1. What is Synchronous Speed?

Synchronous speed (N_s) is the speed of the magnetic field rotation in an induction motor. It represents the theoretical maximum speed the motor can achieve and depends on the power supply frequency and number of poles in the motor.

2. How Does the Calculator Work?

The calculator uses the synchronous speed formula:

Where:

• \( N_s \) — Synchronous speed in RPM (revolutions per minute)
• \( f \) — Power supply frequency in Hz
• \( p \) — Number of poles in the motor (always an even number)

Explanation: The formula shows that synchronous speed is directly proportional to frequency and inversely proportional to the number of poles.

3. Importance of Synchronous Speed

Details: Synchronous speed is crucial for understanding motor performance characteristics, including slip calculation (the difference between synchronous and actual speed), torque production, and efficiency.

4. Using the Calculator

Tips: Enter frequency in Hz (typically 50 or 60 Hz) and number of poles (common values are 2, 4, 6, or 8). The number of poles must be an even number.

5. Frequently Asked Questions (FAQ)

Q1: Why is the number of poles always even?
A: Induction motors require pairs of north and south poles to create the rotating magnetic field, so pole count is always even.

Q2: What is the relationship between poles and speed?
A: More poles result in slower synchronous speed. A 2-pole motor at 60 Hz has 3600 RPM, while a 4-pole motor at 60 Hz has 1800 RPM.

Q3: Why doesn't the motor reach synchronous speed?
A: Induction motors operate at slightly less than synchronous speed (called slip) to induce current in the rotor and produce torque.

Q4: What are typical synchronous speeds?
A: For 60 Hz systems: 3600 RPM (2-pole), 1800 RPM (4-pole), 1200 RPM (6-pole). For 50 Hz systems: 3000 RPM, 1500 RPM, 1000 RPM respectively.

Q5: Can this formula be used for synchronous motors?
A: Yes, but synchronous motors actually rotate at synchronous speed (unlike induction motors which have slip).