Frequency drive (VFD)
Running from the Keypad
What is a frequency drive (VFD)?
A frequency drive is an electronic device that sets the speed of an induction motor by changing the frequency of the voltage supplied to it. It is also known as a variable frequency drive (VFD), inverter or AC drive. It starts the motor softly, holds it at the required speed and stops it softly. In this application the drive is run from its keypad with factory settings.
Where is a frequency drive used?
It is used on pumps and fans to save energy, on conveyors and belts for speed control, and on cranes, lifts, mixers, compressors and machine tools. On pumps and fans even a small reduction in speed cuts energy use considerably.
Wiring and parameters
The supply goes to the drive's input terminals and the motor to its output terminals, with a suitable circuit breaker in front of the drive. Acceleration and deceleration times, the speed reference and the control mode are set with parameters. These basic parameters are the first thing to learn when starting with a drive.
What to watch out for
The motor nameplate values (voltage, current, frequency, speed) must be entered correctly in the drive. If a contactor is needed between the drive and the motor, it must not open while the drive is running.
Parts used
- Motor 3~
- M1
Run it in the simulator.
This circuit is ready in the CoilPath library. Open it, press the buttons and follow the current. It also comes with a wiring view and a panel layout.