ceiling fan buzzing
klem kedidelhopper
very slow speed at night. The fan was purchased as new surplus many
years ago and never came with a speed control. So I have been using a
generic solid state speed controller. With this unit we are able to
take the unit down to complete "crawl" however there has always been a
slight rhythmic buzzing noise whose loudness and duty cycle are both
directly proportional to the motor speed. I know it's related to the
pulse type of control I'm using but short of just using a variac or a
rheostat for that matter, does anyone know of a method to achieve a
very slow speed without the noise?
Also this motor has no brushes and so even though its not labeled as
such I wonder if it could be a "Universal" type of motor that could
run on DC? It wouldn't take much to put a bridge and perhaps even a
filter in the electrical box ahead of the motor. I'm thinking that DC
operation could possibly be quieter. Thanks, Lenny
lsmartino
wrote:
A 120vac ceiling fan motor uses a pancake induction motor which can't
be used with DC. I have seen wall rehostats for sale at hardware
stores to be used with ceiling fans. Some of them have two controls,
one for the ceiling fan lamp light and another for the fan. These can
be installed inside a 2x4 box. The ones I have seen are manufactured
by Ace Hardware.
Good luck!
Bennett Price
I wonder if you ran it at full speed without the blades and the
'whoosh' they cause you might still hear the buzz/hum.
Perhaps as an experiment power it off a resistor for a couple of
seconds.
Michael A. Terrell
Is the speed controler made for induction motors?
--
It's easy to think outside the box, when you have a cutting torch.
klem kedidelhopper
wrote:
How would a speed controller made for induction motors differ from say
an ordinary lamp dimmer?
Michael A. Terrell
klem kedidelhopper wrote:
>
> On Jul 16, 7:35 pm, "Michael A. Terrell" <mike.terr...@earthlink.net>
> wrote:
> > klem kedidelhopper wrote:
> >
> > > We have a ceiling fan in our bedroom that we sometimes like to run at
> > > very slow speed at night. The fan was purchased as new surplus many
> > > years ago and never came with a speed control. So I have been using a
> > > generic solid state speed controller. With this unit we are able to
> > > take the unit down to complete "crawl" however there has always been a
> > > slight rhythmic buzzing noise whose loudness and duty cycle are both
> > > directly proportional to the motor speed. I know it's related to the
> > > pulse type of control I'm using but short of just using a variac or a
> > > rheostat for that matter, does anyone know of a method to achieve a
> > > very slow speed without the noise?
> >
> > > Also this motor has no brushes and so even though its not labeled as
> > > such I wonder if it could be a "Universal" type of motor that could
> > > run on DC? It wouldn't take much to put a bridge and perhaps even a
> > > filter in the electrical box ahead of the motor. I'm thinking that DC
> > > operation could possibly be quieter. Thanks, Lenny
> >
> > Is the speed controler made for induction motors?
>
> an ordinary lamp dimmer?
Lamp dimmers are simple phase controllers. They aren't designed for
inductive loads. That's why most light dimmers can't be used on
Florescent lights. They can cause the motor to overheat at some speeds,
and cause it to be noisy or erratic at low speeds.
Leviton makes variable speed fan controls with a slider to set the
speed. You can get them at HD, Lowes or a lot of other building supply
stores.
<http://www.leviton.com/OA_HTML/ibeCCtpSctDspRte.jsp?section=10857&minisite=10025>
klem kedidelhopper
>
> <http://www.lowes.com/SearchCatalogDisplay?Ntt=speed+control&langId=-1...>
>
> <http://www.homedepot.com/webapp/wcs/stores/servlet/Search?keyword=spe...>
> --
> It's easy to think outside the box, when you have a cutting torch.
Thanks Michael for sending me those dimmer links. They are pricey
though... Lenny
klem kedidelhopper
wrote:
I did find the Leviton but it may not be a continuously variable unit.
I'll have to go look at them. Lenny
Paul G.
I had a fan that was noisy like that, and stuck a 5-10 uF capacitor
in series with the motor. You can't use the dimmer - so you need a
switch to hook the fan either to the controller or the series cap. It
runs quite slowly, and no buzzing. Make sure the capacitor is designed
for line use ..... 250vac or 600vdc should be OK. If it fails, the fan
will just run at full speed. The only worry would be if it were to get
hot say from internal arcing or something wierd like that. To be one
the safe side use a U/L approved or type Z capacitor.
You can cause the cap and inductance of the fan to resonate....
That will cause voltages greater than the line voltage to appear
across the fan motor, and it go fast, and overheat. Try a few
capacitors, starting at 1uf, and increase until you get the speed you
want.
Some fans have a switch that gives 3-4 speeds, with a series cap,
you can effectively get a much slower range of speeds, and thereby not
need to use a dimmer type speed controller.
Paul G.
Paul G.
wrote:
That should be a "X" type capacitor, not a "Z" type. It's
questionable that you need either X or Y types.
From an Illinois Capacitor blurb on capacitors:
" These capacitors are divided into 2 classifications, X and Y. X
class capacitors are capacitors that are connected line to line and in
the event of failure of the capacitor the potential for electrical
shock is not present. X capacitors are further subdivided into three
subcategories X1, X2 and X3. X1 capacitors are used where the peak
voltage the capacitors will be greater than 2500 volts and less than
4000V. Class X2 capacitors are in applications where the peak voltage
is equal to below 2500 volts. X3 capacitors are used where the peak
voltage is less than or equal to 1200 volts. X2 capacitors are the
most common.
Y capacitors on the other hand are connected from line to ground. They
are typically a very low capacitance value. In the event a Y capacitor
fails the potential for electrical shock is present. Y capacitors are
also subdivided into four subcategories, Y1, Y2, Y3 and Y4. Y1
capacitors are used with voltages up 500Vac, Y2 are used with voltages
up to 300Vac,Y3 are used with voltages up to 250Vac and Y4 capacitors
are used up to 150Vac.
X class capacitors are rated up to 660Vac and Y capacitors are
manufactured with voltage ratings up to 440Vac.
X class capacitors are manufactured with a variety of dielectric
materials. This includes polyester, polypropylene, ceramic and paper
while Y capacitors are typically produced out of ceramic and paper
dielectrics. With the exception of ceramics the capacitors are
produced using metallized materials and may be impregnated with epoxy
or mineral oils."
klem kedidelhopper
> On Mon, 18 Jul 2011 21:35:26 -0300, Paul G. <paul...@eastlink.ca>
I'm thinking that the fan draws about 1.0 amp. Therefore that current
would be passing through the capacitor. I do have lots of capacitors
as well as a 5 position tapped transformer type speed control from
another fan. The problem with that control though is that slow speed
is not slow enough. Perhaps I could put the capacitor in series with
slow position and see what that will do. I never thought of doing
this. Lenny
Wild_Bill
than one type of AC motors without brushes.
Klem/Lenny hasn't revealed what type of AC motor he's referring to.. nor
anything specific regarding the "generic" controller that wasn't supplied
with the fan.
--
Cheers,
WB
.............
"Paul G." <pau...@eastlink.ca> wrote in message
news:4ak9275fo8vqf5fht...@4ax.com...
>
> I had a fan that was noisy like that, and stuck a 5-10 uF capacitor
> in series with the motor. You can't use the dimmer - so you need a
> switch to hook the fan either to the controller or the series cap. It
> runs quite slowly, and no buzzing. Make sure the capacitor is designed
> for line use ..... 250vac or 600vdc should be OK. If it fails, the fan
> will just run at full speed. The only worry would be if it were to get
> hot say from internal arcing or something wierd like that. To be one
> the safe side use a U/L approved or type Z capacitor.
> You can cause the cap and inductance of the fan to resonate....
> That will cause voltages greater than the line voltage to appear
> across the fan motor, and it go fast, and overheat. Try a few
> capacitors, starting at 1uf, and increase until you get the speed you
> want.
> Some fans have a switch that gives 3-4 speeds, with a series cap,
> you can effectively get a much slower range of speeds, and thereby not
> need to use a dimmer type speed controller.
>
> Paul G.
> On Mon, 18 Jul 2011 06:31:03 -0700 (PDT), klem kedidelhopper
> <captainvi...@gmail.com> wrote:
>
>>On Jul 18, 9:22 am, klem kedidelhopper <captainvideo462...@gmail.com>
>>wrote:
>>>
klem kedidelhopper
> Much depends upon what type of motor is in the ceiling fan. There are more
> than one type of AC motors without brushes.
>
> Klem/Lenny hasn't revealed what type of AC motor he's referring to.. nor
> anything specific regarding the "generic" controller that wasn't supplied
> with the fan.
>
> --
> Cheers,
> WB
> .............
>
>
> news:4ak9275fo8vqf5fht...@4ax.com...
>
>
>
> > I had a fan that was noisy like that, and stuck a 5-10 uF capacitor
> > in series with the motor. You can't use the dimmer - so you need a
> > switch to hook the fan either to the controller or the series cap. It
> > runs quite slowly, and no buzzing. Make sure the capacitor is designed
> > for line use ..... 250vac or 600vdc should be OK. If it fails, the fan
> > will just run at full speed. The only worry would be if it were to get
> > hot say from internal arcing or something wierd like that. To be one
> > the safe side use a U/L approved or type Z capacitor.
> > You can cause the cap and inductance of the fan to resonate....
> > That will cause voltages greater than the line voltage to appear
> > across the fan motor, and it go fast, and overheat. Try a few
> > capacitors, starting at 1uf, and increase until you get the speed you
> > want.
> > Some fans have a switch that gives 3-4 speeds, with a series cap,
> > you can effectively get a much slower range of speeds, and thereby not
> > need to use a dimmer type speed controller.
>
> > Paul G.
> > On Mon, 18 Jul 2011 06:31:03 -0700 (PDT), klem kedidelhopper
> > <captainvideo462...@gmail.com> wrote:
>
> >>On Jul 18, 9:22 am, klem kedidelhopper <captainvideo462...@gmail.com>
> >>wrote:
>
> >>> Thanks Michael for sending me those dimmer links. They are pricey
> >>> though... Lenny
Well I don't really know what kind of a motor this is. I purchased the
fan as new surplus and it never came with a controller. It looks like
my other fans I use in the house but from a different manufacturer.
There are three metal blades, very plain looking "airplane propeller"
style, hangs from the ceiling about 1 foot down. The controller for
the other fans looks like a tapped autoformer with a 5 position
switch. Lenny
KR
Ceiling fans sold in Australia, typically switch between a couple of
non polar mains rated capacitors in series with the motor. a few UF
from memory. can look later at one if you really want to know. (note
here is 50hz, you might need different values for 60hz).
The other type of speed control that is used here - but not as common
is the same as a light dimmer except there is a resistor in series
with the pot to ensure a minimum speed to prevent the motor from
stalling and overheating due to insufficient speed setting for it to
start rotating from a dead stop.
Wolfgang Allinger
On 19 Jul 11 at group /sci/electronics/repair in article
<wb_wi...@XSPAMyahoo.com> (Wild_Bill) wrote:
>Much depends upon what type of motor is in the ceiling fan. There are
>more than one type of AC motors without brushes.
>
>Klem/Lenny hasn't revealed what type of AC motor he's referring to..
>nor anything specific regarding the "generic" controller that wasn't
>supplied with the fan.
Here in PY there are lots of ceiling fans from Wahson/China.
230V/50Hz
They use a separate autotransformer in an aluminium housing (15x9x4 cm)
as controller.
It is in series with the motor and has 7 taps and a turning switch with
weird numbered positions from 0 = off and 1=max ... 7=slowest speed!
The motor so gets between 230V and down to some 80V.
My 5 Wahsons did not buzzing, even in slowest speed.
However I have 2 fans (also made in china) with no external controller
but a small hanging line which switches between 3 different speeds by
taping different positions in the motor winding. They both are buzzing
in speeds below max. I think thats in the remaining active sectors of
the winding.
None of these motors have brushes.
Saludos Wolfgang
--
Meine 7 Sinne:
Unsinn, Schwachsinn, Blödsinn, Wahnsinn, Stumpfsinn, Irrsinn, Lötzinn.
Wolfgang Allinger Paraguay reply Adresse gesetzt !
ca. 15h00..21h00 MEZ SKYPE:wolfgang.allinger
klem kedidelhopper
> On 19 Jul 11 at group /sci/electronics/repair in article
I would like to try the trick with the capacitor in series with the
slowest tap on the speed control however I am a bit unclear as to how
to "size" the capacitor. By "size" I mean that it seems like if the
motor draws one amp for example, (and I will confirm that first), I
will need a capacitor that can handle more than that amount of current
flowing through it. I remember dealing with this sort of thing in
electronics school, but admittedly that was a very long time ago and
I've forgotten how to work this out.
For instance, I have a 4uf 250V AC capacitor that I would like to try.
This part is designed for motor starting. This is a fairly large
capacitor. The control box measures approximately 8" x 6" X 3". Most
of that space is taken up by the switch and transformer. There would
not be room inside for anything this large. Or do I need to use
anything this large? Thanks, Lenny
Wolfgang Allinger
On 23 Jul 11 at group /sci/electronics/repair in article
<captainvi...@gmail.com> (klem kedidelhopper) wrote:
>On Jul 22, 8:44 am, all2...@spambog.com (Wolfgang Allinger) wrote:
>> On 19 Jul 11 at group /sci/electronics/repair in article
>> Here in PY there are lots of ceiling fans from Wahson/China.
>>
>> 230V/50Hz
>>
>> They use a separate autotransformer in an aluminium housing (15x9x4
>> cm) as controller.
>>
>> It is in series with the motor and has 7 taps and a turning switch
>> with weird numbered positions from 0 = off and 1=max ... 7=slowest
>> speed! The motor so gets between 230V and down to some 80V.
>I would like to try the trick with the capacitor in series with the
>slowest tap on the speed control
Try if it works and the Motor starts in this position. If not, it might
become very hot after it stops at a PWR out and return of PWR.
In the worst case, you will see firefigters at your home after you
return from a party :)
klem kedidelhopper
> On 23 Jul 11 at group /sci/electronics/repair in article
klem kedidelhopper
> On 23 Jul 11 at group /sci/electronics/repair in article
Why don't I just burn my house down before I leave for the party. That
way at least there won't be any surprises when I return.....Lenny
Ron D.
The above should give you some ideas of the speed control methods used
for ceiling fans. Most of the infinately variable ones will end up
with noise. Changing the caps will get you a lower speed. Notice
that there are different methods and not one size fits all. Also at
www.ceilingfanparts.com the spped switches are quite pecular.
KR
wrote:
Took a look inside a controller today, they have 1.8UF and 3.6UF (at
50hz) capacitors (motor was labelled 65w)
Another thing you could to, if you have access to someone who is
reasonably accurate in metal folding, is to fold the fan
blades down a little bit more to change the pitch. (alternately you
might try packing washers between the blade and the motor under the
mounting screws to tilt it slightly more - dont know if it would work
but worth a try)
A friend found that out the hard way years back when unknowingly put 4
blades meant
for a 3 blade fan onto a 4 blade fan body and nearly drove himself mad
trying to work out why he couldnt get it to go fast enough.
He had picked up several fans and a box of blades free from a place
that was being renovated and just picked out 4 blades that looked the
same.
It was a very small difference in blade angle, but knocked off an
enormous amount of speed
klem kedidelhopper
But wouldn't that also load the motor more than it should be? Lenny
KR
definitely would, but whether or not it damages the motor is another
matter.
as long as there is enough airflow around it to not let it overheat it
should be ok ?.
Anon
"klem kedidelhopper" <captainvi...@gmail.com> wrote in message
news:7a03555c-40f1-4dad...@c41g2000yqm.googlegroups.com...
Klem,
First off, remove the light dimmer from the circuit. Dimmers are known to
cause hum/buzzing in ceiling fan induction motors. Ceiling fan induction
motors like sine waves. If the fan still buzzes on pure sine wave AC
current, the motor has loose/separated stator laminations or loose winding
coils on the stator; this is usually not repairable, although a good lacquer
bath could theoretically tighten it up.
The older spinner fans (especially ones that do not have a pull chain switch
to proivde the lower speeds) used a multiple tapped transformer to provide
the lower voltages. It was often too large to fit within a standard wall
switch box and was designed for surface mounting on the wall.
There are controls made specifically for ceiling fans that are incremental
(not continuously variable) that provide reduced voltages for the lower
speeds but keep the sine wave intact. Transformers are no longer used.
Using a capacitor inline with the power to provide the lower speeds is the
preferred method in fan manufacturing today. Today's fans and fan controls
use a dual stage capacitor - paired together in parallel for Medium and one
stage for Low Speed. For 120VAC 60Hz, the capacitor's rated voltage should
be at least 240VAC for the speed control capacitors. Speed capacitor values
range from 1.5�F to 12�F, with the most common falling between 3� and 5�.
There should be a running capacitor wired to one end of one motor winding,
probably mounted above the motor. The �F value of this capacitor is a good
starting point for low speed from speed control capacitors.
Many "universal" ceiling fan controls use 5�F + 5�F or 5�F + 6�F dual
capacitors. This is around 2.5�F for Medium and 5�F or 6�F for Low Speed.
Slowing the motor beyond the natural Low Speed range, to a "crawl" as it
were, with a large capacitor value will likely produce some harmonic noise
anyway, but should not buzz.
The numbering sequence for fan controls always starts at 1 for High Speed
because fans should always be started on High Speed then lowered to the
desired speed. (At a dead stop, the motor is an effective, coupled
inductor, add the speed capacitors and running capacitor, and it can create
voltages in the circuit higher than component ratings.)
Hope this helps
Scott
Dunedin, FL
klem kedidelhopper
> "klem kedidelhopper" <captainvideo462...@gmail.com> wrote in message
> There should be a running capacitor wired to one end of one motor winding,
> starting point for low speed from speed control capacitors.
>
> capacitors. This is around 2.5µF for Medium and 5µF or 6µF for Low Speed.
> Slowing the motor beyond the natural Low Speed range, to a "crawl" as it
> were, with a large capacitor value will likely produce some harmonic noise
> anyway, but should not buzz.
>
> The numbering sequence for fan controls always starts at 1 for High Speed
> because fans should always be started on High Speed then lowered to the
> desired speed. (At a dead stop, the motor is an effective, coupled
> inductor, add the speed capacitors and running capacitor, and it can create
> voltages in the circuit higher than component ratings.)
>
> Hope this helps
> Scott
> Dunedin, FL
Thank you very much for the explanation Scott. That explains a great
many things. My speed controls on these fans are the large tapped
transformers exactly as you described. But now what about the current
flowing through the capacitor? Is this a concern when selecting a
capacitor for the application? Lenny
Anon
> There should be a running capacitor wired to one end of one motor winding,
> starting point for low speed from speed control capacitors.
>
> capacitors. This is around 2.5�F for Medium and 5�F or 6�F for Low Speed.
> Slowing the motor beyond the natural Low Speed range, to a "crawl" as it
> were, with a large capacitor value will likely produce some harmonic noise
> anyway, but should not buzz.
>
> The numbering sequence for fan controls always starts at 1 for High Speed
> because fans should always be started on High Speed then lowered to the
> desired speed. (At a dead stop, the motor is an effective, coupled
> inductor, add the speed capacitors and running capacitor, and it can
> create
> voltages in the circuit higher than component ratings.)
>
> Hope this helps
> Scott
> Dunedin, FL
Thank you very much for the explanation Scott. That explains a great
many things. My speed controls on these fans are the large tapped
transformers exactly as you described. But now what about the current
flowing through the capacitor? Is this a concern when selecting a
capacitor for the application? Lenny
Klem,
Typically ceiling fan motors pull less than 1 amp current at 120V and the
capacitors used in ceiling fans are large, metallized poly film type AC
capacitors. We've never had to consider the current with these capacitors.
Scott