Ceiling Fan Noise

Questioner:	Matt
Category:	Electrical Wiring in the Home
Private:	No
Subject:	Ceiling Fan Noise
Question:	"I have a number of ceiling fans with lights (no dimmer switches) throughout my 12 year old double story house. Ever since installing the fans (not all are the same makes or models and some 6 months after the others) they all make the same high pitched pulsating "singing" sound. All the fans do it and all at the SAME TIME (synchronized). The singing noise is quite rhythmical and sounds electrical based (sort of like a UFO hovering sound from a bad sci-fiction movie). The noise only occurs every now and then (normally a few times a day) and is quite loud especially when everybody is asleep. If one fan is turned off whilst the noise is occurring you can still hear the other fans upstairs still "singing". The noise varies in length and can last for up to 30 seconds but normally only goes for around ten to twenty seconds. It's enough to scare our 3 year old at night. Please help."
Answer:	Hi Matt, Wow, that sound annoying. Do you live close to a big antenna? Say a TV station or Radio? That can dot. Large power line close by could do that as well. If not I would have someone install a surge protector on your panel and maybe even a power factor corrector.