On 04/04/2021 20:02, Cydrome Leader wrote:
Jeff Layman wrote:
On 03/04/2021 19:34, Cydrome Leader wrote:
bruce bowser wrote:
On Monday, November 24, 2014 at 7:57:17 AM UTC-5, Jeff Layman wrote:
I have a 6-months old Fantasia ceiling fan (mains powered, with 6-speed
reversible dc motor) which is causing a lot of interference on MW. FM
is not affected. The interference is there on forward or reverse
rotation, worsens as the speed is increased,, and appears on portable as
well as mains-powered radios.

I can return it to the supplier for replacement or refund, but it is a
bit of a rigmarole to remove and refit. All the electronics are sealed
in, and the only accessible wiring is to the mains connector. Is there
any point in trying some sort of screening or RFI suppression on the
mains wiring before I take it down?

U need an isolated ground receptacle. Used to combat noise interference with audio and video, it must be supplied by a metal raceway or cable system that is an equipment grounding conductor. Connect it past any panelboards and absolutely do not connect it to the panelboard grounding terminal bar, but to independent 3 x 6 ft. independent copper rods completely driven into the ground.

(As per code NEC 517.16 Use of Isolated Ground Receptacles
"The grounding terminal on the isolated ground receptacle must be connected by an insulated equipment grounding conductor with one or more yellow stripes which is permitted to pass through one or more panelboards without a connection to the panelboard grounding terminal bar as permitted in 408.40 ...)

why would a ceiling fan plug into a receptacle? This suggestion is just
dumb.

There's no harm in trying a filter, but checking the quality of your
grounding also doesn't hurt, make sure neutral and hot are not reversed
etc. It still just sounds like a cheaply made motor drive.

That's the first time I've had an old post resurrected by Google Groups! :-)

My OP was over 6 years ago. FWIW the interference was stopped by using a
delta suppression filter and a ferrite ring.

Ha, missed the dates on this. I wonder if that fan still works.

Yep. It's on almost continuously at low speed to keep the air moving
around and prevent mould growth.

--

Jeff