Neutral in switch box ?

[chainsawuser]

Hi

I've just replaced 2 light fittings in my house.
Both fittings were connected to a 2 way switching arrangement.

The first fitting (on the landing) has a cable (red, black, earth) coming in (from another light fitting) and another cable (also red, black, earth) going out (to another light fitting). There are also 2 red wires (and earth) coming into the rose (live and switched live). I have this fitting all working, no problem.

Now, the other light fitting (in the lounge) is also 2 way switched. I expected the same wiring arrangement as the landing light and therefore, I didn't make a note of the old connections. As before, it has a cable in and out (from / to other light fittings). However, instead of 2 red wires from the switch, there are 3 wires (red, yellow, blue)(and also earth). The red is live, yellow the switched live and blue is neutral (?). Back at one of the switches controlling this fitting, this blue wire (neutral) is connected to what appears to be neutral using terminal block. In the light fitting, I have commoned this neutral to the other neutrals. This light fitting also works normally.

I was just wondering why the 2 fittings are wired differently. The house is mid 1980s. The lounge switch is directly below the consumer unit. Therefore, is it wired differently because the power to all the downstairs light fittings passes through this switch ? Also is it correct for the this extra neutral to be commoned in the ceiling rose with the other neutrals ?

Thanks in advance.

 

[securespark]

You don't seem sure it is a neutral.

Do all light fittings work as before?

It could well be that the neutral is taken from the ceiling position down to the switch to feed another light not at ceiling level.

If you have a wall light, it has possibly been used for that.

The other scenario is that it could be another switchwire, connected through to another lights or lights.

 

[bernardgreen]

Or maybe triple and earth was used for the switch drop as well as the strappers and the blue is not used.

 

[securespark]

OP says the blue wire is connected to what appears to be a neutral in the switch box.

 

[chainsawuser]

You don't seem sure it is a neutral.

Do all light fittings work as before?

It could well be that the neutral is taken from the ceiling position down to the switch to feed another light not at ceiling level.

If you have a wall light, it has possibly been used for that.

The other scenario is that it could be another switchwire, connected through to another lights or lights.

Many thanks for the replies.

All the lights in house work okay.

Securespark, I think you have hit the nail on the head. There is an outside light on the same wall as the switch box (but outside the house). It makes sense to me now that the live and neutral coming down from the ceiling rose could be used to run this lamp too. In fact the switch for the outside lamp is part of a 2 gang switch (with the other side of the switch controlling the lounge light). I guess the way to confirm this would be to disconnect the neutral in the switch box and see whether the outside lamp stops working but the inside lights continue to work.

Anyway, I'm happy that the extra wire must be used to run the outside light. Also by connecting the neutral to the other neutrals in the ceiling rose, I have made the correct connections.

Many thanks again for your help.