Speed Electrical Motors
Reference data and engineering information about speed electrical motors for electrical applications.
Overview
Engineering reference data for Speed Electrical Motors in electrical engineering.
Key Formulas
Ohm's Law
Voltage = Current × Resistance.
Power
Electrical power.
Energy
Energy = Power × Time.
Variables
| Symbol | Description | Unit |
|---|---|---|
| Voltage | V | |
| Current | A | |
| Resistance | Ω | |
| Power | W |
Motor Speed Data Table
The following table provides typical speeds for small and medium electrical motors operating at standard power frequencies.
Number of Poles | Speed at Rated Load(rpm) | Speed at Rated Load(rpm) | Synchronous Speed (No Load)(rpm) | Synchronous Speed (No Load)(rpm) |
|---|---|---|---|---|
| 2 | 3450 | 2850 | 3600 | 3000 |
| 4 | 1725 | 1425 | 1800 | 1500 |
| 6 | 1140 | 950 | 1200 | 1000 |
| 8 | 850 | 700 | 900 | 750 |
Source: engineeringtoolbox.com
Speed Estimation for Other Pole Counts
While the table above lists the most common configurations, you can estimate speeds for other pole counts using the fundamental synchronous speed formula . The actual speed under load is slightly lower due to slip. A rough estimate for rated load speed can be obtained by applying a typical slip factor (often 2-5% for small/medium motors) to the calculated synchronous speed.