Change Switch so extractor fan not linked to light

[ryan1971]

I want the add a double switch so that the extractor fan is operated separately from the light & not on every time the light is

Currently a single switch

Yellow/Green to side nut
One Red & One Yellow cable to top port
Two Red to L2
The remainder of wires black/blue are on a cap



Any advice welcomed or let me know if you need more info

Cheers

Ryan

 

[ericmark]

There is no standard wiring colours when using cable with wrong colours all line wires should be Brown (was red) and all neutral Blue (was black) and green/yellow is earth. When using other colours with single phase as in most houses then sleeves should be put on wrong colours so red sleeve on a yellow wire. However this is rarely done.

Fans with sometimes have an earth and always a neutral and either one or two line feeds one will be permanent line the other only line when the fan is switched on.

The three live wires that's neutral and two lines will be feed through an isolator normally with a insignia or fan written on it this is used to turn off the fan if there is a fault. If this has been omitted then simple to fit as you just break all of the three wires to wire it up.

However if you want to install a different way to activate then a little more involved you need to work out which wire is which.

The normal way is to use a pneumatic push button these can be set to a fixed time either as well as lights or instead of lights. Instead again quite easy but to do as well needs the light switch changing for a double pole.

From what you say you just need one of these all different styles.

Does this help at all.

 

[PrenticeBoyofDerry]

Do you have a safe means of testing for voltage?
What core colours are at the fan and at the light?

 

[OwainDIYer]

I want the add a double switch so that the extractor fan is operated separately from the light & not on every time the light is

Currently a single switch

Yellow/Green to side nut
One Red & One Yellow cable to top port
Two Red to L2
The remainder of wires black/blue are on a cap

possibly

red and yellow - live and switched live to fan (timer fan with timer over-ridden)
2 red to L2 - live loop in and out at switch
blacks and blue - neutrals looping through and to fan

In which case you may not have a live feed from the switch to the light, it may be connected at the fan, and you will not be able to disconnect the fan at the switch without also disabling the light. You would need to find where the light is taken off the fan cable and separate the fan and light supplies there.

what colour wires are inside the light?

 

[PrenticeBoyofDerry]

I'd say they will be either two singles or possibly a twin red going to light and a three core (BRY) to fan.

One red of singles/twin is perm live other switch to light
One red of three core perm live, yellow switch (could be visa versa) and blue neutral to fan.
But pure guess work without testing for voltage and investigating at light and fan.

 

[ryan1971]

I guess not as simple as i thought it would be, i'll unwire the light later, the one thing i can say is taking one of the reds from L2 disables the fan, but when i place this in the second switch i'm not sure which other wire should move to that switch from the top port.

tried moving the red from top port and then everything stopped, but i havent tried putting the yellow over to second switch yet.

i'm a novice if you haven't guesses

 

[PrenticeBoyofDerry]

are cables sheathed at all generally grey, they may come in sets, I would expect one set to be blue, red, yellow and a cpc/earth (bare copper sleeved green/yellow)

And the remaining reds could be twined with a cpc or could be single.
Before you do disconnect make a note of where are currently positioned and identify each red individually by making the cable suitably.

What you need to do is identify which core or cores are permanently live, the safest way to do this, is by safely isolation, prior to removing covers, then using an approved voltage indicator to prove the circuit is dead, then you can remove cores from terminal, ideally connecting to terminal block, then make live and test the line conductors against earth and neutral, also test neutral to live. This will hopefully ID your perm live and polarity is correct.

I would also investigate for core colours at the light and fan, this will be very helpful for you to move forward and end up with the desired configuration.