Re: [MBZ] SOT: 1/20 HP motor Q? (Capacitor Q?)

[Jim Cathey via Mercedes]

>
> So, for the EEs, would this motor start better with a capacitor hooked in
> the circuit, and if so, what size?


There are half a dozen basic motor types, exactly one of which uses a
capacitor.
You haven't identified what, exactly, you have there.  For those that need
a capacitor,
they mostly won't run without it.  For those that do not, there's no place
to put one.

Motors require a rotating magnetic field to start on their own, and the way
in which
this is accomplished IS the motor classification.  Fractional horsepower
fan motors
often use shaded pole construction.  They have wretched starting torque,
which
is irrelevant in a fan, and are not terribly efficient, which is irrelevant
at low power
levels.  They're simple, cheap, and nearly bulletproof.  Unless the
bearings go bad,
or the winding opens up, they just run.

-- Jim
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[MBZ] SOT: 1/20 HP motor Q? (Capacitor Q?)

[Curley McLain via Mercedes]

Hey y'all!

I have a dehumidifier that is frustrating.   Everytime I give up and 
figure it is time to change the motor, it works fine.  Whenever I am 
about to pronounce it cured, the fan motor won't start.   Since I got it 
10-15 yrs ago,  the bearings in the fan motor get tight and the motor 
won't start and won't run.  Last year, I took the motor out a couple 
times to free up the bearings and oil the snot out of it., and once 
tried to change it, but every motor I had ran the wrong direction, so I 
kept running it.   At the start of the humid season, I again took it 
out, oiled it, made sure it is turning freely, and put it back 
together.   I took ot off the humidistat, and ran it a week solid, and 
it runs fine, and is free turning.   The problem comes when I try to let 
it run on the humidistat.  once it has been running, shuts off, the fan 
won't start up again unless I start it by hand.



yeah, I know, I have wasted a lot of time with this POS, but the 
scrounger in me wants to keep it running if I can.


Here is the question.  The symptoms remind me of a furnace blower motor 
with a bad capacitor.  So, for the EEs, would this motor start better 
with a capacitor hooked in the circuit, and if so, what size?


Changing the motor is plain simple, but changing the fan blade will be a 
PITA, so i'm still trying to avoid that.


It only needs to make it a few more months, as the house is for sale.

TIA.

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