Should Have Listened To That Little Voice!

[junquecol]

This past week after watching some videos on how AC units most commonly fail, found out in high heat, the capacitor is the most common fail item. Thought about picking up a "spare, or two" as we have two units, both of which use the same capacitor. Yesterday, one of the units reminded me I should have picked up a spare. Luckily in my junk pile I had a replacement capacitor. Should have listened to that little voice. Today went to supply house, and picked up three caps, along with extra fuses for disconnect

 

[Gotcha6]

This past week after watching some videos on how AC units most commonly fail, found out in high heat, the capacitor is the most common fail item. Thought about picking up a "spare, or two" as we have two units, both of which use the same capacitor. Yesterday, one of the units reminded me I should have picked up a spare. Luckily in my junk pile I had a replacement capacitor. Should have listened to that little voice. Today went to supply house, and picked up three caps, along with extra fuses for disconnect

Had the same problem with my pool pump 2 weeks ago. Ordered one online & had to wait 1 week before it arrived, but the pool is okay. Surprised at the difference in price & shipping on these things, even with the same brand & model#. Even though the old one was bad, it still sparked when I shorted to discharge it before it was removed...

 

[Rob in NC]

I've learned to be a quasi HVAC tech with my current 20+ year old AC unit. Multiple times replacing the start capacitor, run capacitor, once on the blower motor and a couple condensate pumps. At this point, I dont know if it's best to get in front of it and replace the whole thing or use it till it dies or at least needs a major repair. Of course when it does die, it'll do it during the hottest day of the week when prices are out of control!

 

[Ricksmi]

I have replaced the capacitor a couple times on my 15 year old unit after the tech showed me how so now I keep a new one on the shop just in case another one blows. Also learned keeping the coils clean helps as well.

 

[mpeele]

There's another reason to have a couple of extras. I got and additional 6 years out of a compressor by adding a second start capacitor.

 

[Danny Batchelor]

Anyone have an easy way to test capacitor without a special tool?

 

[Gofor]

Not a definitive test, but if the top (where the connectors are) is domed up any, it is probably bad or soon to fail.

Monday night at the firehouse, we had a discussion on this very subject, as one of the guys had just had to replace the capacitor in his. The scuttlebutt from him and a couple other individuals that are contractors, was their HVAC people suggest that repairing an older unit may be better than buying new, as the durability of the new ones, regardless of brand, seems not to be as good.
'
caveat: May want to take the validity of that statement as "my MIL's brother's son's second cousin's neighbor said...."

 

[pop-pop]

Here is how I measure capacitance of electric motor capacitors.

Basically, apply 110Vac and measure the voltage across and current through the cap. The fuse/breaker is in case the cap is shorted. The 5 and 10 loop coils are for amplifying the current reading if needed for your amp meter.

The formula is “2652 x amps / volts equals microfarads”.

I predict my friends @Michael Mathews and @JNCarr will have to derive the equation just as I did years ago. It is fairly easy and will bring back memories of 377 on a slide rule.

 

[Dee2]

Here is how I measure capacitance of electric motor capacitors.
View attachment 230542
Basically, apply 110Vac and measure the voltage across and current through the cap. The fuse/breaker is in case the cap is shorted. The 5 and 10 loop coils are for amplifying the current reading if needed for your amp meter.

The formula is “2652 x amps / volts equals microfarads”.

I predict my friends @Michael Mathews and @JNCarr will have to derive the equation just as I did years ago. It is fairly easy and will bring back memories of 377 on a slide rule.

Now there is a brief How-to for the Resources forum.

 

[mpeele]

Usually the can will be distorted or leaking.

 

[Gotcha6]

Here is how I measure capacitance of electric motor capacitors.
View attachment 230542
Basically, apply 110Vac and measure the voltage across and current through the cap. The fuse/breaker is in case the cap is shorted. The 5 and 10 loop coils are for amplifying the current reading if needed for your amp meter.

The formula is “2652 x amps / volts equals microfarads”.

I predict my friends @Michael Mathews and @JNCarr will have to derive the equation just as I did years ago. It is fairly easy and will bring back memories of 377 on a slide rule.

Ah, yes! A slide rule! Someone here that still has one will have to knock the dust off of it. I've been buying them on Goodwill auctions to collect.