How do you check a capacitor to see if it's good ?

Question

It's a 5mfd used on a furnace motor. I have a volt-ohm meter. Please give me step by step instructions. Thanks

Answer 1

Before doing anything with the capacitor ensure it is discharged. While operating it could have either 120VAC or 240VAC applied, and may hold enough charge to give you a nasty jolt.

With an analog meter, measure resistance of the capacitor. You should see the needle start off showing a low resistance which will slowly increase. Reverse the leads and the same readings should occur. This is a quick check which will give no indication as to capacitance value or leakage, but will indicate whether the capacitor is shorted or dried out.

You will need a capacitance meter to determine the value. Higher end meters will also measure leakage as well as have a function to condition or restore the capacitor to proper operation.

Answer 2

see you later as a capacitor isn't electrolytic then you definately can actual verify it on a digital meter, Meter set to extreme ohms ( over 1meg ohm ) and purely connect the two meter leads in the time of capacitor , there would desire to be no examining different than for a flick of the reveal because of the fact the capacitor expenditures ( in line with fee ). Electrolytic capacitors are slightly trickier yet a stable approach for the beginner is to earnings the suspect cap with a nicely-known stable one utilising the meter and evaluating the readings. on the different hand some digital meters have a capacitance verify facility equipped in. those multi meters are quit low-cost presently ( $50. 00 ) . Cheers Pete observe to those that don`t examine the question appropriate !! A digital Multi mter grew to become into precise Lifetime R X one million does not teach leakage purely lifeless short !!

Answer 3

Multiply the Charge (not the capacitance) held by the capaciter and the voltage running through it and the number should be around 5mfd