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pregnant capacitor

3 posts in this topic

 Well it's a nice cozy summer day about 80 degrees outside,or 90 or more,and your AC blower is on inside, you have it set to 68, but it is blowing hot air in the house. what do you do?

     Do you call your HVAC guy? and pay a $95 dollar service fee or do you play detective and try to see what's wrong? OK so you dont throw in the towel yet, you ease outside the house to the condenser unit,thats the thing that runs  outside in the yard while your house is being cooled,yeah that thing, you find it dead,yeah that's right shes dead in the water, a big old ac unit nothing happening or maybe the fan is working, but not the compressor, you say to yourself, wow I know this is a problem but what could be wrong? It could be the breaker,you flip it, nothing ,(it flips back off, or it dont, or the fan runs, but the compressor don't), This my friends could be a capacitor gone bad. Oh yeah it could be a shorted compressor (not likely unless the unit is 20 years old),or it could be a wire corroded off the compressor and shorted out to the unit(not likely, but posible) but it might be the capacitor. The capacitor goes to the herm sealed compressor(HERM), the fan(FAN)and the common©which feeds both, How do you tell if it"s bad? The capacitor is a round canister about 2 inchs or 3 around and 4 maybe 5 inchs high ,it has maybe 5 wires attached to it, It has 3 legs marked C, HERM, and FAN. This is the run cap for the unit, this is what helps start the unit up after the "contactor" has called for cooling. Depending on the size of it,it could be $25 or $35 dollars. If you aint sure thats whats wrong,but suspect that it might be,then check it. First look at it, if it looks swelled up, puffy or pregnant:Especially if the top of it is all rounded out swollen, well thats a start! The top of it should be flat,with no liquid oosing out of it ,not rusted out or leaky, Ok what next? Make a note of which wires go to fan (brown) what goes to herm (fat red) what goes to C (white)2 fat white and 1 skinny white etc. Remove the suspect capacitor. Then do a continuity test on this sucker, if it reads straight continuity on any point between fan,C,or Herm ,its shorted , which means its inner lining has busted. On an old analog meter the needle should hop slightly between each point if it is good, and when you reverse the leads same thing. OK, If it reads open at any point between C, HERM ,or FAN, its bad,or if it reads straight continuity between fan, or C, or herm,It's bad.     Second test: take a cheater cord (a discarded lamp  cord with spade clips will do)  and place the clips on herm and common , after making sure the cap aint got a dead short in it, as noted above, shove the cheater cord into an outlet with 125 volts ac for about 2 seconds, then take and short the prongs on the cheater cord across a something metal, you should get a POP! this is a good thing! the cap is holding a charge . no POP no good ,Just dont hold it to your tongue! LOL! Oh yeah, If it explodes in yer face that means you aint checked it for continuity to see if its shorted internally,HEH HEH! Anyhow if it dont pop you have a bad capacitor.You can do the same test between fan and common. This is not hard to fix but it IS dangerous! you must make sure no power is on while attempting to remove the capacitor! Snatch out the quick disconnect thing near the unit or shut off the breaker. This aint rocket science! Drink no brew till the AC will cool!   

next=  "contactors"... we aint alone lol!

    

 

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Need appliance parts? Call 877-803-7957 now!

This is all good information except the cheater cord, someone is going to get shocked trying that bit of info. A Ohm meter is all you need to test a cap.Sears sells a meter with cap testing capability for 29.00 also can be used for temp mesurement with appropriate sensor lead.

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You are right about the getting shocked part. when dealing with electricity,it can be very dangerous, dont attempt to mess with electricity, you can be killed, thats for sure . I always tell my novice custs to bring a cap by my store and let me check it for them. But this may not be possible in this forum . Good post mopar!

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