A VFD controls AC motor speed and torque by adjusting output frequency and voltage. Selecting from motor kilowatts alone can cause nuisance trips, inadequate starting torque, overheating, or poor process performance.
Collect motor data
- Rated voltage, full-load current, power, and frequency
- Rated speed, efficiency, power factor, and insulation
- Connection method and inverter-duty rating
- Encoder or feedback requirements
- Motor cable length and output-filter needs
Define the load
Fans and centrifugal pumps differ from conveyors, mixers, hoists, and extruders. Record minimum and maximum speed, acceleration, deceleration, starts per hour, breakaway torque, reversing, and peak overload.
Check supply and environment
Match input voltage and phase. Review short-circuit level, grounding, harmonics, temperature, altitude, dust, moisture, enclosure rating, cooling, and cabinet spacing. Derating may be required.
Plan braking, safety, and control
Fast deceleration may require a braking resistor, brake unit, or regenerative solution. Confirm safe torque off, motor protection, emergency-stop architecture, analog or digital control, network protocol, option cards, and commissioning software.
Request a drive
Send US² Automation the existing drive code, motor nameplate, application, supply, communication protocol, environment, quantity, and delivery location.