[Amps] Muffin Fans and hot exhaust

[2]

>
>There has to be some kind of start winding in any single phase motor.
>It may be a shorted turn in a shaded pole motor ( small motor) or an high 
>value inductive winding for larger ones (which may stay on at all times or 
>disconnected after motor starts to turn). But for high torque situations 
>you use a capacitor in series with a lower inductance start winding to get 
>the  motor started. The winding is used to determine the direction of 
>rotation. Other wise the motor may start to rotate in either direction if 
>at all. 

Semi-agreed.  In my mind, on a 4-wire AC motor, an unswitched winding 
that is always in series with a 1 - 8 uF capacitor is a run-winding.  
>
>73
>Bill wa4lav
>
>-----Original Message-----
>From: 2 <2@vc.net>
>To: <W8JI@contesting.com>, "'kb9cry@attbi.com'" <kb9cry@attbi.com>, "Pete 
>Smith	" <n4zr@contesting.com>, "Steve Katz" <stevek@jmr.com>
>Date: Mon, 22 Jul 2002 19:23:47 -0700 
>Subject: RE: [Amps] Muffin Fans and hot exhaust
>
>
>
>>
>>>  [Steve Katz]  I realize that this works to some extent; however, I
>>> have been unsuccessful in quantifying actual results because the AC
>>> motors run on reduced voltage have a great reduction in torque and
>>> thus cannot spin well against back pressure.  When I run a standard
>>> 240V 125cm (4.25") "Boxer" type fan on 120V, I can stall it with the
>>> tip of my finger very easily, no damage done to finger.  
>>
>>Assuming the motor can take it, motors with start/run windings can be 
>>damaged when operated at low voltage, ...
>
>Start-winding motors are used in compressors, where the motor needs to be 
>able to start against static gas pressure.  I have never seen a blower or 
>fan with a start-winding. 
>
>-  R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K, 
>www.vcnet.com/measures.  
>end
>
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-  R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K, 
www.vcnet.com/measures.  
end