Variable Frequency Drives
Certification Program

Find AHRI Certified® Variable Frequency Drives.


Program Scope

This standard applies, within the heating, ventilating, air-conditioning and refrigeration (HVACR) context, to 60 Hz VFDs used in the control of asynchronous induction motors. The range includes all those found within a building including: low voltage (≤ 600 V) and drives that are stand alone, not mechanically integrated into motors.

Variable Frequency Drive
A power electronic device that regulates the speed of an alternating current (AC) motor by adjusting the frequency and the voltage of the electrical power supplied to the motor.

Program Scope Inclusions
This certification program includes only base VFDs which may be incorporated into other configurations, (i.e. bypasses, filters, enclosures) with the following specifications:

  • Designed for use in the control of asynchronous induction motors in HVACR products only designated by the manufacturer;
  • Found within a building that are low voltage (= 600 Volts) and drives that are stand alone; and
  • Custom units – designated to have significantly different system efficiencies harmonic performance or motor stress.

Program Scope Exclusions
This certification program does not include:

  • VFDs mechanically integrated into motors;
  • Brushless DC motor controllers; and
  • Motor Insulation Stress for 208 V VFDs.

Certified Ratings
  • Drive System Efficiency, %
  • Motor Insulation Stress, peak V and rise time, µsec; and
  • Power Line Harmonics, total harmonic current distortion, %