Fan causing MW RFI

[Jeff Layman]

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?

--

Jeff

[N_Cook]

I find it amazing you can listen to MW/AM in a "modern" house with all
that electronic smog and EMI and RFI everywhere

[Jeff Layman]

Just about everything has a SMPS these days, and often some digital
control. Can't say that I've ever had a problem with any of these before.

Anyway, is there a more nostalgic way to listen to 60s hits than on a MW
portable with a tiny speaker?!

--

Jeff

[N_Cook]

How about one of these for nostalgia and low-fi
https://www.flickr.com/photos/nhwilber/4701108988/
I repaired one a year or more ago, the owner is supposed to be in the UK
and collecting it later this week.
Pioneer must be embarassed , its first domestic product.
Hardboard deck and no electonics , relied on the old telephone carbon
granules principle to feed a speaker, seriously tinny and tiny

[Jeroni Paul]

I find most switching supplies sound through MW and LW only when the radio is one meter or less near. Further than that they have little effect.

[David Platt]

I would certainly try a noise filter at the mains connection. This
would block conducted EMI pretty effectively, which is likely the path
through which the noise is getting out of the fan unit.

Corcom (TE Connectivity) and other companies make modular filter
"cans" which might help a lot. They have various combinations of
shunt C, and series L (wired up for common-mode and differential-mode
suppression), with different amperage ratings and different sorts of
termination.

A Corcom model 3VW1 might be the sort of thing you're looking for... 3
ampere limit (up to 250 VAC), has both common-mode and differential-
mode inductive filters, "effective to control emissions in equipment
using SCR and TTL circuits for compliance with FCC Part 15, Subpart J
and EN55022, Level A, down to 150 kHz."

This "can" model has .25"/6.3mm spade-lug terminals for the line and
load side... Corcom does make some which have wire-lead terminals but
none in the W series, unfortunately.

If the fan is hard-wired to the mains (you didn't say) then installing
a module of this sort in the junction box would be the way to go. If
it's a plug-in to a mains outlet, then you'd need to build some sort
of goes-in-between box or a "filtering jumper cable".

There are quite a few other manufacturers of similar sealed EMI filter
modules... Corcom is just the best-known-to-me.

These sorts of filters are commonly available through surplus channels
(online dealers, ham-radio flea-market sales, etc.) as well as through
distributors such as Mouser and Digi-Key.

[Tom Miller]

"Jeff Layman" <JMLa...@invalid.invalid> wrote in message
news:m4v9va$2qt$1...@news.albasani.net...

You might try winding the AC lines through a ferrite RFI core like the ones
found on switching power modules. Some can be clamped around the wires. You
will want to get all three leads through the core, L, N, and Ground. Maybe
even do a couple of turns if the core is large enough.

[Phil Allison]

** The instructions say all units must be earthed - is yours?

You could try a suppression cap across the line( active to neutral) at the terminal block - close as possible to the fan itself. A class X1 or X2 film cap of about 470nF is a good place to start. But I bet there is one inside the fan already.

I expect the fan motor is a BLDC type, possibly operating at mains voltage, and the pitch of the noise on AM would vary with its speed.


BTW:

Are you living far from AM transmission sites - say than 50 kms ??

BTW 2:

Are you living in a metal clad ( aluminium sided ) building ?

Either of the above means the AM signals inside your home will be very weak.


.... Phil

[hrho...@sbcglobal.net]

Does the interference show up when you use a battery operated radio? That will give you some idea as to whether the interference is conducted or radiated, or, maybe both.

[Phil Allison]

hrho...@sbcglobal.net wrote:

> Does the interference show up when you use a battery operated radio?

** Try reading the OP.

> That will give you some idea as to whether the interference is conducted or radiated, or, maybe both.

** Huh?

Conducted interference ends up radiating via the AC supply wiring.



... Phil

[gregz]

My furnace fan creates so much noise, I can't do much with it on. It's
variable speed, and has peak noise at max speed. I tried some filtering on
ac and thermostat, but it's a big problem.

Greg

[Jeff Layman]

On 25/11/2014 02:10, Phil Allison wrote:
>
> 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?
>
>
> ** The instructions say all units must be earthed - is yours?

I hope so! It was installed by a pro electrician and I have a NICEIC
certificate which says so (http://niceic.com/). But I'll check it anyway.

> You could try a suppression cap across the line( active to neutral)
> at the terminal block - close as possible to the fan itself. A class
> X1 or X2 film cap of about 470nF is a good place to start. But I bet
> there is one inside the fan already.

The only thing I can get in the next day or so is this delta suppression
filter:
http://www.maplin.co.uk/p/delta-suppression-filter-rg21x

> I expect the fan motor is a BLDC type, possibly operating at mains
> voltage, and the pitch of the noise on AM would vary with its speed.

Guess so. The fan often turns in the reverse direction for a second or
so when switched on, then corrects itself.

> BTW:
>
> Are you living far from AM transmission sites - say than 50 kms ??

No. The 999kHz local radio transmitter (1kW) is about 15 km away..

> BTW 2:
>
> Are you living in a metal clad ( aluminium sided ) building ?

The fan is in a new metal-framed conservatory. The mains-powered MW
receiver in the conservatory is completely swamped by the interference.
But the portable radio is outside, maybe 6 metres from the fan, and that
has the interference superimposed on the station I am listening to. It's
no doubt attenuating the interference, but not enough

> Either of the above means the AM signals inside your home will be
> very weak.
>
>

> ..... Phil

Thanks for the info and suggestions.

--

Jeff

[Jeff Layman]

I'll try that. Thanks.

--

Jeff

[Phil Allison]

Jeff Layman wrote:

>
> The only thing I can get in the next day or so is this delta suppression
> filter:
> http://www.maplin.co.uk/p/delta-suppression-filter-rg21x

** That should do OK.

>
> > I expect the fan motor is a BLDC type, possibly operating at mains
> > voltage, and the pitch of the noise on AM would vary with its speed.
>
> Guess so. The fan often turns in the reverse direction for a second or
> so when switched on, then corrects itself.

** Really ?

What makes you sure it is a DC motor ?

DBDC motors are really AC motors with in-built electronic drives.

Motors that power ceiling fans are normally multi-pole induction types - fully reversible.

> No. The 999kHz local radio transmitter (1kW) is about 15 km away..

** So the available signal is weak.

> The fan is in a new metal-framed conservatory.

** So the signal inside is very weak.


... Phil

[Jeff Layman]

On 26/11/2014 01:22, Phil Allison wrote:
> Jeff Layman wrote:
>>

>>> I expect the fan motor is a BLDC type, possibly operating at mains
>>> voltage, and the pitch of the noise on AM would vary with its speed.
>>
>> Guess so. The fan often turns in the reverse direction for a second or
>> so when switched on, then corrects itself.
>
> ** Really ?
>
> What makes you sure it is a DC motor ?

See under "Energy efficiency" on page 3 here:
http://www.fantasiaceilingfans.com/content/pdf/fantasia-brochure-2014.pdf

Also see top of page 2 and section 3 on page 10 here:
http://www.fantasiaceilingfans.com/content/pdf/tau-manual.pdf

> DBDC motors are really AC motors with in-built electronic drives.
>
> Motors that power ceiling fans are normally multi-pole induction types - fully reversible.

So it could be that the manufacturer calling it a "DC motor" is being a
bit flexible with the definition?

>> No. The 999kHz local radio transmitter (1kW) is about 15 km away..
>
> ** So the available signal is weak.

Fairly so, but reception is quite acceptable when the fan is off.

>> The fan is in a new metal-framed conservatory.
>
> ** So the signal inside is very weak.

Indeed, even with a loop aerial connected.

--

Jeff

[Phil Allison]

Jeff Layman wrote:

> > ** Really ?
> > What makes you sure it is a DC motor ?
>
> See under "Energy efficiency" on page 3 here:
> http://www.fantasiaceilingfans.com/content/pdf/fantasia-brochure-2014.pdf

** So my original hunch was correct.

Some modern ceiling fans use low voltage( ie 24V) BLDC motors operating from a SMPS - all crammed into the same housing.

Why one would run in the wrong direction before correcting itself is a tad mysterious.

>
> >> No. The 999kHz local radio transmitter (1kW) is about 15 km away..
> >
> > ** So the available signal is weak.
>
> Fairly so, but reception is quite acceptable when the fan is off.

** You have missed the point.

>
> >> The fan is in a new metal-framed conservatory.
> >
> > ** So the signal inside is very weak.
>
> Indeed, even with a loop aerial connected.

** Assuming the fan has not developed a fault since you installed it, the RFI you are hearing may well be within legal limits for such appliances.

The AM and HF (short wave) bands do not enjoy the same regulatory protection as FM and TV reception does - so things like SMPSs and motor drives are permitted interfere somewhat with AM receivers in the same premises.

Having only weak signals available in the vicinity makes it so much worse.

Is the fan motor in a plastic enclosure ?

A grounded, metal one would be far better at supressing AM band noise.


.... Phil





>
> --
>
> Jeff

[Jeff Layman]

On 26/11/2014 11:15, Phil Allison wrote:
> Jeff Layman wrote:
>

> Some modern ceiling fans use low voltage( ie 24V) BLDC motors
> operating from a SMPS - all crammed into the same housing.
>
> Why one would run in the wrong direction before correcting itself is
> a tad mysterious.

Puzzled me too so I Googled for the explanation. I have no idea if it is
accurate, but see the final paragraph in this section:
https://en.wikipedia.org/wiki/Brushless_DC_electric_motor#Controller_implementations

>>>> No. The 999kHz local radio transmitter (1kW) is about 15 km
>>>> away..
>>>
>>> ** So the available signal is weak.
>>
>> Fairly so, but reception is quite acceptable when the fan is off.
>
>
> ** You have missed the point.
>
>>
>>>> The fan is in a new metal-framed conservatory.
>>>
>>> ** So the signal inside is very weak.
>>
>> Indeed, even with a loop aerial connected.
>
>
> ** Assuming the fan has not developed a fault since you installed it,
> the RFI you are hearing may well be within legal limits for such
> appliances.
>
> The AM and HF (short wave) bands do not enjoy the same regulatory
> protection as FM and TV reception does - so things like SMPSs and
> motor drives are permitted interfere somewhat with AM receivers in
> the same premises.

I don't know if it is. It should fall within Directive 2004/108/EC, but
it isn't CE marked, and compliance with that Directive isn't mentioned
in the manual.

>
> Having only weak signals available in the vicinity makes it so much
> worse.
>
> Is the fan motor in a plastic enclosure ?
>
> A grounded, metal one would be far better at supressing AM band
> noise.

I think it is plastic.

Anyway, I was able to try a few things today, and the interference has
been reduced to almost zero. Firstly, the earth appears OK. Just in
case, I connected another earth lead to a known good earth, but it made
no difference. Next I fitted the delta filter, which suppressed the
interference almost completely - result! Next I pulled the power
connector plug apart and wound the lead a couple of times through a
large ferrite ring (the only one I could get easily), and that cut out
almost completely what little noise was left. There is slight
interference when the fan is running at full speed, but I never use it
at that. speed.

So that's a good result without dismantling and returning the fan - thanks.

But here's something odd I found on the way. I got the MW on the
mains-wired radio in the conservatory working pretty well with only a
metre of wire connected as an aerial. It wasn't bad, but a bit quiet.
Well, the signal was weak. Fair enough in the metal conservatory. But
that was with the fan power connector unplugged (for fitting the ferrite
ring). As soon as put the power connector back together, so I could run
the fan (this is with the main power still disconnected at the wall
switch), the radio reception improved tremendously - loud and clear!
When I pulled the connector it went back to fairly quiet again. Weird -
something is acting as an aerial, but how?

--

Jeff

[junebug1701]

The nerve of them to put Hawaii on the box, after what they did to Pearl Harbor!

[johnso...@gmail.com]

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.
>

try a few turns on a fairite core on the power leads at the device
type 75 are only about a $1 , I put them on everything in my home
ko6kL.... more on my qrz.com page.

[Jeff Layman]

Looks like Google Groups is doing funny things again. Your reply is to a
post I made over 5 years ago!
<https://groups.google.com/forum/#!topic/sci.electronics.repair/zNoZd7n4SeI>

--

Jeff

[bruce bowser]

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 ...)

[Cydrome Leader]

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.

[Jeff Layman]

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.

--

Jeff

[Cydrome Leader]

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

[Jeff Layman]

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

--

Jeff

[amdx]

  I had a outdoor IR light that radiated from the light into the house.
I could follow the electrical line

using my AM radio all the way to the circuit breaker panel. This became
a problem when I installed an

active antenna about 50ft from the light. My fix was to install a Corcom
line filter near the light, The Corcom

line filter may or may not have been over kill, but, it was in my junk
box, so I used it. It did the job.

 After a house rebuild (hurricane) we installed 5 new outdoor light, I
bought two different models at Lowes.

brought them home and tested them with my AM radio, I picked the quiet
one and bought 4 more for the house.

Mikek


--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

[John Robertson]

On 2014/11/24 4:57 a.m., 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?
>

Some ferrite clamp-on filters might help if you can get at the power
lines close to the source...

If the junction box has enough room install a sheilded RFI filter like this:

https://www.digikey.ca/en/products/filter/power-line-filter-modules/838

Select for current, voltage, etc and you will see suitable units
starting around 10USD. I don't know your lines voltage or frequency so
that too you have to plug in...

John :-#)#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

[Brad Johnson]

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

you can try and put a AC line filter as close to the device as you can , 3 wire AC feeding is better ....
DC motor may need bypass caps , which might be a problem for the 6-speed driver....
The clamp on fairrite or a core should be on everything in a ham home, and all overhead AC drop lines IMO.
the type 75 cores are only about $1 and go after all the noise below 1mhz ( that's is where most of it comes from )
you may be able to use the AC line filters on DC if amp rating is enough ( leave a little margin here... )
tips from a solar-powered ham radio operator.
pics on my QRZ site Ko6kL

[Jeff Layman]

LOL!

I posted the original query almost 9 years ago! It was fixed a few days
later by using a delta suppression capacitor and ferrite ring large
enough to take all the mains leads.

--

Jeff