Fedders Window AC Unit Dead--Diagnostic Advice?
 

Hey Folks,
I have an older Fedders (consumer grade) one-room size window AC unit, 120V.
It's well over a decade+ old...was given to me by my brother-in-law as he was
no longer using it. I've owned it for about 5 years, but only used it for one
summer (I live in apt. in NYC, had weak electrical, the building got an
elect. upgrade and then I used it). It has been stored in a closet for almost
2 yrs and was working perfectly before stored...never had a problem. We've
got a heat wave so I pulled it out and plugged it in. I've got a problem....
When I first switched it on, if memory serves, the fan worked and the
compressor kicked in but only very briefly...perhaps 10-30 seconds (if I
remember correctly)....then it popped the circuit. Usually, I plug the AC
directly into it's own extension cord, a very heavy gage item, but since I
had the AC removed for the 2 yrs, I had put a surge suppresor unit on the
extension cord and had a fan and 2 lamps connected to it. I saw the
thermal/overload protector on the surge surpressor had popped. After the
latter reset, I tried again to turn on the AC, this time only the fan went
on..I could hear a sound of a load straining but this time the compressor
didn't go on. I think that is the sequence of events.
OK. I removed the AC unit from the surge suppressor, and plugged the AC
directly into the extension cord. Now, not only wasn't the compressor kicking
in, but, when I turned the cooling to 'off' and only turned the fan on, the
fan wouldn't work. I could hear the motor load with current, but no turn
over. All the fan speeds resulted in the same failure.

Basically, now the AC unit will not operate at all, either in fan or cooling
mode, and it just gives a 'hum' when switched on.

Unfortunately, there's no model# on the unit...or if there was the sticker is
not longer there.

I got my multimeter out & removed the control panel. On a cursory inspection,
the power cord appears OK, the fan switch contacts appear to be be working.
I see the big capacitor in there, is that the cap for the start up circuit?
Any contactors that need to be checked? I never really worked on an AC uit
before.
I've got pretty good mechanical skills and passable electric/electronic
skills (if I get some guidance).
I could use some advice on how to troubleshoot this (and if needed, how to
find the model# ).
I couldn't find anything on the web regarding general AC repair and the HVAC
newsgroup seemed moe industry base, so I came here.
Anyone care to give it a stab?
Thanks a bunch!
Cheers,
Neal

First off, what size A/C are we talking about? If it's like 5,000 or
6000 BTU, I would not waste time, they are so cheap today and more
energy efficient. You could pick one for $100.
But a good way to start troubleshooting is check to see if you have
voltage at the unit. Is it 110V or 220V?

On Sun, 07 Aug 2005 00:13:27 GMT, Lovegas wrote:

Hey Folks,
I have an older Fedders (consumer grade) one-room size window AC unit, 120V.
It's well over a decade+ old...was given to me by my brother-in-law as he was
no longer using it. I've owned it for about 5 years, but only used it for one
summer (I live in apt. in NYC, had weak electrical, the building got an
elect. upgrade and then I used it). It has been stored in a closet for almost
2 yrs and was working perfectly before stored...never had a problem. We've
got a heat wave so I pulled it out and plugged it in. I've got a problem....
When I first switched it on, if memory serves, the fan worked and the
compressor kicked in but only very briefly...perhaps 10-30 seconds (if I
remember correctly)....t

Basically, now the AC unit will not operate at all, either in fan or cooling
mode, and it just gives a 'hum' when switched on.

My "Guess" is that the motor is your prob..Might be needing
cleaning, or has leaked out oil and now is basically seized...Or just
needs a bit of oil or a good cleaning.

"Mikepier" wrote in message
But a good way to start troubleshooting is check to see if you have
voltage at the unit. Is it 110V or 220V?

Didn't read the whole post did you?

"Lovegas" wrote in message

Basically, now the AC unit will not operate at all, either in fan or
cooling
mode, and it just gives a 'hum' when switched on.

Unfortunately, there's no model# on the unit...or if there was the sticker
is
not longer there.

Usually on a sticker or lable behind the grill.



I could use some advice on how to troubleshoot this (and if needed, how to
find the model# ).
I couldn't find anything on the web regarding general AC repair and the
HVAC
newsgroup seemed moe industry base, so I came here.
Anyone care to give it a stab?

In dog years it is 84 years old. In window AC years, it is about that old
also.

The fan motor may be trying to start, but gummed up bearings can be a
problem. Most small motors have sealed bearings and no way to oil them.
You can put a couple of drops of oil on the shaft, but it is a long shot
that enough will get to the bearings to last any time. Try spinning the
fan (blower wheel) by hand and then turn on the switch while it is still
turning. Get your fingers out first! Sometimes you can get it moving like
that, but it is just a quick fix, not a real cure. I got by for three days
like that until I was able to get a new motor.

The compressor can be the same way, or it may have lost its charge. Before
you invest much time and money in it, check out the prices of new units.
Small bedroom sized units can be bought new for less that the minimum an AC
tech has to charge to troubleshoot and repair it.

These things have joined the ranks of throwawy items.

I do not think it is ever a good idea to put a window A/C unit on an
extension cord unless it's one of those heavy duty appliance cords, and
even then only do it until you can run a separate, dedicated 20A
circuit for it.

Edwin Pawlowski wrote:
Before
you invest much time and money in it, check out the prices of new units.
Small bedroom sized units can be bought new for less that the minimum an AC
tech has to charge to troubleshoot and repair it.

I guess you didn't read my entire post.

First off, what size A/C are we talking about? If it's like 5,000 or
6000 BTU, I would not waste time, they are so cheap today and more
energy efficient. You could pick one for $100.

"Mikepier" wrote in message
ups.com...

Edwin Pawlowski wrote:
Before
you invest much time and money in it, check out the prices of new units.
Small bedroom sized units can be bought new for less that the minimum an
AC
tech has to charge to troubleshoot and repair it.

I guess you didn't read my entire post.

First off, what size A/C are we talking about? If it's like 5,000 or
6000 BTU, I would not waste time, they are so cheap today and more
energy efficient. You could pick one for $100.


But I replied to the OP first. HIS post stated the voltage. YOU made
essentially the same comment I made. What is the problem? apples - oranges

On Sun, 07 Aug 2005 14:27:24 GMT, "Edwin Pawlowski"
wrote:


"Mikepier" wrote in message
oups.com...

Edwin Pawlowski wrote:
Before
you invest much time and money in it, check out the prices of new units.
Small bedroom sized units can be bought new for less that the minimum an
AC
tech has to charge to troubleshoot and repair it.

I guess you didn't read my entire post.

First off, what size A/C are we talking about? If it's like 5,000 or
6000 BTU, I would not waste time, they are so cheap today and more
energy efficient. You could pick one for $100.


But I replied to the OP first. HIS post stated the voltage. YOU made
essentially the same comment I made. What is the problem? apples - oranges



Starting current for an air conditioner can be as much as 5 times more
than the running current. The voltage drop from any sort of common
extension cord, or outlet strip when faced with this current may drop
the voltage low enough to where it will not start the compressor.

Portable AC's should never be connected to power strips or ordinary
extension cords. Also, keep your lamps off of this extension cord.
The only proper extension cords are the rather thick and stiff cords
that are sold as "Air Conditioner Extension Cords". These should be
as short as possible. The shortest ones are just 3 ft.

The larger portable AC's ( 12000 BTU's) run best on their own
circuit.

Your house wiring can also be poor quality for the starting and
running of air condition for the same reason. If there are any high
resistance points (ex. cheap back-stabber outets) or long runs of
circuits that are already heavily loaded, you may not be able to start
the compressor.

In the worst case, you will burn out your compresser motor without
tripping any breakers as the rotor will lock and the coils will just
cook.

Beachcomber

Beachcomber is correct in his advice, except for the statement that the
worst case scenario would be burning the compressor up due to low
voltage caused by bad wiring. That is the second worst-- the worst would
be starting a fire. Actually though, in this case, that would be less
likely since you would not leave the unit plugged in if it does not run.
(at least I would hope not) I agree about backstabbed outlets.
Backstabbing, and the manufacture of outlets and switches capable of
being backstabbed should be outlawed. Larry

Since neither motor will run, it sounds like a bad dual run capacitor
to me, but that is just a guess. Anything more than that and I would
buy a new window shaker.

Stretch

Edwin Pawlowski wrote:
But I replied to the OP first. HIS post stated the voltage. YOU made
essentially the same comment I made. What is the problem? apples - oranges
Hey, its all good. Just busting your chops.