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## How do you change the frequency of a motor?

VFDs can be used to control AC motor speeds by changing the motor’s frequency without sacrificing the output power of the motor. This is done by **turning the speed pot** (explained in section three) of an AC motor drive.

## What is frequency control method?

Variable Frequency Control is a **method that is used to control the speed of an induction motor**. The synchronous speed and therefore, the speed of the motor can be controlled by varying the supply frequency.

## What happens if 50Hz motor is driven at 60Hz?

When a 50Hz single phase motor is brought to 60Hz the start function can be upset because the **motor reaches the centrifugal switch speed 20% earlier than normal**. When it does, the starting torque of the motor is suddenly reduced. It could fail to speed up further and never reach normal running speed.

## How does frequency affect current in a motor?

4 Answers. An AC motor stator is an inductance. In an inductance, the lower the **frequency**, the lower its impedance. So having constant voltage over it, the current will rise if the frequency gets lower.

## How does frequency affect horsepower?

You can use the HP and torque equations to verify this relationship. When a VFD increases frequency above 60 hertz, HP and torque do a complete flip flop. HP remains at 100 percent, and **torque decreases as frequency increases**. The torque reduction occurs because motor impedance increases with increasing frequency.

## What happens when frequency changes?

From these equations you may realize that as the frequency increases, **the wavelength gets shorter**. As the frequency decreases, the wavelength gets longer.

## Can you control the speed of an AC motor?

The most common way of controlling AC motor speed is **changing the motor’s frequency**. … The AC frequency can be adjusted using a six-step inverter, vector flux or pulse-width-modulation. A six-step inverter or variable voltage inverter rectifies the AC power to DC power, and then switches to imitate a sine wave.