HVAC Run Capacitors
September 25, 2010 by Air Phase - All About Air Conditioning
Filed under hvac
I show how to test run capacitors. **Special Shout out** to: Big Wave Dave in Salt Lake City, Utah.
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@jwablueeyes I know that it seems odd but you can run your run caps in parallel to add up the rating you need. I don’t recommend making this a common practice. It’s good in a pinch.
hi im jeff,im a teck ,i seen a odd thing.it was six 5mfd in the place of 30 mfd,is there a problem with me leaveing them that way,i never herad of something like this in school,i finish school last year jeff.ahner@yahoo.com, thank you
@automan1223 Yes.
what if you had the same 5/60 uf 370 vac but your available replacement was 5/60 uf 440 vac ? would the extra voltage rating be ok ?
@MrTERRYD55
hi,terry.
you could try the capacitor 55/7.5uf or 55/5uf capacitor.
good video.it is very useful for us to learn more about the hvac capacitor.
@MrTERRYD55 The problem is that the compressor side on the old run cap is 50. You could use a 50/5 X 440. A 45 wouldn’t give you enough capacitance, causing the compressor to not start at times and making it overheating while it would be running.
what is the problem using the step up on the voltage …for instance the old cap unit is a 50 / 5 x 370 and used 45/5 x 440 what is the harm if any….the fan side on the old unit was bad…
@MattixIcexBaby I made this video with my older Fieldpiece HS33. Now I have the HS36.
Wat model of meter is this? I have seen a few techs using it before but never looked at it closely, I need a new meter, this must be a good choice.
MFD is the old terminology for uFD so dont confuse it with mFD!
@estrelladelnorte1308 no you cant
no you cant
Capacitors usually fail open or short, rarely change value (split-phase caps are plus/minus twenty percent anyway, so a 5MFD could be anywhere from 4 to 6). You can test with a normal DVM by charging the cap with a 9V battery. Just short the battery lugs to the cap terminals for a few seconds, take it off, wait a minute or so, then test with the meter set to DC voltage. It should start out very close to 9V and slowly drop as the cap drains through the meter. Zero volts means a bad cap.
@estrelladelnorte1308 You really need a multi meter with a mfd setting to do it right. There is a way to using the volts setting while the system is running. I don’t find it to be very reliable.
Can you test it with a multimeter that doent have a mfd test choice ? is ther another way to do it and how??
ur the man!
@disconnected007 It could be a run cap. Some run caps have a terminal that is connected to an overload relay.
i got this submersible pump a single phase IM 220V. Now it wont run unless u give it a initial turn. i found out the capacitor (8MFD 500V with 3 terminal) bulge up. My question is… is it a run or a start capacitor? and why is there 3 terminal? got a hard time looking for it in the market… can i replace with something the same?
@Guacatechs Yes.
Can you replace a bad capacitor with with a replacement of the same MFD but higher voltage?
@bsnegi24 Look at the motor. The run cap info should be on the data sticker.
@GregA64 Those are two separate problems. It is possible that your compressor windings are ohming to ground.
I have a campbell hausfeld compressor where the Run Capacitor ruptured and leaked out it’s fluid. Is this just normal failure or is something else going on? I have had problems recently that the Compressor wouldn’t run beyond 40 PSI without tripping the breaker. Was this all just the normal progression of the Run Capacitor going bad?
I have a campbell hausfeld compressor where the Run Capacitor ruptured and leaked out it’s fluid. Is this just normal failure or is something else going on? I have had problems recently that the Compressor wouldn’t run beyond 40 PSI without tripping the breaker. Was this all just the normal progression of the Run Capacitor going bad?