2-way light arrangement

[Athens2007]

Alright fellas,

Am no spark so i was hoping someone could give me a little piece of mind over the lighting arrangement i have for my landing light. The arrangement is:

Downstairs switch;
COM = RED live provided by a link from the Hall light switch com. (its a two gang swith)
L1 = BLACK Live
L2 = BLACK Dead

Upstairs switch;
COM = GREY going to the live in the light fitting.
L1 = BLACK coming from L1 downstairs
L2 = BLACK going to the neutral in the light fitting where it is linked onto a neutral from the Junction box in the loft.

The arrangement did not seem like a conventional one to me but am out of my zone on this stuff so any info would be much appreciated, thanks.

Oh yer and all the best!

 

[Taylortwocities]

What is the problem you are trying to solve?

Did it work and it stopped, what made it stop.

How are you testing those lives and deads
In a 2-way system the L1 will be live and the L2 dead, when you flip a switch the L2 will be live and L1 will be dead.

You will not have a neutral at the switch, so you haven't traced that upstairs L2 connection properly.
The L1s and L2s in the two switches should be connected together, nowhere else.

Have a look in the WIKI, there's loads of standard arrangements there.

 

[Athens2007]

The light switching works as its supposed to so there is not a problem in that sense. I suppose the problem is that i don't understand it!

Most of the conventional methods i have looked at have more than three wires in at least one of the switches.

I did think that it could be the "cable saving method" as shown in the Wiki but on the setup i have its the common from the switch which feeds the live in the light fitting.

I tested the potential with a Fluke.

Quote: You will not have a neutral at the switch, so you haven't traced that upstairs L2 connection properly.

I pulled the wire back up into the loft to where the light fitting and junction box is situated, so even i couldn't have got that one wrong!

 

[333rocky333]

If the common feeds the light, then the live supply has to be on common at the other switch.

This is quite normal and you only need Two strapper cores + earth between switches

 

[Athens2007]

It certainly is mate - but its fed by a link off the com of the hallway light, is that ok?

 

[Taylortwocities]

It certainly is mate - but its fed by a link off the com of the hallway light, is that ok?

It might be a problem later.

Is this link (live) from the downstairs lighting circuit?
and
is the neutral for the upstairs light from the upstairs lighting circuit?

If that is the case then you have what is called a 'borrowed neutral'

This will cause grief if the consumer unit is upgraded to a dual RCD type (aka "17th edition compliant" ).
You will have tripping problems if the two lighting circuits are on different RCDs. This was not an issue with older non-RCD systems.

 

[ban-all-sheds]

It will also cause you grief if you switch off one circuit to work on it....