Puzzled - how can it work

[moosehead]

I am replacing current lighting with some normal voltage halogens (thanks for advice on previous post)

I am somewhat puzzled by the wiring arrangement on a 2 gang switch, but I am sure one of the bright sparks here [every pun intended] will be able to explain in a trice.
There is only on cable serving the switch, with what appears to be a live loop between the two switches in the gang. The two switches then operate two separate circuits - one to the lights and one to an extractor fan. I would have thought that two separate cables would be required for each circuit but apparently not bot circuits work properly.
Just interested as to the theory behind this, I haven't yet looked at the junction box.

 

[pdcelec]

The permanent feed comes into the first switch and is then looped across to the second switch. There are then 2 switch wires which leave the switches and one goes to the light and the other to the fan

 

[moosehead]

Tks,
I'll have to double check but I was sure the cable into the switch was only t & e, but from what you are saying this cannot be the case?

 

[ban-all-sheds]

Well - it could be, but let's hope not, as if there is just the one cable, and it works as you say, then someone has been very stupid and naughty and used the earth conductor for live.

It could be one cable, but 3 core + E - what colours can you see? Can you post a photo?

 

[moosehead]

Thanks BAS.

Will have a look tonight when I get home and revert. Hope its 3 core + e. I assume that is a standard procedure, mind you the person who owned the house before us was a Ferry electrical engineer and a lot of the stuff we have found, whilst probably superb technical electrical engineering, looks very complicated.

 

[moosehead]

Checked the back of the box, Ban do you have a crystall ball - earth conductor tucked nicely into L2 and live as a wasps nest.

What should I do next. We do not/will not use the extractor so I can disconnect one of the circuits, however, slight issue, i want to run 8 x 50w halogens - can this be done off a 1 gang switch.

 

[pdcelec]

makes you wonder just how safe ferries are!

 

[moosehead]

quite - can we run 8x50w off a single switch?

 

[ban-all-sheds]

Yup

 

[Steve]

but please do something about the L2 earth!

 

[moosehead]

Worst thing is the 'earth' L2 live has yellow and green sleeving around it!!!

 

[Qedelec]

Noooooo!!!!!!!!!!!! run for the hills.

Anyone remember the marsioness

 

[ban-all-sheds]

Yup.

And the Herald of Free Enterprise...