Testing Start Capacitor With Resistor

Remove the suspicious capacitor from its circuit.

Testing start capacitor with resistor.

Set the multimeter in continuity mode. Not all start caps use resistors as there are other ways to accomplish the task of reducing residual voltage in a capacitor. It s an all or nothing test that tells you if the capacitor is dead but it won t diagnose one that is still functioning weakly but about to stop working. Then use a screwdriver to open the appliance so you can locate the capacitor which is a metal tube that should be near the motor.

Wear work gloves and use a screwdriver with an insulated handle so you don t shock yourself. 6 ways to check a capacitor by using dmm amm avo. A start capacitor resistor also called a bleed down resistor is used to bleed off residual voltage in a start capacitor after it has removed from a motor circuit after start up. Complete the circuit by connecting a power supply of known voltage.

Start capacitors are not designed to dissipate the heat associated with continuous operation. A multimeter is an essential tool required to test a capacitor various methods of capacitor test using multimeter are discussed below. The continuity test method for a capacitor shows whether it is opened short or good. These capacitors will occasionally fail causing a compressor to fail to start.

Check test a capacitor using analog multimeter test check a capacitor with a digital multimeter checking capacitor by multimeter in the capacitance mode check and test a capacitor by simple voltmeter traditional method to test check a capacitor find the capacitor value by measuring the value of time constant. To check a start capacitor start by turning off and unplugging your appliance. Connect a known resistor typically a 10 kω resistor in series with the capacitor. Discharge it using a resistor.

Many single phase compressors require a start capacitor to assist in starting the motor. They are designed to stay in the circuit only momentarily while the motor. Understand what a run capacitor does the run capacitor provides continuous phase shifted current to the motor start winding allowing the motor to run with the design efficiency in the right direction with the appropriate torque with near unity power factor power factor near 1 0 if the run capacitor is failed often the motor. This one covers testing of the start capacitor.

What is important to note is that if the capacitor you are replacing had a bleed down. This video is part of the heating and cooling series of training videos made to accompany my websites. Symptoms include the hum of a garage door opener and its failure to start working or the failure of an air conditioner to cool the room. You can use an ohm meter to test a capacitor.