I purchased a “quiet” ceiling fan just over a year ago for fitting in a bathroom ceiling over a shower area.
There is no problem with the flow performance and reliability of the fan which is wired up off a zoned lighting circuit with the normal switched and direct 220 volt supply – the latter for the run-on period. The fan is ganged/switched in parallel with low voltage ceiling halogen lights which have their own mini-transformers off the switched supply. Our electrical supply is off a local pole transformer with a separate supplier earth rod grounding at the meter/connection area backed up by a connected additional earth rod installed within the house.
The fan runs quietly, with a very faint electrical “hum”, but after the light/fan is switched off the running-on fan often develops an increasingly noisy electric hum - some times with slight “hunting”. This noise often does not occur during daytime. When this noise occurs it normally continues until the time out stops the fan, but it has been known to stop before the time out period expires and the fan stops. The noise always occurs and is very worse during night time use, i.e. when there is no other or little other power demand on the house circuits.
I am at a loss in trying to understand the cause of the noise which, from the above, seems to be limited to the run-on period. Is it related to over-voltage power supply at night during periods of low power demand at the end of a locally stepped down supply? Is it somehow earthing or phase related? Is it related to the inductive nature of the fan power load as operated and fed through your run-on system within the fan? Or is it simply a fault in the fan?
Any advice you could provide would be appreciated.
There is no problem with the flow performance and reliability of the fan which is wired up off a zoned lighting circuit with the normal switched and direct 220 volt supply – the latter for the run-on period. The fan is ganged/switched in parallel with low voltage ceiling halogen lights which have their own mini-transformers off the switched supply. Our electrical supply is off a local pole transformer with a separate supplier earth rod grounding at the meter/connection area backed up by a connected additional earth rod installed within the house.
The fan runs quietly, with a very faint electrical “hum”, but after the light/fan is switched off the running-on fan often develops an increasingly noisy electric hum - some times with slight “hunting”. This noise often does not occur during daytime. When this noise occurs it normally continues until the time out stops the fan, but it has been known to stop before the time out period expires and the fan stops. The noise always occurs and is very worse during night time use, i.e. when there is no other or little other power demand on the house circuits.
I am at a loss in trying to understand the cause of the noise which, from the above, seems to be limited to the run-on period. Is it related to over-voltage power supply at night during periods of low power demand at the end of a locally stepped down supply? Is it somehow earthing or phase related? Is it related to the inductive nature of the fan power load as operated and fed through your run-on system within the fan? Or is it simply a fault in the fan?
Any advice you could provide would be appreciated.