Home air conditioning maintenance

Joined
Jan 22, 2011
Messages
7,852
Last edited by a moderator:
Joined
Jul 30, 2003
Messages
2,348
Location
GA
Ugh. A/C problems have caused me stress. If you get this repaired yourself with a $20 capacitor (maybe less), you win big. At least in my area you won't get one of the local crooks out to replace a capacitor ($20 and 30 minutes total in and out) for less than $400.

I've replaced a couple capacitors, a condenser motor and blower motor over the years. Grainger, Amazon and appliance parts houses usually have whatever you need. My 42 year old unit is still cooling and heating, knock on wood! I dread when something breaks that's not worth fixing because the next unit will cost more, be of less quality and be installed by some kid hyped up on Red Bull.

A couple months ago mine stopped cooling. Found the compressor not kicking on. One of the jumper wires on the... uhh.. thing the main power comes through with the brass contacts and makes a buzzing noise? ... had burned itself into. I replaced it and was back up running.
 
Joined
Dec 1, 2014
Messages
1,166
Location
California
These folks are pretty well respected in the Sacramento area...take a look at their YouTube video titled, "Why Do Capacitors Fail (Actually, Why Do Capacitors Suck!)"


Ed
 
Joined
Sep 6, 2007
Messages
2,179
Location
TX, USA
I didn't think the capacitor had anything to do with the fan motor. I thought they were for kick starting the compressor only. I could be wrong but that capacitor does look shot.

The way I understand it, there are 2 capacitance in that capacitor in the pic.
The high capacitance run the compressor and the low capacitance run the fan motor.
This is in the simplest system.

To OP, wash the coil also if it has not been suggested above.
Turn of the breaker switch to the outside unit before doing so.
Then, blow the condensate drain pipes in the inside unit.
You can make a vinegar solutions to rinse those condensate pipe.
If you don't have the ability to blow, call an AC person and they have the nitrogen tank to blow the pipe and do proper maintenance.
Replace the filter regularly otherwise the evaporator coil will plugged up with dust.
Use pleated filter instead of fiber glass (cheap) filter.
 
Joined
Jul 19, 2017
Messages
2,176
Location
Southwest CA, USA
Get a spare while you are at it. We were told the new ones are junk and fail often. Some brands are better but none are great. We have been through 3 over the past 10 years or so. Another family member is on pace for the same in the same area. We have pretty long hot summer days so that I’m sure doesn’t help.
 
Joined
Apr 19, 2008
Messages
25
Location
Ohio
Get a spare while you are at it. We were told the new ones are junk and fail often. Some brands are better but none are great. We have been through 3 over the past 10 years or so. Another family member is on pace for the same in the same area. We have pretty long hot summer days so that I’m sure doesn’t help.
 
Joined
Jun 26, 2018
Messages
325
Location
AR
In the future you can "test" before buying any parts. While it's humming, Use a small green twig to "pushstart" the fan. If it comes up to speed without much effort its very likely the start capacitor.

Doing this several times. or fan on top for multiple cycles killed my fan a few years ago. So I had to replace both, (rent house, wasn't permitted to fix it myself)
 

Snagglefoot

Thread starter
Joined
Dec 31, 2017
Messages
12,431
Location
SE British Columbia, Canada
Thanks everyone. I went to town and bought a new capacitor from EMCO, our local wholesaler. It was 45/5 instead of 45/7.5. Close enough I guess.

Installed it in 5 min. I had to shim it inside the steel mounting band as it was 1/8 “ smaller in diameter. Turned on the 220 V and the 110. Turned the A/C off at the control panel than back on. She started up and I have nice cold air. Here’s some pics. Enjoy and pour a cold drink. Made in China, so I’ll see if I can get a spare in Calgary. Price was $15 USD.

0EBD796F-FF05-4DA2-A040-379205D26EB6.jpeg
CEAF8E37-3E17-4D1C-952A-F84EB44AE575.jpeg
92C329DA-17EF-4088-9D00-E65465FC9E09.jpeg
24D195F8-0D34-49AF-A098-89821C88091A.jpeg
 
Joined
Sep 26, 2017
Messages
1,434
Location
Under the Hood
Thanks everyone. I went to town and bought a new capacitor from EMCO, our local wholesaler. It was 45/5 instead of 45/7.5. Close enough I guess.

I am NOT an Electrician and know very little about it.
I do know enough to electrocute myself.

OP - I would go online and buy the exact MF capacitor, not something close.
The 'original 7.5 (micro fareds) has a tolerance of +/- 6%
Your 5 MF is already too low.

Like others have said:
Buy something made in USA and get a spare.

Good luck / stay cool.
 
Joined
Sep 18, 2012
Messages
6,092
Location
DFW
I'm not a real expert on this, but I wouldn't run a 45/5 long term in place of a 45/7.5, You are undersizing the capacitance by 30% for the fan motor and the eventual result could be premature failure of the capacitor or motor. It's fine for a while, but I would get the correct value. If I'm off base here please let me know.
 
Joined
Sep 26, 2017
Messages
1,434
Location
Under the Hood

Original capacitor (right side in photo)
Looks like the 'top' of contact area is bulged (convex).
I would still get the correct 7.5 MF capacitor.

Get yourself a multimeter that reads MF.
I recently fixed a neighbor's air compressor that had a bad capacitor.
He was going to put it out to the curb, but I fixed it for $20.
He was happy and he thought I knew what I was doing.
 
Joined
Oct 9, 2004
Messages
13,085
Location
Cincinnati, OH, USA
A 45/10 would be better than a 45/5-the fan motor amperage will increase & shorten the life of the fan motor, or even cause it to overheat & shut down on its thermal overload. A little higher capacitance is better than lower. You can always keep the 45/5 as an emergency spare one.
 
Joined
Oct 4, 2009
Messages
520
Location
Litchfield, Ohio
While the 45/5 may work you really need to get the 45/7.5 for it to be right. Running a motor with a run capacitor of a lower value will cause the motor to work harder than it needs to.

Also note that these are not start capacitors they are run capacitors. Dual run to be specific in this case. Start capacitors have a black plastic case and are only in the circuit for a few seconds to kick start the motor or compressor. Some units do use both start and run capacitors.
 
Joined
Jan 22, 2011
Messages
7,852
Good luck finding an American made one. Even the name brands are chinese made. My outdoor unit was installed in 2000. I have changed my capacitor and contactor every ten years. I am on my third set of chinese made parts. I haven't had a failure yet. Change them every ten years and it will be fine.
 
Joined
Jan 1, 2003
Messages
2,448
Location
Daytona Beach
Thanks everyone. I went to town and bought a new capacitor from EMCO, our local wholesaler. It was 45/5 instead of 45/7.5. Close enough I guess.

Installed it in 5 min. I had to shim it inside the steel mounting band as it was 1/8 “ smaller in diameter. Turned on the 220 V and the 110. Turned the A/C off at the control panel than back on. She started up and I have nice cold air. Here’s some pics. Enjoy and pour a cold drink. Made in China, so I’ll see if I can get a spare in Calgary. Price was $15 USD.

View attachment 110228 View attachment 110229 View attachment 110230 View attachment 110231
No such thing as close enough in this case.
 
Joined
Oct 4, 2009
Messages
520
Location
Litchfield, Ohio
Good luck finding an American made one. Even the name brands are chinese made. My outdoor unit was installed in 2000. I have changed my capacitor and contactor every ten years. I am on my third set of chinese made parts. I haven't had a failure yet. Change them every ten years and it will be fine.
Amrad makes them here all day long. Now they do cost more but you get what you pay for.
 
Top