Home |
Search |
Today's Posts |
|
Home Repair (alt.home.repair) For all homeowners and DIYers with many experienced tradesmen. Solve your toughest home fix-it problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
Posted to alt.home.repair
|
|||
|
|||
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 |
#2
Posted to alt.home.repair
|
|||
|
|||
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 |
#3
Posted to alt.home.repair
|
|||
|
|||
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. |
#4
Posted to alt.home.repair
|
|||
|
|||
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. |
#5
Posted to alt.home.repair
|
|||
|
|||
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. |
#6
Posted to alt.home.repair
|
|||
|
|||
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. |
#7
Posted to alt.home.repair
|
|||
|
|||
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. |
#8
Posted to alt.home.repair
|
|||
|
|||
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. |
#9
Posted to alt.home.repair
|
|||
|
|||
Fan motor capactitor use.
|
#10
Posted to alt.home.repair
|
|||
|
|||
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. |
#11
Posted to alt.home.repair
|
|||
|
|||
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. |
#12
Posted to alt.home.repair
|
|||
|
|||
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. |
#13
Posted to alt.home.repair
|
|||
|
|||
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 |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Motor Fan - Not Fan Motor - Sigh! | Metalworking | |||
Has anyone ever replaced their conventional furnace fan motor with anECM motor? | Home Repair | |||
Has anyone ever replaced their conventional furnace fan motor with anECM motor? | Home Ownership | |||
How does a generator and a fan motor 'pulser' control a dc motor? | Metalworking | |||
Whole house fan, attic fan, no fan both fans? | Home Repair |