How do I calculate the energy savings when using a Constant Torque rated VFD in a Constant Torque Application?


28 September 2021

Information needed to determine the energy savings for a variable frequency drive (VFD) system in a constant torque application.

Product Line:
All constant torque rated Altivar Drives.

All constant torque rated drives, All serial numbers.

What is the percentage of energy usage reduction compared to the reduction in speed?

In a constant torque application, The energy used is directly proportional to the speed of the motor.   At 25% speed, 25% energy is used.  At 50% speed, 50% energy is used.  This is different than in variable torque applications where the reduction in power usage is greater than the reduction in speed.

When calculating energy consumption for constant torque applications, The percentage of motor speed is used to determine energy usage.