Wiring a bathroom fan with humidistat, timer and pull cord

[andyp1981]

I just installed a bathroom fan with humidistat, timer and pull cord. I expected that the pull cord would be a manual override to turn it off and that when the pull cord is on the fan would work only if (a) the light is on (b) the timer has kicked in or (c) the humidistat kicks in.

However, what actually happens is this:

Pull cord off:
- Switch the light on and nothing happens. Switch the light off and the timer kicks in and runs for its duration, then the fan stops.
- If the humidity rises and the humidistat kicks in the fan switches on and runs until the humidity decreases.
- At no point in all this running does the red light switch on.

Pull cord on:
- The fan is permanently on, no matter what you do.

Model is Manrose XF100HP

It feels like this is just a miswiring problem but I can't get my little brain round it. Can anyone help?

Thanks

 

[riveralt]

As far as I know there is no switch live on this product. I cannot find wiring instructions online but if it has a permanent live, neutral and earth connection then the humidstat (which you can adjust) will activate the fan at the specified humidity level - and stay on until the humidity level drops below the specified level - at this point the timer kicks in and runs for the set time before the fan stops.
The pull cord acts as a full stop/override switch to the permanent live whenever it is pulled. It needs to be on so that the humidstat can kick in when required.
So not sure how you think your light with its normal switch live will link into your fan. If you have wired the lamp to the fan via the switch live then the fan/humidistat will not operate when the light is off because there is no permanent live.

 

[andyp1981]

Thanks riveralt.

I'm 99% sure that this model is designed to accept both permanent and switched live. The humidistat automatically runs on until the humidity has dropped a few % past the setting so it would not make much sense for this event to trigger the timer.

The whole point of the timer, as I understand it, is to be triggered by the light switch turning off and run on for a set period. As I explained, this is actually happening. I'm don't think you could replicate the situation I described with a fan that did not deal with a switched live.

The real peculiarity to me is why the timer is triggered by the light turning off but the fan doesn't actually turn on while the light is on!

Any further ideas?

The wiring instructions with it, by the way, were unhelpful because they gave details for humidity models, timer models and pull cord models but not the model with all three!

Thanks

 

[EFLImpudence]

This model requires no switched live according to this page.

http://www.discount-electrical.co.uk/PDFs/Manrose/100mm.pdf

I presume it only works on the humidistat or the pull-cord.

However it does have a timer so you may be able to utilise it if you know what you are doing.

 

[andyp1981]

A bit more research and the Manrose website says that this model 'requires no switched live'. Now I'm totally confused!

 

[ban-all-sheds]

I'm 99% sure that this model is designed to accept both permanent and switched live.

Not according to the people who make it.

http://www.manrose.com/specifications/100mmfanrange.pdf

But you have just installed it, so you should be sure, one way or the other, because you would have seen the terminals and would have seen whether there was one for a switched live as well as permanent, or just a permanent.....

The humidistat automatically runs on until the humidity has dropped a few % past the setting so it would not make much sense for this event to trigger the timer.

The people who make it think otherwise.

XF100H Humidity control which is adjustable between 40% RH and 95% RH
Complete with integral adjustable timer (1-20 mins)

XF100HP As above but with pullcord override switch. Requires no switched live

But if you don't think that makes much sense, why did you buy it?

The whole point of the timer, as I understand it, is to be triggered by the light switch turning off and run on for a set period.

But it's customary for the fan to start when the light is turned on, not off.

The real peculiarity to me is why the timer is triggered by the light turning off but the fan doesn't actually turn on while the light is on!

Please post photos of the wiring.