them must be the supply), certainly not in a way that wouldn't have caused another trip when your mate used the other switch.

I suspect when it tripped the first time it may have welded the contacts in one of the switches, hence why it doesn't work from that switch - try replacing it...

 

[ColJack]

you don't specify what this particular light is..
landing light?

 

[Stardust8324]

It's a light in the flat's 'hallway' (ie inside the actual residence, not in the communal hallway) but it's such a small place I didn't realise that it had been installed with two light switches operating the one light (apparently the switches are only about five feet apart!!)