Extraction fan

[Aerlingus]

I have just changed a controller on a extraction fan unit. Manufacturer is quoting twenty minutes for unit to switch off. I have put the controller into auto and switched fan on. The fan is not switching off. Any ideas anyone?

 

[danzor]

perm live feeding the fan?

 

[Aerlingus]

Ok let me explain a bit better. The extraction fan is situated in a shower room. It is activated when the light is switched on. It has two switches as its activated by two seperate changing rooms. I have changed the controller as I thought it would be the board inside controller. I still have same problem with fan when light is switched off from both changing rooms? The fan is not de-activating when 20 to 35 minutes have elapsed.

 

[jeremy]

a friend of mine used to like Massey Fergusons, but now he has a job in a shower room; he's an ex-tractor fan. SORRY. Try completely disconnecting one of the switches in case they have been wired incorrectly, but it wouldn't be the first fan with a timer that's lost all track of time. Oh and sorry about the ---- "joke" at the start

 

[old dog]

has the fan got an humidistat?

 

[IrishSparks]

Sounds like the perm feed and the switchwire are mixed up in the fan

 

[ian.settle1]

a friend of mine used to like Massey Fergusons, but now he has a job in a shower room; he's an ex-tractor fan. SORRY. Try completely disconnecting one of the switches in case they have been wired incorrectly, but it wouldn't be the first fan with a timer that's lost all track of time. Oh and sorry about the ---- "joke" at the start

For a joke like that you will be taken out at dawn and shot

 

[greekislandlover]

Ok let me explain a bit better. The extraction fan is situated in a shower room. It is activated when the light is switched on. It has two switches as its activated by two seperate changing rooms.

I've had this with fans that service separate bathroom/toilet but are mounted midway between the two rooms. You have to be very careful how they are wired. You may need to have double poled switches to isolate the switched fan live from the light switched return. If you fit single pole, the permanent live can run down one switch, through it, and up the other one creating a permanent live to the fan, but the lights work. Having double poled switches means that the lights will switch as required, and the fan will not be permanently fed .This doesn't make any sense - I've just read it back. But you might need to look very carefully at the manufacturers wiring diagram, as the person before might not have adhered to it.

What I'd be inclined to do is to check that the switched live to the fan is indeed a switched live, and goes off when both lights are out. If that's the case then the wiring is OK, but the fan may be a problem. If the switched live isn't switching, then look at the wiring. If you find that the wiring is not providing the switched fan feed, post back here and I'll do a sketch to explain the rabid ramblings!!

 

[Mike P]

Why don't you rig a tempory feed to it so you control it and not the perm wireing and check that. that would isolate fan or controller.

 

[Aerlingus]

I know see the error of my ways. This sounds like its a faulty switch. As the extraction fan by all accounts has only just started to not de-energise and on inspection was diagnosed as a controller/timer fault. Now it is apparent that the original controller /timer was ok as I think there Is a Permanent Live going to the fan from One of the faulty switches. Does anyone agree?

 

[Mike P]

That sounds right. Has anyone changed a switch or light fitting, reversed the switch and line on the fan or even a nail through a cable shorting switch and line?
Just a thought there is not an intermediade switch wired incorrecly?