Wiring up 4" Extractor Fan with Timer & Humidity sensor just for Humidity mode

andyr123

andyr123

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Hello - I have this 4" Extractor Fan with a Timer and Humidistat circuit board in it - there are 2 adjuster screws (pots) and one is for timer, one controls humidistat. For using timer you need 3 wires, 1 neutral, and 2 Lives (1 switched live, 1 permanant live) - the wires I have coming into the fan from the ceiling light are just 2 wires (live & Neutral) but for Humidity control I am thinking that it should only work with 1 live (ie, you only need 2 lives, one switched and one permanent live if you want to use it as a timed extraction)

so, its wired with 1live(switched) and neutral. Now, the Humidity screw according on the box should be turned fully clockwise so I have done that, the Timer screw, if I turn the timer switch all the way anticlockwise (even though it isnt wired up for timer operation) the fan stays on permanently, if I turn that timer screw clockwise the fan doesnt come on at all even when there is humidity, same if I put the timer switch to the middle. - so in other words the fan is either on permanently or off permanently and wont come on even when moisture is about - had two of these fans and they are both acting in the same way (just to rule out if the fan/circuit board is faulty) if I put a link wire from the live terminal, and the switched live terminal the fan is on permantly, it doesn't even go off even after something like 20mins.

I wonder what is going on here? - should be able to just use the fan in Humidity mode with just the live and neutral from the ceiling light shouldnt I? or the Live & Neutral or a link from the live to the permanent live connector of the fan shouldnt I?

Here's a pic on the box of the wiring diagram:

14908200_10210409516048070_7187562397639395830_n.jpg
 
With it connected only to the switched live, it will always be off when the light is off. Is that what you want?
 
They don't normally work at all unless you link PL and SL.

You have to have the humidistat up fairly high for it to stop.
Don't know exactly where you are but, just had a look, the humidity in Dublin at the moment is 91% so if you have it set to 40 it will probably be on permanently.
Humidistats are not really very good in the British Isles.
 
endecotp said:
Err, if you want it to come on only on the humidistat then you don't want to link them, no.
Linking them would make it permanently on.
Click to expand...
Yes, that's true - but op said:

"so, its wired with 1live(switched) and neutral. Now, the Humidity screw according on the box should be turned fully clockwise so I have done that, the Timer screw, if I turn the timer switch all the way anticlockwise (even though it isnt wired up for timer operation) the fan stays on permanently,"

I think I still got it wrong.




That's outside, though....
Click to expand...
It is but I was making a point.
 
andyr123 said:
For using timer you need 3 wires, 1 neutral, and 2 Lives (1 switched live, 1 permanant live) - the wires I have coming into the fan from the ceiling light are just 2 wires (live & Neutral) but for Humidity control I am thinking that it should only work with 1 live (ie, you only need 2 lives, one switched and one permanent live if you want to use it as a timed extraction)
Click to expand...
Is that what the instructions say? If so, they are probably telling the truth!

That seems to make sense. If the functionality was such that the fan would come on when the light was switched on (and stay on for a timed period after the light was switched 'off'), regardless of the humidity level, then you would need the switched live as well as a permanent live - but a switched live (switched by the lighting) would seem irrelevant if you wanted the humidistat to switch the fan on/off regardless of the light. Similarly if (unusually) it was designed so that the light/timer over-rode the humidistat (i.e. the humidistat would only turn fan on if the light was on).

Can you get it to work in 'timer mode'? - i.e. 'disable' the humidity sensing (turn it fully clockwise??) as much as you can, connect just the permanent L, then (if you can do it safely) briefly link permanent and switched live terminals. The fan should then come on and remain on for the set timer period.

Can you tell us the make/model of this device? It looks as if it may have 'lost something in translation', since they seem to have written 'Hydrostatic' when they mean 'Humidistat' (or 'Humidistatic') - which makes one wonder!

KInd Regards, John
 
Hello all - thank you very much for your replies and very sorry never got back sooner. - I put a weather station with a humidity reading on it and it never went over 67% so thats most probably why in never came on, have since removed the fan and took it back to shop and just open up window now to let steam out when there is any :D

Thanks again
 
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