How To Control Frequency With 0 To 10 Volts DC In Allen Bradley VFD

In this article, we are going to learn, how to control frequency with 0 to 10 volts dc in allen bradley vfd. Zero to ten volts is a very standardize control signals use in many different applications. This can be used in many drives to control the speed of the motor or control the frequency in variable drives.

Generally, we use potentiometer as a source of speed in variable frequency drives. And here we will learn controlling by zero to ten volts using a potentiometer. First of all, let see the wiring of a potentiometer. Below is a wiring diagram and internally structure of a potentiometer circuit.

This is a wiper inside potentiometer. If you will open a potentiometer from back, you will find the wiper over there. And if you rotate that nope of potentiometer, the wiper will be moving from inside. This wiper divides the resistance, between the three terminals. When you connect voltage to the terminals of potentiometer, we will receive some other output because of that resistance. When we rotate the wiper, the resistance will change and output voltage will also be changed.

Wiring of Potentiometer and VFD

Let's see the wiring, that is the wiring diagram below, of a potentiometer and a variable frequency drive. We have here, a potentiometer and a drive (variable frequency drive). So extreme ends is connected to the ten volts and zero volts. This 10 volts and 0 volts is coming from inside the drive. When you will supply the input, this 10 volts dc and 0 volt will come automatically from inside the drive. So you have to connect two terminals over there.

So this middle point which will gives you zero to ten volts, based on the wiper position, is connected to a number 13 terminal. It is written on the drive and manual as well.  So by this way, you can control drive's frequency from the external source. Please watch this video tutorial from below to understand it better.