How to Test an HVAC Capacitor with a Multimeter

Capacitor Safety Warning

Capacitors store electrical energy and can shock you even when power is off. Always discharge capacitors before testing.

Types of HVAC Capacitors

• Run capacitor: Keeps motor running efficiently
• Start capacitor: Provides extra torque for startup
• Dual capacitor: Combines compressor and fan capacitors

Testing Procedure

1. Turn off power to the unit
2. Discharge the capacitor safely
3. Set multimeter to capacitance mode
4. Connect leads to capacitor terminals
5. Compare reading to rated value on capacitor

Interpreting Results

• Within 5% of rating: Capacitor is good
• More than 5% low: Capacitor is weak
• No reading: Capacitor is dead