How to Discharge an Air Conditioner Capacitor


Air conditioner compressor and fan motors use large capacitors to help the motors start under load. These high voltage, high-capacitance devices can hold a lethal charge for days or months after the unit is disconnected. Before testing, changing or disconnecting an air conditioner capacitor, you must ensure it is first discharged. A tool called a grounding rod will safely discharge a capacitor in an air conditioner or other high voltage appliance.

Things You'll Need

  • Safety glasses
  • Grounding rod
  • Screwdriver with insulated handle
  • Turn off power to the air conditioner unit at its disconnect switch. Put on safety glasses. Connect the wire lead on the grounding rod to the air conditioner's green chassis ground lug screw. Loosen the lug and place the lead connector beneath the ground lug and tighten the terminal firmly.

  • Touch the probe to one terminal of the capacitor and hold it there for 20 seconds. Repeat this step for each terminal on the air conditioner's capacitor. Some air conditioner units place two capacitors inside one housing. These capacitors have three terminals.

  • Hold the screwdriver by the insulated handle. Touch the tip of the screwdriver to a capacitor terminal, then allow the screwdriver shaft to touch another terminal. A charged capacitor will cause a spark, but the capacitor will also discharge. Do this for all three terminals. This ensures the capacitor is fully discharged to earth ground.

Related Searches

Promoted By Zergnet



You May Also Like

  • How to Check a HVAC Capacitor

    A capacitor is an electrical device used to store power for appliances that need an extra surge of energy to begin working....

  • How to Replace the Capacitor on an AC Unit

    When a capacitor goes bad it will cause the AC unit to work harder and use more electricity. A bad capacitor can...

  • How to Test an Air Compressor Motor Capacitor

    Air compressor capacitors store electrical energy for later discharge. Capacitors contain two plates that build up and store electricity until the electricity...

  • How to Test a Trane Capacitor

    Heating and air conditioning capacitors store electrical energy to allow high voltage discharge or to smooth the incoming electricity. Capacitors collect and...

  • What Is an AC Capacitor?

    An air conditioner (AC) capacitor can be likened to the battery of a car, because they both store electrical energy. In the...

  • How to Discharge a Capacitor

    Discharging a capacitor means taking safety precautions and dissipating the energy from a capacitor into heat with a 12-volt automotive bulb. Safely...

Related Searches

Check It Out

22 DIY Ways to Update Your Home on a Small Budget

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!