1. What is the Induction Motor Speed Formula?

The synchronous speed formula calculates the rotational speed of the magnetic field in an induction motor. It's a fundamental parameter for understanding motor performance and designing motor control systems.

2. How Does the Calculator Work?

The calculator uses the synchronous speed formula:

Where:

• \( N_s \) — Synchronous speed (RPM)
• \( f \) — Frequency of the power supply (Hz)
• \( p \) — Number of poles in the motor (must be even)

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

3. Importance of Synchronous Speed Calculation

Details: Knowing the synchronous speed is essential for motor selection, performance analysis, and troubleshooting. The actual rotor speed will be slightly less than synchronous speed due to slip.

4. Using the Calculator

Tips: Enter frequency in Hz and number of poles (must be an even number). Common frequencies are 50Hz or 60Hz. Typical pole numbers are 2, 4, 6, or 8.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between synchronous speed and actual speed?
A: Synchronous speed is the theoretical speed of the magnetic field. Actual rotor speed is slightly less due to slip (typically 2-5% less).

Q2: Why must the number of poles be even?
A: Induction motors require pairs of north and south poles, so the total number must always be even.

Q3: What are typical synchronous speeds for common motors?
A: For 60Hz systems: 3600 RPM (2-pole), 1800 RPM (4-pole), 1200 RPM (6-pole). For 50Hz systems: 3000 RPM, 1500 RPM, 1000 RPM respectively.

Q4: How does voltage affect motor speed?
A: Voltage affects torque but not synchronous speed. However, insufficient voltage may prevent the motor from reaching its designed speed.

Q5: Can this formula be used for DC motors?
A: No, DC motor speed is determined by different factors including applied voltage and field current.