There are 5 Different Method of testing capacitor with a multimeter.
Method 1: Traditional method to test and verify a capacitor (not recommended for all, but only for professionals)
Note: This method is dangerous, be careful to do this practice. Be sure to be a professional electrical engineer and there is no other option to check the capacitor because it can cause serious damage during this practice.) Now move on.
Suppose you want to verify the capacitor (for example, fan capacitors, ambient air condensers, etc.)
Warning and recommendations for testing a capacitor by method 1.
For better safety, use 24V DC instead of 230V AC. in the absence of the desired DC 24V system, you can use 220-224V AC, but you need to make a series of resistors (eg 1kΩ ~ 10kΩ, 5 ~ 50Watts) to connect between capacitor and 230V AC supply. So that i will reduce the current loading and unloading.
- Disconnect the suspected capacitor from the power supply or make sure that at least one capacitor cable is disconnected.
- Make sure it is fully downloaded.
- Connect the cables to the Capacitors terminal.
- Now connect these cables to a 230 V AC source for a very short time (about 1-4 seconds) [or for a short period of time when the voltage increases to 63.2% of the source voltage].
- Remove the safety leads from the 230 V AC power supply.
- Now, terminate the capacitor terminal (please be careful to do this).
- If it does a strong spark, then the capacitor is good.
- If it makes a slight spark, then it is a bad capacitor and change it immediately.
Method 2: Check and test a capacitor with an analog multimeter (AVO = ampere, voltage, ohm meter)
- Ensure that the suspected capacitor is completely discharged.
- Take an AVO meter.
- Select the analog meter in OHM (Always, select the highest range of ohms).
- Connect the meter wires to the capacitor terminals.
- Consider Reading and Compare with the following results.
- Short capacitors: the short capacitor will show a very low resistance.
- Open Capacitors: An open capacitor will not show any movement (deflection) on the OHM meter display.
- Good capacitors: Initially, it will show low resistance and then gradually increase towards infinity. It means that the condenser is in good condition.
Method 3: Test and check a capacitor via a digital multimeter
- Make sure the capacitor is discharged.
- Set the counter to the Ohm field (set it to 1000Ohm = 1k).
- Connect the measuring leads to the capacitor terminals.
- The digital device will display a few digits for one second. Keep reading.
- And then immediately return to OL (Open Line). Each test in Step 2 will show the same result as in step 4 and step 5. It is that the capacitor is in good condition.
- If there is no change, the capacitor is dead.
Method 4: Testing the capacitor by multimeter in capacitance mode
Note: You can do this test with a multimeter if you have a capacitance meter on your multimeter. Also, this method is good for small capacitors.
- Make sure the condenser is completely discharged.
- Remove the capacitors from the board or circuit.
- Now select “Capacitance” on your multimeter.
- Now connect the capacitor terminal to the multimeter’s cables.
- If the reading is close to the actual value of the capacitor (that is, the value printed on the capacitor container box).
- Then the capacitor is in good condition. (Note that the reading may be less than the actual capacitor value (the value printed on the capacitor container box).
- If you read a significantly lower or no capacitance, the capacitor is dead and you must change it.
Method 5: Check and test a capacitor through a simple voltmeter.
- Make sure you disconnect a single lead (do not worry if positive (long) or negative (short)) of the capacitor in the circuit (You can also disconnect completely when necessary)
- Check the rated capacitor voltage printed on it (as shown in the example below where voltage = 16V)
- Now charge this capacitor for a few seconds at the nominal value (not at the exact but lower value than, for example, charge a 16V capacitor with a 9V battery). Make sure that the positive (red) cable of the power supply is connected to the positive (long) conductor of the capacitor and negative to negative. If you can not find it or you are not sure, here is the tutorial on how to find the negative and positive terminal of a capacitor. Set the voltmeter to DC and connect the capacitor to the voltmeter by connecting the positive battery wire to the positive lead of the capacitor and negative to the negative.
- Note the initial voltage reading in the voltmeter. If near the capacitor voltage, the capacitor is in good condition. If it shows a very low reading, the capacitor is dead then. note that the voltmeter will show short-term reading as the capacitor will discharge the volt into the voltmeter and is normal.