1. What is Synchronous Speed?

Synchronous speed is the theoretical speed at which the magnetic field rotates in an AC electric motor. It represents the speed at which the motor would run if there were no slip between the rotor and the rotating magnetic field.

2. How Does the Calculator Work?

The calculator uses the synchronous speed formula:

Where:

• \( RPM \) — Revolutions per minute
• \( f \) — Frequency in Hertz (Hz)
• \( Poles \) — Number of magnetic poles in the motor

Explanation: The formula calculates the synchronous speed based on the electrical frequency and the number of poles in the motor construction.

3. Importance of RPM Calculation

Details: Knowing the synchronous speed is essential for motor selection, speed control applications, and understanding motor performance characteristics in various industrial and commercial applications.

4. Using the Calculator

Tips: Enter frequency in Hz and number of poles (must be even number, typically 2, 4, 6, or 8). All values must be valid (frequency > 0, poles ≥ 2 and even).

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between synchronous speed and actual speed?
A: Synchronous speed is theoretical, while actual speed is slightly lower due to slip in induction motors. The difference is called slip speed.

Q2: Why must the number of poles be even?
A: Magnetic poles in AC motors always come in pairs (north and south), so the total number must be even for proper magnetic field formation.

Q3: What are typical frequency values?
A: 50 Hz in most countries, 60 Hz in North America and some other regions. Variable frequency drives can provide other frequencies.

Q4: How does pole number affect motor speed?
A: More poles result in lower synchronous speed. A 2-pole motor runs faster than a 4-pole motor at the same frequency.

Q5: Can this calculator be used for all motor types?
A: Primarily for AC synchronous and induction motors. DC motors and other special motor types use different speed calculation methods.