Faulty extractor fan

kkelly77

I've just finished wiring up an extractor fan I'm fitting in the bathroom but it's not working.

For simplicity sake, I've taken the L and N off one of the downlights and have routed a cable to the Common terminal on the light switch for the timer. Continuity test is good and I'm getting a reading of 10.9V across the fan when the lights are switched on. Any help what I've done wrong or have I got a bogey fan? Thanks.

2011

I am not 100% clear on the wiring you have described.

What voltage is the fan?

What is the power consumption of the fan?

What voltage are the downlightwers? If 12VDC, what rating is the transformer (VA)? I am guessing that it is not large enough to supply both the 12V downlighter and the 12V fan.

If the fan is manis voltage you should have 230VAC between the neutral and the permanent supply.

Dont forget the fan isolator!

kkelly77

2011 wrote: »

I am not 100% clear on the wiring you have described.

What voltage is the fan?

What is the power consumption of the fan?

What voltage are the downlightwers? If 12VDC, what rating is the transformer (VA)? I am guessing that it is not large enough to supply both the 12V downlighter and the 12V fan.

If the fan is manis voltage you should have 230VAC between the neutral and the permanent supply.

Dont forget the fan isolator!

Sorry for not replying sooner. I disconnected existing wiring from the fan and I connected a length of flex to a plug so I could test the fan directly from a socket. Still not working. Looks like a faulty unit.

The documentation that came with the fan doesn't list fan voltage or power consumption. I didn't even check the voltage of the transformer for the downlights (6 x downlights in total)

maxfresh

Well where you feed off the common terminal of the switch this is 230 v, so i would presume the fan is a mains type and not low voltage.

So take the live and neutral from the mains side of your downlight (and through a triple pole isolator with the perm live from common of switch)

kkelly77

maxfresh wrote: »

So take the live and neutral from the mains side of your downlight ....

That's the way I had it wired up. As we know the fan is 230V, I assume my test with the fan plugged directly into a socket to test it, confirms the fan is in fact faulty?

Would a fused spur be suitable to use instead of a 3 pole isolator?

meercat

if there is a timer on the fan you need to to loop a wire from L to L1 on the fan unit itself for the test to work


you need one of these isolators
http://www.wickes.co.uk/6a-fan-isolator-switch/invt/710430/

maxfresh

kkelly77 wrote: »

That's the way I had it wired up. As we know the fan is 230V, I assume my test with the fan plugged directly into a socket to test it, confirms the fan is in fact faulty?

Would a fused spur be suitable to use instead of a 3 pole isolator?

The 3 pole is used because you have
permanent live
switched live
neutral

A spur is only a 2 pole

kkelly77

meercat wrote: »

if there is a timer on the fan you need to to loop a wire from L to L1 on the fan unit itself for the test to work

I've just tried that Meercat and it worked

Does this mean I need the same loop wire setup when I have the fan reinstalled in the attic? Won't that just keep the fan on permanently?

maxfresh

kkelly77 wrote: »

I've just tried that Meercat and it worked

Does this mean I need the same loop wire setup when I have the fan reinstalled in the attic? Won't that just keep the fan on permanently?

Take the loop of wire out you will have the two feeds when wired up properly

permanent (from common of switch)
switched (from live at downlight)

kkelly77

maxfresh wrote: »

Take the loop of wire out you will have the two feeds when wired up properly

permanent (from common of switch)
switched (from live at downlight)

That's actually how I had it wired up earlier when I first posted and it wasn't working. Possibly the transformer for the lights is stepping down the voltage too much?

meercat

kkelly77 wrote: »

I've just tried that Meercat and it worked

Does this mean I need the same loop wire setup when I have the fan reinstalled in the attic? Won't that just keep the fan on permanently?

if you connect it like this and join onto the downlight power(230 volt)then the fan will run when lights are turned on
if you want the fan to run after the lights are switched off,then you need a permanent feed from the light switch

this set up does not take into account the isolator(which is a regulation)

meercat

kkelly77 wrote: »

That's actually how I had it wired up earlier when I first posted and it wasn't working. Possibly the transformer for the lights is stepping down the voltage too much?

you need to be on the mains side of the transformer
remember to turn power off before undertaking work

kkelly77

meercat wrote: »

if you connect it like this and join onto the downlight power(230 volt)then the fan will run when lights are turned on
if you want the fan to run after the lights are switched off,then you need a permanent feed from the light switch

this set up does not take into account the isolator(which is a regulation)

I think I know where I might have gone wrong. I need to join onto the downlight power to the L and N of the fan before it gets to the transformer. The cable I have in place on the permanent live side of the light switch will be connected to the Timer connector of the fan as I had originally.

EDIT: And Meercat gets there before I do

meercat

kkelly77 wrote: »

EDIT: And Meercat gets there before I do

think 2011 got there long time ago;)

kkelly77

Got everything wired up today and fan is coming on and off when it should.

Only thing is, it doesn't seem to shift the steam as well as I thought it would. I made sure there were no rips or tears in the flex duct and all connections are secured with cable ties. Is this just down to the unit I purchased?

meercat

have you checked that the extractor is working as it should
turn fan on and place a square of toilet roll over the fan(it should stay in place if extractor is functioning)
check also that the room is not airtight as the extracted air needs to be replaced and not a vacum(gap under door should be sufficient)
in general you may not notice less steam but it should be beneficial

kkelly77

meercat wrote: »

have you checked that the extractor is working as it should
turn fan on and place a square of toilet roll over the fan(it should stay in place if extractor is functioning)
check also that the room is not airtight as the extracted air needs to be replaced and not a vacum(gap under door should be sufficient)
in general you may not notice less steam but it should be beneficial

I didn't use a piece of toilet roll, just put my hand up to it. I could feel the air flow. Now that you mention it, the gap at the bottom of the door is quite tight but is not touching the floor. I am planning to get a piece of rubber to put under the fan itself. It's not noisy when I'm actually in the attic but is very noisy once you're in the bathroom (or elsewhere upstairs).