Bathroom extractor fan question

[adicosuk]

I have had 6 years ago installed a bathroom extractor fan which packed up last week, so I bought a "smart" one, with over-run of up to 30 minutes and humidity check.

I took the old one out and found 3 wires:
- yellow
- blue
- brown

the new fan has 3 x terminals:
- T
- N
- L

If I connect:
- yellow on T
- blue on N
- brown on L
I get the fan to run all the time, without stopping

If I switch brown with yellow, the fan will start when I pull the ceiling light cord and turn off as soon as I turn off the ceiling light.

What I want is that it fan starts when I pull ceiling light on and continues for 15-20 minutes AFTER I pull light off. I have used the internal fan settings to increase the timing, to no avail.

Do I do something wrong or it can also be maybe that I set the humidity level too low and as we are in UK and humidity is maybe at 60% lets say, I should try somehow to turn this to a higher setting?

thanks

 

[EFLImpudence]

Turn the humidistat up to maximum until you get it working.

The relative humidity in Guildford at the moment is 80%.

 

[Taylortwocities]

What make and model is the new one?
What make and model was the old one? Was it a timer fan?
Did you make a note of which conductors went to which terminals on the old one?

Yellow blue and brown are not standard colours.

Older 3 core cables were red blue and yellow. Is this cable two core and earth or 3 core and earth?

Do you have an AC voltage test device (NOT a neon screwdriver)?

 

[adicosuk]

New one was bought from here: http://www.ebay.co.uk/itm/201081600903?_trksid=p2059210.m2749.l2649&ssPageName=STRK:MEBIDX:IT - I think it is made in Poland, had good reviews.

Old one was a timer fan yes, but I dont know the model, and it does not write anywhere on it.

Yes I made a note, it also had 3 terminals, one L, one N, and another one with no marking (!!) the brown was to L, blue to N and yellow to the un-marked one.

I know yellow,brown and blue are not standard, the fact is that yellow is actually in a earth sleeving (!!) but it does not seem to be earth. It must have been live or switched live as the other fan worked on over-run. I have ONLY these coming out, as the hole is made into tiles, so dont know whats behind.

I dont have an AC voltage test.

Thanks, I thought it was a simple replace job...

 

[PrenticeBoyofDerry]

I dont have an AC voltage test.

With what you have described you need on and also a meter that can measure continuity.

I thought it was a simple replace job...

Schoolboy error, things are often not as simple as we think!

You need to test that you have a perm live, a switch live, a neutral and you should also have an earth/CPC at the fan, even if the fan does not require or have a terminal for this.
Once we can confirm what the conductors do and we have continuity, then we can then start to terminate correctly.

 

[adicosuk]

THANKS TO ALL FOR THEIR ANSWERS, BUT PARTICULARLY TO EFLImpudence, THE PROBLEM WAS INDEED THE HUMIDISTAT, I TURNED IT UP AND SUDDENLY THE TIMER WORKED A TREAT, SO I AM ALL SORTED OUT

ADRIAN

 

[ekmdgrf]

YOU'RE WELCOME

 

[Taylortwocities]

There is no need to SHOUT!