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ceiling fan speed control

F

Fritz Oppliger

I installed a pleasantaire brand fan in my kitchen. It runs rather fast,
the calendar wants to leap off the wall.
It has a four wire connection, it is made to be reversible.
White and Black always neutral and hot.
Blue and Red join neutral and hot respectively but are reversed to change
direction.

I tried halving the power (?) by inserting a 4006 diode into the hot
supply.
I have seen this trick with other "adjustable" appliances .
That slowed it down too much.. it barely moves and hums loudly.
So before I cause the thing to burn up I figure I'd ask... what is the
bestest way to tame this hurricane?
Thanks in advance
Fritz
 
J

John Popelish

Fritz said:
I installed a pleasantaire brand fan in my kitchen. It runs rather fast,
the calendar wants to leap off the wall.
It has a four wire connection, it is made to be reversible.
White and Black always neutral and hot.
Blue and Red join neutral and hot respectively but are reversed to change
direction.

I tried halving the power (?) by inserting a 4006 diode into the hot
supply.
I have seen this trick with other "adjustable" appliances .
That slowed it down too much.. it barely moves and hums loudly.
So before I cause the thing to burn up I figure I'd ask... what is the
bestest way to tame this hurricane?
Thanks in advance

This fan is a strictly AC operation. You may be able to slow it
without overheating it by lowering the applied voltage. An old
fashioned fluorescent lamp ballast inductor (the kind you use with a
starter device) and available at many hardware and electrical supply
stores) may work. Or you might use a step down transformer or
autotransformer. Do you have access to a variac (variable
autotransformer) that you could experiment with to find if this
solution is functional? If not, you might just wire a lamp socket in
series and experiment with different wattage lamps as a means of
temporarily reducing the voltage. After you know the voltage needed,
and the current the motor draws at that voltage, you are in a much
better position to select a means of supplying that voltage.
 
B

bj

John Popelish wrote
This fan is a strictly AC operation. You may be able to slow it
without overheating it by lowering the applied voltage. An old
fashioned fluorescent lamp ballast inductor (the kind you use with a
starter device) and available at many hardware and electrical supply
stores) may work. Or you might use a step down transformer or
autotransformer. Do you have access to a variac (variable
autotransformer) that you could experiment with to find if this
solution is functional? If not, you might just wire a lamp socket in
series and experiment with different wattage lamps as a means of
temporarily reducing the voltage. After you know the voltage needed,
and the current the motor draws at that voltage, you are in a much
better position to select a means of supplying that voltage.

Hi
What's wrong with using a light dimmer switch-without all the
messing
about above-and you get total controll?
Several years ago a friend of mine had a similar problem with a chimney
extractor fan and I got him a dimmer switch and it's been working for
5+years. Seem to remember that there was a problem with dimmer switches
and inductive loads and/or current consumption but I'm sure you can get one
that will do the job

BJ
 
M

Michael A. Terrell

bj said:
Hi
What's wrong with using a light dimmer switch-without all the messing
about above-and you get total control?
Several years ago a friend of mine had a similar problem with a chimney
extractor fan and I got him a dimmer switch and it's been working for
5+years. Seem to remember that there was a problem with dimmer switches
and inductive loads and/or current consumption but I'm sure you can get one
that will do the job

BJ

There are speed controls for ceiling fans. They are not made as light
dimmers, even though they may look like one. Any place that sells the
ceiling fans should have the controls. The chimney extractor fan your
friend had may have been a "Universal", or in other words, used brushes
and didn't care if it ran on AC, or DC pulses.
 
B

bj

Michael A. Terrell said:
There are speed controls for ceiling fans. They are not made as light
dimmers, even though they may look like one. Any place that sells the
ceiling fans should have the controls. The chimney extractor fan your
friend had may have been a "Universal", or in other words, used brushes
and didn't care if it ran on AC, or DC pulses.

--
We now return you to our normally scheduled programming.

Michael A. Terrell
Central Florida

Hi
It was that bit at the bottom that prompted this post

you're quite right that the motor my friend has is brushed and I don't
really
have a clue how modern motors work.However I just dug out my 1977
electronics book and I see (from the phase angle waveforms for a
triac) that with a little bit of smoothing, your normal
dimmer switch could maybe controll one of these motors
Any ideas?

BJ
 
J

JeB

I tried halving the power (?) by inserting a 4006 diode into the hot
supply.
I have seen this trick with other "adjustable" appliances .
That slowed it down too much.. it barely moves and hums loudly.
So before I cause the thing to burn up I figure I'd ask... what is the
bestest way to tame this hurricane?

I've got the type of dimmer promoted as a motor speed controller. Starts
at highest output after switched on vs lowest of a dimmer. With my
fan/controller combo there's loud ac hum once you get below about 2/3
speed and before hitting about 1/3 speed. (ie ... hum at mid speeds). I
just use one side or the other of hum and still find it useful. Don't
recall where I bought it but probably an online electronics outfit. I
suppose a normal dimmer might work as well ... i don't know that the
motor controller does anything different as far as waveform. And I'd
imagine the manufacturer offers some sort of speed control too ... but
likely expensive.

(Wouldn't an approach that chopped up the waveform more be less likely
to cause hum? or it might just be higher frequency)
 
J

John Popelish

bj said:
Hi
What's wrong with using a light dimmer switch-without all the
messing
about above-and you get total controll?
Several years ago a friend of mine had a similar problem with a chimney
extractor fan and I got him a dimmer switch and it's been working for
5+years. Seem to remember that there was a problem with dimmer switches
and inductive loads and/or current consumption but I'm sure you can get one
that will do the job
It might work, but since dimmers are made specifically to control
resistive loads and ceiling fans are very low power factor motors
(very inductive loads) there can be all sorts of problems with dimmer
control from producing DC output (which will quickly burn the motor
up) to jumping from very low speed to full speed (losing control).
These problems are all addressable, but I didn't want to suggest
method that was problematic to a beginner.
 
D

Dan Akers

Fritz wrote;
"I have seen this trick with other "adjustable" appliances . That slowed
it down too much.. it barely moves and hums loudly. So before I cause
the thing to burn up I figure I'd ask... what is the bestest way to tame
this hurricane?"
______________________________________
Re;
For U.S., 120V/60Hz ceiling fans, the typical scheme for speed control
is a four-position, pull-chain switch on the units I've tinkered with.
The switch positions are "off", "L to 1", "L to 1&2", and "L to 3",
where "L" is the line side voltage input. The motors are capacitor run
devices; meaning they have two coils; in switch pos. #3 (hi speed) one
winding is tied directly across the line supply and the other tied in
the same fashion EXCEPT there is a 4 to 6 uF run cap. in series to
accomplish the necessary phase displacement for a rotating field. Speed
reduction is accomplished with two other capacitors; usually 4 and 5uF,
used as "zero power" voltage dropping devices. Thus, in switch position
1, both motor coils are powered through the 4uF series cap; in position
2, the 4 and 5uF cap are paralleled for 9uF total series dropping
capacitance. Note that the run cap above is always in the circuitry,
regardless of speed selected. I'm surprised the motor ran at all with
the series diode!!
In some fans there are two distinct capacitor devices; one, the "motor
run cap" and the other a dual capacitor device in one package for the
series dropping caps. Some even have all three caps in one unitized
package.
Having said all of that, these caps can be purchased at department
stores and hardware stores in the ceiling fan section. So, you might
try installing one of these in series with the motor power supply lead
to reduce the speed.

-Dan Akers
 
M

Mark Monson

JeB said:
I've got the type of dimmer promoted as a motor speed controller. Starts
at highest output after switched on vs lowest of a dimmer. With my
fan/controller combo there's loud ac hum once you get below about 2/3
speed and before hitting about 1/3 speed. (ie ... hum at mid speeds). I
just use one side or the other of hum and still find it useful. Don't
recall where I bought it but probably an online electronics outfit. I
suppose a normal dimmer might work as well ... i don't know that the
motor controller does anything different as far as waveform. And I'd
imagine the manufacturer offers some sort of speed control too ... but
likely expensive.

(Wouldn't an approach that chopped up the waveform more be less likely
to cause hum? or it might just be higher frequency)

There are two types of ceiling fan speed controls. The cheap ones make the
motor hum at reduced speeds. The expensive ones don't. Buy a control made
by Hunter or Casablanca. They work quietly on even cheap fans.

MM
 
F

Fritz Oppliger

There are two types of ceiling fan speed controls. The cheap ones make
the
motor hum at reduced speeds. The expensive ones don't. Buy a control
made
by Hunter or Casablanca. They work quietly on even cheap fans.

MM

And if I add into the mix the fact that is this all running on inverter
power, i.e. modified sinewave / glorified squarewave (take your pick)...
what do I get?
 
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