On Wednesday, August 26, 2015 at 12:39:07 PM UTC-5, Don Y wrote:
On 8/25/2015 6:15 PM, Ameri-Cleanatsbcglobal wrote:
My daughter has a through-the-wall air conditioner where the blower runs
only on low speed. It cools well and the blower turns freely but it won't
speed up when the control is put on medium or high speed.

So, the blower motor *will* start when the speed is set to "low"?

A friend suggested
the capacitor needs replacing. Is that the likely problem or is there
another possibility? The unit is about 6 years old and appears clean inside.
NOt sure if this is relevant but my daughter says the problem started after
a big storm recently. The model is ajcq10dcdw2. Thanks.

If it is easy to get at AND you are careful (by nature), you can
try to see if you can manually get the fan to spin *backwards*
(though if it does so, it will be very weak).

If the fan seems "strong" (i.e., resists attempts to keep it stalled)
even though slow, don't bother checking.

[It's a small enough fan that this is less likely to be conclusive]

Yes, the fan turns when started but the output is low on all settings. I assume that if the fan is weak the motor is probably shot. If strong it is likely the capacitor. Is that what you are implying?

On 8/26/2015 9:26 PM, wrote:

A friend suggested the capacitor needs replacing. Is that the likely
problem or is there another possibility? The unit is about 6 years old
and appears clean inside. NOt sure if this is relevant but my daughter
says the problem started after a big storm recently. The model is
ajcq10dcdw2. Thanks.

If it is easy to get at AND you are careful (by nature), you can try to
see if you can manually get the fan to spin *backwards* (though if it does
so, it will be very weak).

If the fan seems "strong" (i.e., resists attempts to keep it stalled) even
though slow, don't bother checking.

[It's a small enough fan that this is less likely to be conclusive]

Yes, the fan turns when started but the output is low on all settings. I
assume that if the fan is weak the motor is probably shot. If strong it is
likely the capacitor. Is that what you are implying?

Capacitors are used in two different roles in AC motors.

A "start" capacitor gives the motor a momentary boost of torque
to overcome inertia (i.e., get things moving from a dead stop).
Something (e.g., a centrifugal switch -- a switch that *opens*
when the motor starts spinning) disconnects the capacitor from
the motor after it has served its purpose (i.e., once the motor
is *spinning*, the capacitor is not needed).

A *run* capacitor introduces a "delay" (phase shift) in the
second winding causing the rotor to move from one "phase"
to the next (and next and next, etc. thus giving motion).

Start caps tend to be of much larger "capacitance" (hundreds
of microfarads) while run caps are smaller (tens of microfarads).
Start caps tend to not be as fussy about actual values -- meet
the minimum requirement and you're OK. Run capacitors, OTOH,
are part of a somewhat tuned circuit so need to be matched
to the actual model motor (you can't just grab one from any
old motor and expect it to work).

[Some caps actually serve dual purposes!]

Assuming you've got a ~5,000BTU window unit, I suspect the
cap is (was?) a run capacitor. The fan just isn't that
big of a mechanical load! (unless a single motor is doing
double duty running the compressor *and* the fan!)

Chances are, if the ACbrrr was on/running during the "recent
storm", it is likely that the capacitor was damaged by a voltage
spike.

Most capacitors are relatively inexpensive (i.e., when compared
to the cost of a service call *or* replacement device). You're
probably looking at $10 or less -- with an hour or two of your time.
This is mainly because of the logistics of getting *to* the cap
in the first place!
- removing the ACbrrr from the window
- finding someplace to set it that your daughter won't complain :
- boarding up/closing the window to keep the critters at bay
- dismantle it, keeping track of screws and plastic pieces
- trace the wires to locate the capacitor
- get the markings off the capacitor (so you know what to buy!)
- noting which wires go where
- purchasing replacement (may not be a stock item; bring original
with you if possible in case there are mounting options!!)
- dealing with upset daughter who has this mess in the middle
of her bedroom floor while you're off watching football :
- reversing the procedure to replace, reassemble and reinstall
in window frame

Here's an exploded view of that model ACbrrr:
http://www.1stsourceservall.com/Appliance-Model/AJCQ10DCDW2
Click on "CABINET & COMPONENTS" for an overview of the entire
unit; "CONTROL PARTS" for details of the "circuitry".

Note that there are *two* capacitors, here. The capacitor
you are looking for is marked "1100" in the diagram. It appears
to plug into (?) the control board.

The other capacitor -- marked 1045 -- is probably for the compressor;
a much "heavier duty" motor (because it spends its life squeezing
gas molecules instead of PUSHING air around! : )

Assuming (!!) it is the capacitor, *this* looks to be a replacement:
http://www.appliancepartspros.com/ge-fan-mtr-capacitor-wj20x10116-ap3795059.html
at ~$9. Search for "WJ20X10116" (the part number for the manufacturer's
replacement component) for other vendors. You may find one at a
local "Sears", appliance repair shop, etc. PAY ATTENTION TO PRICING!
Some folks will have no qualms about charging you $50 for this part!
(There is a technical term for these people. They are called
CROOKS!) They operate on the premis that you are clueless and $50
is still cheaper than a replacement ACbrrr! :-/

(the first URL appears to sell that same capacitor for $16! frown)

We lost the cap for the (whole house) condenser fan a year or two
ago (~10 years old). I think it was a $10 part and 15 minutes
of my time (because the unit is outside, *large*, easy to access,
etc.).

If you go poking around inside, make sure it is UNPLUGGED. You
can also let it sit a while to ensure any residual charge has bled
off. Note that you can leave it *in* the window, UNPLUGGED for
a day to accomplish this! No need to wait until you've torn it
out of the window and made a mess -- and THEN have to wait!

Depending on where you live, you will, of course, be mindful of
any critters you end up dragging into the house! There is also
likely to be condensate in the bottom of the unit -- don't spill
that crud on your daughter's carpet!! :

Thanks to both of you. I was at my daughter's the other day but now I'm back home. I forwarded your advice to her. She has a friend who is pretty electric-knowledgeable and hopefully he will be able to help. For the cost of a capacitor it's worth trying a fix; although if Stormin's comment is correct about storm damage, that might be a different story.

On 8/27/2015 1:55 AM, Don Y wrote:

A *run* capacitor introduces a "delay" (phase shift) in the
second winding causing the rotor to move from one "phase"
to the next (and next and next, etc. thus giving motion).


[Some caps actually serve dual purposes!]

Assuming you've got a ~5,000BTU window unit, I suspect the
cap is (was?) a run capacitor. The fan just isn't that
big of a mechanical load! (unless a single motor is doing
double duty running the compressor *and* the fan!)

Chances are, if the ACbrrr was on/running during the "recent
storm", it is likely that the capacitor was damaged by a voltage
spike.

Most capacitors are relatively inexpensive (i.e., when compared
to the cost of a service call *or* replacement device). You're
probably looking at $10 or less -- with an hour or two of your time.
This is mainly because of the logistics of getting *to* the cap
in the first place!
- removing the ACbrrr from the window


The window or wall units I've serviced, the run
capacitor is typically in the compartment with
the thermostat and selector knob. I've been able
to remove, test, and replace the cap while the
unit is still in the wall, or the window. The
access is from indoors, so often I can work while
sitting on the floor in front of the unit. It's
a good idea to label the wires as you remove
them, or note the colors of the wires. So you
get em back together correctly.

--
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

On 8/28/2015 5:00 PM, wrote:
Thanks to both of you. I was at my daughter's the other day but now I'm back home. I forwarded your advice to her. She has a friend who is pretty electric-knowledgeable and hopefully he will be able to help. For the cost of a capacitor it's worth trying a fix; although if Stormin's comment is correct about storm damage, that might be a different story.


The tech should unplug the unit. Take the plastic
face plate off, and then a couple screws that hold
together the compartment with the selector and
thermostat. The run cap should be in that little
compartment. Good idea to tag or label the wires,
and note the colors before removing any.

--
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..