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[Proz]

Hello
Im looking for some advice from an electrician if theres any about .... basically i thought i'd replace the bathroom pull witch with a shiney new on to match the bathroom decor . The bathroom has only one light and one light switch but there is a fan that comes on with the light and runs for 5 mins or so afterwards .
So i unscrew the one thats there and see 3 red wires going into one terminal and a red one and a yellow one going into another .....


So the new switch looks like this below ..... where do i start 



Thought this would be easy 

[Lizzie_Zoom]

That yellow one should be an earth...............but it is joining a live, which normally would be the return for the switch. 

I would need to check that yellow with a circuit tester, as to me, it should be as dead as earth's usually are!

Two of the reds in to the connection on the left are part of the ring circuit. The third red no doubt goes to the fan unit, with a return, the red on the right, coming back to the switch unit to complete the circuit when the switch is closed.

Still baffled though about the yellow (it should also have green stripes), and I would have to be on site to know more after testing.

I  hope that helps, but I suspect another, currently professional electrician, will give better advise.  

[the alarming man]

well it is easy....one lot of wires will goto common live and the other lot will goto the other side of the switch

i would say the red with the earth might be you live feed to the switch the 3 wires twisted together is your feed off to appliances...i.e your light

[STMO123]

I'm no sparky but that looks like neutral/earth one side and the live loop on the other.

[Kevin Wood]

Green and yellow would be an earth. 

Red, yellow and blue are often (with the pre-harmonised colour scheme) used as live in triple core cable in 2 way switched lighting circuits, and so on. I'm guessing in this case that the yellow is a switched live to the fan, the red on that terminal is a switched live to the light, and the three red conductors in the other terminal are 2 permanent lives forming part of a lighting ring and maybe a permanent live to the fan, if it has a timer built in.

All that is required is to make the same connections to the new switch.

[Proz]

That yellow one should be an earth...............but it is joining a live, which normally would be the return for the switch. 

I would need to check that yellow with a circuit tester, as to me, it should be as dead as earth's usually are!

Two of the reds in to the connection on the left are part of the ring circuit. The third red no doubt goes to the fan unit, with a return, the red on the right, coming back to the switch unit to complete the circuit when the switch is closed.

Still baffled though about the yellow (it should also have green stripes), and I would have to be on site to know more after testing.

I  hope that helps, but I suspect another, currently professional electrician, will give better advise.

Im usually not bad at this kind of thing as ive changed all the lights in the house and put up fans etc but this one threw me ... I'll maybe just get an electrician in 

[Lizzie_Zoom]

Green and yellow would be an earth. 

Red, yellow and blue are often (with the pre-harmonised colour scheme) used as live in triple core cable in 2 way switched lighting circuits, and so on. I'm guessing in this case that the yellow is a switched live to the fan, the red on that terminal is a switched live to the light, and the three red conductors in the other terminal are 2 permanent lives forming part of a lighting ring and maybe a permanent live to the fan, if it has a timer built in.

All that is required is to make the same connections to the new switch.

But as I stated Kevin, the yellow appears to be the earth, that should be connected to it's own terminal, as it is clearly in an earthing sleeve that we normally use to cover the bare copper of an earth cable. Indeed if you look at the unit in the other picture the earth terminal is unused, which is not correct.

I suspect the earth is wrongly connected.

[Proz]

Green and yellow would be an earth. 

Red, yellow and blue are often (with the pre-harmonised colour scheme) used as live in triple core cable in 2 way switched lighting circuits, and so on. I'm guessing in this case that the yellow is a switched live to the fan, the red on that terminal is a switched live to the light, and the three red conductors in the other terminal are 2 permanent lives forming part of a lighting ring and maybe a permanent live to the fan, if it has a timer built in.

All that is required is to make the same connections to the new switch.

So as long as the three reds go together at one side and the red and yellow go to the other side thats it ?  Does it matter where the 3 reds go as theres COM-L , L1 and L2 markings on the new one .

[Kevin Wood]

The three red wires from one side of the switch co into the COM-L terminal of the new switch.

The red and yellow wires from the other side both go into either L1 or L2 of the new switch. Doesn't really matter which. Job done.

Obviously make sure it's all isolated before you start and make sure you mark the wires or keep them grouped so they don't get confused.

[Kevin Wood]

Green and yellow would be an earth. 

Red, yellow and blue are often (with the pre-harmonised colour scheme) used as live in triple core cable in 2 way switched lighting circuits, and so on. I'm guessing in this case that the yellow is a switched live to the fan, the red on that terminal is a switched live to the light, and the three red conductors in the other terminal are 2 permanent lives forming part of a lighting ring and maybe a permanent live to the fan, if it has a timer built in.

All that is required is to make the same connections to the new switch.

But as I stated Kevin, the yellow appears to be the earth, that should be connected to it's own terminal, as it is clearly in an earthing sleeve that we normally use to cover the bare copper of an earth cable. Indeed if you look at the unit in the other picture the earth terminal is unused, which is not correct.

I suspect the earth is wrongly connected.

I disagree. It's not in an earth sleeve. That looks like a yellow coloured insulated cable not an earth conductor with a yellow and green sheath over it.

It also looks to me like it's wired in with the switched live conductor from the switch. Yellow is a valid colour code for such use, so I'd be very surprised if it's an earth. If it was, it would have tripped the breaker by now, anyway.

[Lizzie_Zoom]

Green and yellow would be an earth. 

Red, yellow and blue are often (with the pre-harmonised colour scheme) used as live in triple core cable in 2 way switched lighting circuits, and so on. I'm guessing in this case that the yellow is a switched live to the fan, the red on that terminal is a switched live to the light, and the three red conductors in the other terminal are 2 permanent lives forming part of a lighting ring and maybe a permanent live to the fan, if it has a timer built in.

All that is required is to make the same connections to the new switch.

But as I stated Kevin, the yellow appears to be the earth, that should be connected to it's own terminal, as it is clearly in an earthing sleeve that we normally use to cover the bare copper of an earth cable. Indeed if you look at the unit in the other picture the earth terminal is unused, which is not correct.

I suspect the earth is wrongly connected.

I disagree. It's not in an earth sleeve. That looks like a yellow coloured insulated cable not an earth conductor with a yellow and green sheath over it.

It also looks to me like it's wired in with the switched live conductor from the switch. Yellow is a valid colour code for such use, so I'd be very surprised if it's an earth. If it was, it would have tripped the breaker by now, anyway.

You would have thought so, but before now I have uncovered a "live" earth.

[STMO123]

Leave it, Lizzie.

[Lizzie_Zoom]

Leave it, Lizzie.

Yes, you're right Steve.  Best eh!

I have touched enough 'lives' in my time!  I love the tingle though.  It gets me all excited!

[Proz]

Leave it, Lizzie.

Yes, you're right Steve.  Best eh!

I have touched enough 'lives' in my time!  I love the tingle though.  It gets me all excited!

Love a good tingle me too  ... Thanks for the help folks