bathroom ceiling light and extractor fan question

[motown]

Hi,

I had an electrician do some jobs in my house. He installed an extractor fan in the bathroom and it works fine. However, it turns on as soon as I switch the light on and I'd prefer it not to (it has a humidity sensor, so I want it to just come on when it reaches a certain level of humidity). I imagine that this is an easy enough fix to do myself, but would appreciate some advice to make sure i'm doing it correctly.

Here is a link to the instruction sheet (I have the CHZ model) http://www.solerandpalau.co.uk/docs/manual/0288170012_____silent_100_(10_05)_fid5744.pdf
It seems that he has installed like fig. 8, whilst I wanted it installed like fig. 9

I can very easily isolate the power and remove the connection to the switched live from the fan, a sleeve has been placed around it. When looking inside the ceiling rose - a sleeve has been placed around a neutral wire and in the isolation switch outside the bathroom, there is a sleeve around one of the live wires and one of the neutral wires.

I imagine that the sleeves have been put on to identify the wires that are to do with the switched live on the fan. So the switched live on the fan connects to the sleeved live on the switch and the sleeved neutral on the light connects to the sleeved neutral on the switch. What I'm keen to know is, if I disconnect all these wires (obv with the power switched off), will the fan work as I want i.e. will not come on with the light, but just when humidity reaches the set level?

I will check that the wires are connected as I suspect when I start unconnecting the wires and if I found that it's connected differently then I'll put everything back as it was.

Thanks in advance for any advice

 

[EFLImpudence]

It seems that he has installed like fig. 8, whilst I wanted it installed like fig. 9

You have already found the answer.

Just remove the switched live from the fan and make it safe as, obviously, it will be live when the light is on.
No need to alter anything else.

 

[motown]

Great - thanks! Wasn't sure if I needed to remove all the wires for safety. I'll just put the switched live in a terminal block. Thanks again

 

[ericmark]

As to safety putting in a terminal block is likely fine. The only question is complying with building regulations.

If you read Part F from memory I think it details where a fan is required and how it should be activated. As an extra to requirement you can switch it any way you want but if it's there to comply with regulations then it needs switching as laid down in the regulations.

I have questioned many times the switching on with lights as only if there is no natural light would that be a valid method.

I have had problems with humidity controls and I would advise you always need a way to isolate a fan so if it fails in any way you can switch it off.

My preferred way to control a fan is a simple pneumatic push button as it complies with building regs, easy to fit, and gives user full control.

As to sleeved wires. It is common where the neutral coloured wire is used for switched line to sleeve the wire with the line colour.

Note since both neutral and the phase wire are both considered live we call the phase wire is a single phase supply "line".