How do I know if my capacitor is bad

[REDGI]

13 month old GE model AEC14AY
All of a sudden on 7/26/2021 stopped cooling. Always maintained with clean parts and it just quit blowing cold air. Out of warranty now… Thank goodness we have portable Ac but i would like to fix myself. Way too expensive for a tech

 

[TheELF]

What do you expect people to tell you with that little information?
Do you have the ability to measure the capacitor you are talking about? Why do you even suspect a capacitor?

 

[herm0016]

is the compressor running? did you check to see if the A coil is froze up? is the fan still kicking on? etc.

 

[maluckey1]

13 month old GE model AEC14AY
All of a sudden on 7/26/2021 stopped cooling. Always maintained with clean parts and it just quit blowing cold air. Out of warranty now… Thank goodness we have portable Ac but i would like to fix myself. Way too expensive for a tech

Do you mean the fan startup capacitor? IF so, they're pretty cheap, and easy to install by yourself. You can test it with a multimeter to see if it's failed. Plenty of YouTube videos

 

[[DHT]Osiris]

They usually burst, or bulge. Not a requirement for a failed cap, but a really good way to confirm.

 

[Leeea]

Hire an HVAC tech.


The motor cap is not the first thing to diagnose. Not even the second. You gave us no where near enough information.

Your post indicates a level of ignorance that means your ill suited to be poking at 240v equipment. Hiring a HVAC tech will save you money.

They usually burst, or bulge. Not a requirement for a failed cap, but a really good way to confirm.

He is referring to the cap for the AC starter winding on the 240v AC compressor motor. Those caps typically do not budge or crack before they go. They tend to be in a rather heavy duty metal casing. I have replaced several in my time.

It is a rather trivial thing to test for function and requires no special tools.


Also, 13 months? Sounds like the batteries in his thermostat died.

 

[sdifox]

Hire an HVAC tech.


The motor cap is not the first thing to diagnose. Not even the second. You gave us no where near enough information.

Your post indicates a level of ignorance that means your ill suited to be poking at 240v equipment. Hiring a HVAC tech will save you money.



He is referring to the cap for the AC starter winding on the 240v AC compressor motor. Those caps typically do not budge or crack before they go. They tend to be in a rather heavy duty metal casing. I have replaced several in my time.

It is a rather trivial thing to test for function and requires no special tools.


Also, 13 months? Sounds like the batteries in his thermostat died.

It's a 115VAC window unit...

 

[Leeea]

It's a 115VAC window unit...

-chuckles-

I will take my exit now.

 

[Greenman]

Look at the cap, if the top is bulging it's toast.

 

[pcgeek11]

13 month old GE model AEC14AY
All of a sudden on 7/26/2021 stopped cooling. Always maintained with clean parts and it just quit blowing cold air. Out of warranty now… Thank goodness we have portable Ac but i would like to fix myself. Way too expensive for a tech

Is it blowing air, but the air is not cold?
Is it not blowing air at all?
Is the compressor turning on?

If it is blowing warm air, the compressor isn't turning on it could just be a loss of refrigerant. It may or may not be serviceable.

If it isn't blowing air at all it could be the blower or starting cap for the blower.

If the compressor is not turning on it could be low pressure or a starting cap for the compressor.

Get a meter with a capacitive Check function and you can test them.

 

[REDGI]

Ok thank you all for your help and advice… I spoke to a tech on 6ya and explained the issue I’m having with Ac, and that’s what he told me might be the problem. Sorry for the lack of information so you all could give me a better response… as I see I have some frustrated responses. So here’s the full information

GE MODEL AEC14AY 115 window ac unit.
Blowing warm air
Nothing frozen up
All part cleaned and have always been cleaned.
But now when I turn on, it starts to surge the lights in room, so I’ve unplugged and running a backup portable AC. Not the same power, but it will do until we get the problem fixed. I’m pretty mechanically inclined and definitely search YouTube for information on how to fix most things. Once I remove from window, I will have a better idea and can look at it with cover off. Thanks again for all who helped!!! Much appreciated

 

[herm0016]

Ok thank you all for your help and advice… I spoke to a tech on 6ya and explained the issue I’m having with Ac, and that’s what he told me might be the problem. Sorry for the lack of information so you all could give me a better response… as I see I have some frustrated responses. So here’s the full information

GE MODEL AEC14AY 115 window ac unit.
Blowing warm air
Nothing frozen up
All part cleaned and have always been cleaned.
But now when I turn on, it starts to surge the lights in room, so I’ve unplugged and running a backup portable AC. Not the same power, but it will do until we get the problem fixed. I’m pretty mechanically inclined and definitely search YouTube for information on how to fix most things. Once I remove from window, I will have a better idea and can look at it with cover off. Thanks again for all who helped!!! Much appreciated

we all apricate you actually getting back to the thread. we get a lot of threads started with a vague question and the OP never to return or comes back and says we are all wrong or argues with our assessments. it could be a cap on a compressor, but i really thought that the window units would have universal type motors and not induction motors. could be wrong though. take some pics when you open it up.

 

[REDGI]

Will do for sure
Thanks again

 

[Leeea]

Ok thank you all for your help and advice… I spoke to a tech on 6ya and explained the issue I’m having with Ac, and that’s what he told me might be the problem. Sorry for the lack of information so you all could give me a better response… as I see I have some frustrated responses. So here’s the full information

GE MODEL AEC14AY 115 window ac unit.
Blowing warm air
Nothing frozen up
All part cleaned and have always been cleaned.
But now when I turn on, it starts to surge the lights in room, so I’ve unplugged and running a backup portable AC. Not the same power, but it will do until we get the problem fixed. I’m pretty mechanically inclined and definitely search YouTube for information on how to fix most things. Once I remove from window, I will have a better idea and can look at it with cover off. Thanks again for all who helped!!! Much appreciated

You liked my post! That must mean you want me to comment more!

The behavior of your air conditioner is consistent with accidently switching the heat mode on.

On through wall units like yours that is typically set with the mode switch on the remote.



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But now when I turn on, it starts to surge the lights in room, so I’ve unplugged and running a backup portable AC.

You mean dim the lights for a moment? (in an LED light, this can appear as a flicker or a bright flash)

That is more of an indication of crappy wiring then of any issue with the AC. However, we can glean a lot of information from it. Specifically, that much current draw indicates mechanically the fan is spinning up and the compressor is engaging. Your capacitor is fine if the fan is spinning, it is just used to put the one winding out of phase so the motor can start. Capacitors do not increase current draw as they fail in this application. Nor will the capacitor increase voltage on the line.

If it was just the fan engaging it would likely not pull enough juice to effect the lights even on a poorly wired circuit. So likely your compressor and fan are engaging. We can rule out control board / electronic failure also.

The bad news is odds are you are either:
out of refrigerant
your compressor has failed (internal seals etc) and is no longer pressurizing the coolant

 

[Leeea]

it could be a cap on a compressor, but i really thought that the window units would have universal type motors and not induction motors. could be wrong though. take some pics when you open it up.

Units manufactured for the USA will typically have the capacitor. These types of out of phase windings are more Energy Star efficient, and are mandated in most states.

The motors without capacitors in this application are split phase induction units, where one winding is is slightly off from the others to allow the motor to start. This is not typically used in the US these days because these types of motors are less inefficient, and ACs are heavily regulated on efficiency here.


Universal motors are never used for this application in any country. Universal motors have brushes that wear out and greatly increased EMI. These are typically seen in power tools where the increased torque at low RPMs, easily variable speed, and ability to reverse are acceptable trade offs for the reduced lifespan. Universal motors are also interesting in that they will run off of DC current.

 

[pcgeek11]

Based on the fact that the lights dim when the compressor turns on it has a failed compressor.

 

[REDGI]

Thank you, you’re probably right

 

[REDGI]

You liked my post! That must mean you want me to comment more!

The behavior of your air conditioner is consistent with accidently switching the heat mode on.

On through wall units like yours that is typically set with the mode switch on the remote.



-------------------------------------------------------------------------------------


You mean dim the lights for a moment? (in an LED light, this can appear as a flicker or a bright flash)

That is more of an indication of crappy wiring then of any issue with the AC. However, we can glean a lot of information from it. Specifically, that much current draw indicates mechanically the fan is spinning up and the compressor is engaging. Your capacitor is fine if the fan is spinning, it is just used to put the one winding out of phase so the motor can start. Capacitors do not increase current draw as they fail in this application. Nor will the capacitor increase voltage on the line.

If it was just the fan engaging it would likely not pull enough juice to effect the lights even on a poorly wired circuit. So likely your compressor and fan are engaging. We can rule out control board / electronic failure also.

The bad news is odds are you are either:
out of refrigerant
your compressor has failed (internal seals etc) and is no longer pressurizing the coolant

I’ll be taking it down this weekend and hope to figure out what’s wrong… a lot of YouTube videos I’m sure. And I will take all of the advise and suggestions on this forum. Thanks

 

[sdifox]

Op, did you buy it with a credit card? Does your CC offer extended warranty? Look into that before you open it up, you may get it replaced by the CC company.

 

[MtnMan]

The motor start capacitor on my A/C starts both the compressor and fan.
First realized that the interior fan was running, but the outdoor unit wasn't (I can hear it when in the bathroom). Checked, buzzing sound, and fan motor hot. Killed the power, and started checking. Removed cover and noted capacitor was bulging a bit.
Found an equivalent replacement and all was good.

 

[REDGI]

We’ll I’ve taken cover off… started it up and outside fan started and spinning but compressor not turning on. I’m not sure about capacitor because it looks ok but it could still be bad. But something crawled up in there and died. I think just a lizard 🦎 because I inspected it and rinsed thoroughly. Doing it by myself so I was able to use rolling cart to take it out. We run a daycare and can’t have that toxic smell. I’m not sure if I want to remove capacitor myself. Although YouTube videos show it’s not that hard to do. Just make sure I discharge it… we shall see

 

[REDGI]

Op, did you buy it with a credit card? Does your CC offer extended warranty? Look into that before you open it up, you may get it replaced by the CC company.

We’ll parts and warranty for a year and I just found out GE gives a 5 year warranty on the compressor. But not sure how to tell if it’s compressor or not and they charge $99 just to come out… 🤔

 

[PowerEngineer]

FWIW, a bad starting capacitor would also be my first guess.

Induction motors look like short circuits until they start coming up to speed. They need a slightly shifted (i.e. second) electrical phase to provide starting torque. If they don't get it, they will just sit there heating up and humming. The starting capacitor's function is to provide that slightly shifted second phase on start-up and it drops out after the motor gets spinning.

If the capacitor on the motor driving your compressor is bad then there is no shift for that second phase and the motor will not start (and the heavy current draw will dim the lights).

Good luck!

 

[REDGI]

Before taking it out I obviously need to discharge it. but I would like to have a replacement on hand to finish the maintenance on it. With 60+15/250 as shown in the picture, are those numbers enough to order the right one? Or do I need to remove and access the rest of the the numbers?

 

[sdifox]

Yeah, it's a three prong dual run capacitor, it has 65uf and 15uf and it is 250vac. Should be easy to get and replace. Just make sure you note which wire goes to which terminal.