SimPhase Induction Motor Calculations (IMC) Program calculates the steady-state running conditions for one three-phase induction motor at a time. The IMC program uses induction motor standard per-phase equivalent circuit for the calculations.

The IMC program has 4 options :

- Option 1 calculates the motor starting conditions at zero speed.
- Option 2 calculates the maximum torque and the speed at which it occurs.
- Option 3 calculates motor steady-state running conditions :

- The motor has no variable frequency drive (VFD) speed control : Conditions are calculated for your combination of terminal voltage and frequency. The motor speed (or the slip) must be known before the calculations.

- Option 4 calculates motor steady-state running conditions :
- If the motor has no VFD speed control : Conditions are calculated for your combination of terminal voltage and frequency. The speed and the slip are unknown before the calculations. Image 1 below shows some results.
- If the motor has a VFD speed control : Conditions are calculated for your value of motor speed. Image 2 below shows some results.

In option 1, if the selected motor has a VFD speed control, the program includes in the calculations the necessary voltage boost by the speed control.

Option 3 corresponds to conventional induction motor calculations using the standard equivalent circuit (voltage, frequency and speed (or slip) are known before the calculations).

Option 4 uses the information about the mechanical load provided when you define the motor.

Following blog post has examples using option 4.

Following image shows the values calculated by option 4 when the motor has no speed control. Notice that the speed and the slip are among the calculated values.

Following image shows the values calculated by option 4 when the motor has a VFD speed control. Conditions are calculated for a motor speed equal to 1000 rpm.