What does the synchronous speed of a motor refer to?

The synchronous speed of a motor refers to the speed at which the magnetic field of the motor's stator rotates. This speed is determined by the frequency of the supply voltage and the number of poles in the motor, following the formula:

Synchronous Speed (RPM) = (120 × Frequency in Hz) / Number of Poles.

This speed represents the theoretical maximum speed of the motor under ideal conditions, where it operates in synchronization with the frequency of the voltage supply. When referring to the maximum speed at which it will run, it highlights the limit the motor can achieve relative to its design and input power.

Understanding synchronous speed is crucial for applications where precise motor control is necessary, such as in HVAC systems, as it helps in determining the performance characteristics of the motor and ensuring it functions within its designed parameters.