Hi
We're replacing a bathroom extractor fan. The old fan was cosmetically damaged and unfortunately got taken out (wife!) without me being able to label the wires.
New fan has a run-on function (timer and a humidistat) and it's totally doing my nut trying to get it to work properly! Please help before I have a breakdown!
The existing wiring from the old fan is 3-core and earth (colours are blue, red and greeny-yellow plus unsleeved earth). There's a normal pull switch for the light and an isolator for the fan and another for the light. The property was built in about 2002.
If I wire up the new fan one way then it runs normally when the light is switched on but then powers off as soon as I switch off the light.
If I then switch the positions of the two live cables (i.e. red and yellow/green) into the fan then it just runs continuously regardless of what position the light switch is running.
I'm a bit stumped - clearly there is a working switched live (the fan can be controlled by the light switch) and a working permanent live (the fan can run continuously). But why isn't the perm live kicking in when the switch live turns off?
My confusion got worse, in fact, when I tried a multimeter on the cable - neither of the live cables seemed to react at all to the switch being pulled (i.e. both cables showed no resistance across the blue neutral in either switch position). But clearly there is a working switch (the fan (and lights) respond to the switch being pulled).
Please advise - I'm starting to lose my mind!
We're replacing a bathroom extractor fan. The old fan was cosmetically damaged and unfortunately got taken out (wife!) without me being able to label the wires.
New fan has a run-on function (timer and a humidistat) and it's totally doing my nut trying to get it to work properly! Please help before I have a breakdown!
The existing wiring from the old fan is 3-core and earth (colours are blue, red and greeny-yellow plus unsleeved earth). There's a normal pull switch for the light and an isolator for the fan and another for the light. The property was built in about 2002.
If I wire up the new fan one way then it runs normally when the light is switched on but then powers off as soon as I switch off the light.
If I then switch the positions of the two live cables (i.e. red and yellow/green) into the fan then it just runs continuously regardless of what position the light switch is running.
I'm a bit stumped - clearly there is a working switched live (the fan can be controlled by the light switch) and a working permanent live (the fan can run continuously). But why isn't the perm live kicking in when the switch live turns off?
My confusion got worse, in fact, when I tried a multimeter on the cable - neither of the live cables seemed to react at all to the switch being pulled (i.e. both cables showed no resistance across the blue neutral in either switch position). But clearly there is a working switch (the fan (and lights) respond to the switch being pulled).
Please advise - I'm starting to lose my mind!