troyphoto
Snarky Old Fart (in training)
From this site (I make no warranty about whether this will work, or send you to spark testing in the sky... use at your own riskThat is what I was thinking, but how do you measure the charge? Voltage across the capacitor?
That would make it easy.
I understand how to test a capacitor using a multimeter, but it typically requires removing the capacitor from the circuit. I was looking for a shortcut.
How to Run an AC Capacitor Test
In order to run your AC capacitor test, you will need to begin by turning off the power. It is very important that you start with this step for your own safety and that of the system.When the system has been turned off, you will disconnect all of the wiring. The amount of lines may vary depending on the AC capacitor itself. Be sure to completely disconnect everything.
After you have disconnected the wiring, it is time to drain any of the leftover voltage. Again, this is a very important step that must be completed before you carry out any testing. In some instances, you may need to remove rust from the terminal to expose the contacts.
Dual capacitors can be discharged with a 10,000 to 20,000 ohm resistor across all three terminals. Single capacitors can be discharged by placing the resister across the two taps.
Following the discharge process, you can jump into testing. To do this, you will want to use a multimeter with the MFD setting or uF setting.
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When testing, you will know that an AC capacitor is bad if it falls out of the appropriate range. A good capacitor will have a uF MFD reading around 5% of the storage capacity. This will vary by device, so be sure to check the capacity. Anything significantly outside of this standard reading should indicate that the system is bad.
In some cases, you can tell that a capacitor is bad without testing. Common indicators of this include a capacitor that looks expanded or bloated, signs of leaking dialectic fluid, an oil-soaked top cap, or any other physical issues.
