Fan motor capactitor use.
 

What is the difference between A/C (air conditioning) fan motors that use a
start capacitor and say a ceiling fan that doesn't. Type slow because I'm
not too bright and getting worse...

--
Tekkie

Fan motor capactitor use.
 

Tekkie® wrote:

What is the difference between A/C (air conditioning) fan motors that use a
start capacitor and say a ceiling fan that doesn't. Type slow because I'm
not too bright and getting worse...


Interesting question. I'm not an expert on this, but I knew just
enough to type out an answer. I was on the right track ( %-)),
but someone explained it better at the link below (so I deleted
what I wrote)! HTH!


https://itstillruns.com/ac-motor-nee...t-6596783.html

Bill

Fan motor capactitor use.
 

On Thursday, July 26, 2018 at 3:48:43 PM UTC-4, Tekkie® wrote:
What is the difference between A/C (air conditioning) fan motors that use a
start capacitor and say a ceiling fan that doesn't. Type slow because I'm
not too bright and getting worse...

--
Tekkie

What makes you sure that it doesn't? Just because it's not separate and
visible, doesn't mean there isn't one inside.

Fan motor capactitor use.
 

On 7/26/18 3:48 PM, Tekkie® wrote:

What is the difference between A/C (air conditioning) fan motors that use a
start capacitor and say a ceiling fan that doesn't. Type slow because I'm
not too bright and getting worse...

Resistance to startup- i.e., overcoming inertia- is the issue.

High in an AC compressor (needs a boost from a capacitor) but low in a
ceiling fan (no capacitor necessary).

Think of it like a morning coffee-jolt...

--
The fastest way to stop a bad guy with a gun is a good guy with a gun.

Fan motor capactitor use.
 

On Thursday, July 26, 2018 at 6:56:03 PM UTC-4, Wade Garrett wrote:
On 7/26/18 3:48 PM, Tekkie® wrote:

What is the difference between A/C (air conditioning) fan motors that use a
start capacitor and say a ceiling fan that doesn't. Type slow because I'm
not too bright and getting worse...

Resistance to startup- i.e., overcoming inertia- is the issue.

High in an AC compressor (needs a boost from a capacitor) but low in a
ceiling fan (no capacitor necessary).

Think of it like a morning coffee-jolt...

--
The fastest way to stop a bad guy with a gun is a good guy with a gun.

AFAIK, they are both AC induction motors and you need a phase shift,
generated somehow, to get them moving.

Fan motor capactitor use.
 

On Thu, 26 Jul 2018 15:48:42 -0400, Tekkie®
wrote:


What is the difference between A/C (air conditioning) fan motors that use a
start capacitor and say a ceiling fan that doesn't. Type slow because I'm
not too bright and getting worse...

We finally get to say "split phase" and be correct. The capacitor
actually does "split" the single phase in conjunction with the start
winding in the motor and it creates a temporary "2 phase" system for a
second until the motor gets out of locked rotor.

Smaller motors may be "shaded pole" that create a magnetic shift in
the motor windings themselves without a capacitor. Usually, if you
look you will see a much larger gauge winding there, maybe only one or
2 turns. That creates the shaded pole.
They are not particularly efficient and they have very low starting
torque but if it is a $12 fan from Walmart, what do you expect?
The other place you see shaded pole motors is in small gear head
motors like you might see on a refrigerator defrost timer. Since the
gear reduction is so great and the load so low, they don't need much
torque.

Fan motor capactitor use.
 

On Thursday, July 26, 2018 at 7:57:46 PM UTC-4, wrote:
On Thu, 26 Jul 2018 15:48:42 -0400, Tekkie®
wrote:


What is the difference between A/C (air conditioning) fan motors that use a
start capacitor and say a ceiling fan that doesn't. Type slow because I'm
not too bright and getting worse...

We finally get to say "split phase" and be correct. The capacitor
actually does "split" the single phase in conjunction with the start
winding in the motor and it creates a temporary "2 phase" system for a
second until the motor gets out of locked rotor.

Smaller motors may be "shaded pole" that create a magnetic shift in
the motor windings themselves without a capacitor. Usually, if you
look you will see a much larger gauge winding there, maybe only one or
2 turns. That creates the shaded pole.
They are not particularly efficient and they have very low starting
torque but if it is a $12 fan from Walmart, what do you expect?
The other place you see shaded pole motors is in small gear head
motors like you might see on a refrigerator defrost timer. Since the
gear reduction is so great and the load so low, they don't need much
torque.

The question remains which of those is in most ceiling fans and does
it use a cap? Looks to me like most are split-phase, in which case
they use a cap and are in the same category as the AC motor.

Fan motor capactitor use.
 

On Thu, 26 Jul 2018 17:15:06 -0700 (PDT), trader_4
wrote:

On Thursday, July 26, 2018 at 7:57:46 PM UTC-4, wrote:
On Thu, 26 Jul 2018 15:48:42 -0400, Tekkie®
wrote:


What is the difference between A/C (air conditioning) fan motors that use a
start capacitor and say a ceiling fan that doesn't. Type slow because I'm
not too bright and getting worse...

We finally get to say "split phase" and be correct. The capacitor
actually does "split" the single phase in conjunction with the start
winding in the motor and it creates a temporary "2 phase" system for a
second until the motor gets out of locked rotor.

Smaller motors may be "shaded pole" that create a magnetic shift in
the motor windings themselves without a capacitor. Usually, if you
look you will see a much larger gauge winding there, maybe only one or
2 turns. That creates the shaded pole.
They are not particularly efficient and they have very low starting
torque but if it is a $12 fan from Walmart, what do you expect?
The other place you see shaded pole motors is in small gear head
motors like you might see on a refrigerator defrost timer. Since the
gear reduction is so great and the load so low, they don't need much
torque.

The question remains which of those is in most ceiling fans and does
it use a cap? Looks to me like most are split-phase, in which case
they use a cap and are in the same category as the AC motor.

A ceiling fan is usually a split phase motor with a start capacitor
but it is not a very big capacitor since they don't need a lot of
torque. The cheapest ones might even have a shaded pole motor and a
top of the line model may have a brushless DC motor.

Fan motor capactitor use.
 

Fan motor capactitor use.
 

On Fri, 27 Jul 2018 16:19:30 -0400, Tekkie®
wrote:

posted for all of us...



On Thu, 26 Jul 2018 17:15:06 -0700 (PDT), trader_4
wrote:

On Thursday, July 26, 2018 at 7:57:46 PM UTC-4, wrote:
On Thu, 26 Jul 2018 15:48:42 -0400, Tekkie®
wrote:


What is the difference between A/C (air conditioning) fan motors that use a
start capacitor and say a ceiling fan that doesn't. Type slow because I'm
not too bright and getting worse...

We finally get to say "split phase" and be correct. The capacitor
actually does "split" the single phase in conjunction with the start
winding in the motor and it creates a temporary "2 phase" system for a
second until the motor gets out of locked rotor.

Smaller motors may be "shaded pole" that create a magnetic shift in
the motor windings themselves without a capacitor. Usually, if you
look you will see a much larger gauge winding there, maybe only one or
2 turns. That creates the shaded pole.
They are not particularly efficient and they have very low starting
torque but if it is a $12 fan from Walmart, what do you expect?
The other place you see shaded pole motors is in small gear head
motors like you might see on a refrigerator defrost timer. Since the
gear reduction is so great and the load so low, they don't need much
torque.

The question remains which of those is in most ceiling fans and does
it use a cap? Looks to me like most are split-phase, in which case
they use a cap and are in the same category as the AC motor.

A ceiling fan is usually a split phase motor with a start capacitor
but it is not a very big capacitor since they don't need a lot of
torque. The cheapest ones might even have a shaded pole motor and a
top of the line model may have a brushless DC motor.

I never knew they had capacitors in them. Of course I didn't do a through
exam of any on a ladder or destruction. I always assumed they were shaded
pole motors.

Leads to the next question: How do they perform different speeds?

They just drop the field voltage and allow the rotor to slip. That is
why some of them "moan". As I said some high end fans now use brush
less DC motors and pulse width controllers.

Fan motor capactitor use.
 

On Friday, July 27, 2018 at 5:45:39 PM UTC-4, wrote:
On Fri, 27 Jul 2018 16:19:30 -0400, Tekkie®
wrote:

posted for all of us...



On Thu, 26 Jul 2018 17:15:06 -0700 (PDT), trader_4
wrote:

On Thursday, July 26, 2018 at 7:57:46 PM UTC-4, wrote:
On Thu, 26 Jul 2018 15:48:42 -0400, Tekkie®
wrote:


What is the difference between A/C (air conditioning) fan motors that use a
start capacitor and say a ceiling fan that doesn't. Type slow because I'm
not too bright and getting worse...

We finally get to say "split phase" and be correct. The capacitor
actually does "split" the single phase in conjunction with the start
winding in the motor and it creates a temporary "2 phase" system for a
second until the motor gets out of locked rotor.

Smaller motors may be "shaded pole" that create a magnetic shift in
the motor windings themselves without a capacitor. Usually, if you
look you will see a much larger gauge winding there, maybe only one or
2 turns. That creates the shaded pole.
They are not particularly efficient and they have very low starting
torque but if it is a $12 fan from Walmart, what do you expect?
The other place you see shaded pole motors is in small gear head
motors like you might see on a refrigerator defrost timer. Since the
gear reduction is so great and the load so low, they don't need much
torque.

The question remains which of those is in most ceiling fans and does
it use a cap? Looks to me like most are split-phase, in which case
they use a cap and are in the same category as the AC motor.

A ceiling fan is usually a split phase motor with a start capacitor
but it is not a very big capacitor since they don't need a lot of
torque. The cheapest ones might even have a shaded pole motor and a
top of the line model may have a brushless DC motor.

I never knew they had capacitors in them. Of course I didn't do a through
exam of any on a ladder or destruction. I always assumed they were shaded
pole motors.

Leads to the next question: How do they perform different speeds?

They just drop the field voltage and allow the rotor to slip. That is
why some of them "moan". As I said some high end fans now use brush
less DC motors and pulse width controllers.

I thought they had different windings with different numbers of poles
in there, using different number of poles to get a 3 speeds.

Fan motor capactitor use.
 

On Fri, 27 Jul 2018 16:12:17 -0700 (PDT), trader_4
wrote:

On Friday, July 27, 2018 at 5:45:39 PM UTC-4, wrote:
On Fri, 27 Jul 2018 16:19:30 -0400, Tekkie®
wrote:

posted for all of us...



On Thu, 26 Jul 2018 17:15:06 -0700 (PDT), trader_4
wrote:

On Thursday, July 26, 2018 at 7:57:46 PM UTC-4, wrote:
On Thu, 26 Jul 2018 15:48:42 -0400, Tekkie®
wrote:


What is the difference between A/C (air conditioning) fan motors that use a
start capacitor and say a ceiling fan that doesn't. Type slow because I'm
not too bright and getting worse...

We finally get to say "split phase" and be correct. The capacitor
actually does "split" the single phase in conjunction with the start
winding in the motor and it creates a temporary "2 phase" system for a
second until the motor gets out of locked rotor.

Smaller motors may be "shaded pole" that create a magnetic shift in
the motor windings themselves without a capacitor. Usually, if you
look you will see a much larger gauge winding there, maybe only one or
2 turns. That creates the shaded pole.
They are not particularly efficient and they have very low starting
torque but if it is a $12 fan from Walmart, what do you expect?
The other place you see shaded pole motors is in small gear head
motors like you might see on a refrigerator defrost timer. Since the
gear reduction is so great and the load so low, they don't need much
torque.

The question remains which of those is in most ceiling fans and does
it use a cap? Looks to me like most are split-phase, in which case
they use a cap and are in the same category as the AC motor.

A ceiling fan is usually a split phase motor with a start capacitor
but it is not a very big capacitor since they don't need a lot of
torque. The cheapest ones might even have a shaded pole motor and a
top of the line model may have a brushless DC motor.

I never knew they had capacitors in them. Of course I didn't do a through
exam of any on a ladder or destruction. I always assumed they were shaded
pole motors.

Leads to the next question: How do they perform different speeds?

They just drop the field voltage and allow the rotor to slip. That is
why some of them "moan". As I said some high end fans now use brush
less DC motors and pulse width controllers.

I thought they had different windings with different numbers of poles
in there, using different number of poles to get a 3 speeds.

I suppose some do but they also have dimmer style controls that just
vary the voltage.
The little plastic desk and pedestal fans do have multiple windings as
far as I know.
Larger fans like air handler blowers do use multiple windings.

Fan motor capactitor use.
 

On 07/27/2018 06:49 PM, wrote:

[snip]

I suppose some do but they also have dimmer style controls that just
vary the voltage.

Varying the voltage is possible, but would be very wasteful.
Dimmer controls vary duty cycle.

The little plastic desk and pedestal fans do have multiple windings as
far as I know.
Larger fans like air handler blowers do use multiple windings.

I know about a the 3-speed (inside fan) motor in the A/C where I used to
live. It has 4 wires, common and one for each speed.

Here, I have a 3-speed ceiling fan control that has only 2 wires.

--
Mark Lloyd
http://notstupid.us/

"I have noticed all my life that many people think they have religion
when they are troubled with dyspepsia." -- R.G. Ingersoll