What is Braking Resistor for Motor Application?
You can find the use of dynamic braking systems in fans, centrifuges, conveyor belts and all those applications that need fast slow down and reversing. The market of braking resistors comprises automobile, mining, oil & gas, and others.
Understanding Braking Resistors
To understand “what is a braking resistor,” we need to go a little back to the basics. So, we know that resistor consumes huge energy and then goes on to disperse that energy in the form of heat, right? So when a mechanical system decelerates, it starts to act as a generator and creates a lot of electrical energy, which is then transferred back into the power circuit. In the power circuit, there is a resistor that consumes that large amount of energy and converts it into heat and also creates an instant braking effect. So, the entire process is called dynamic braking and the resistor used in it is called a braking resistor. A braking resistor plays a crucial role by creating a braking torque to rapidly slow down or stop the mechanical system. Overall, braking resistors are more reliable as they require very less service. They also have low ohmic values and high-power rating and that’s why they are mostly preferred over friction brakes when it comes to decelerating motors.
Motor Applications of Braking Resistors
When the power supply is removed, most DC motors will start to behave as generators because of their permanent magnets. And then the energy which is generated can quickly be dissipated by connecting a power resistor. Now given that there are no permanent magnets in AC induction motors, there is the induction of a magnetic field due to the rotating magnetic field.
Therefore, the use of braking resistors become imperative for applications when there is an urgent need for fast deceleration or where the motor speed exceeds variable frequency drive (VFD) set speed. The reason why braking resistors are used for motor applications is that they are the best at providing measured braking at an increased torque. It is essential to comprehend that a braking resistor needs to be correctly sized. For instance, it can stop the motor much faster and generate more heat if there is a lower ohmic value. Therefore, you should use a resistor that is bigger. All in all, the resistor safely dissipates the energy as heat.
Advantages of Braking Resistors
- They provide rapid braking of AC and DC motors.
- As compared to friction braking components, there is less wear and tear in braking resistors
- Braking resistors have longer equipment life and offer enhanced service reliability
- They also exclude the risk of thermal runaway
- They are specifically designed to efficiently absorb thermal expansions
The Bottom Line
The Bottom Line In general, braking resistors are crucial for the safety and reliability of motors. As compared to friction brakes, braking resistors are more in demand as they offer more resistor, average braking power, and less service. Please contact us if you have any queries related to the braking resistor for motor applications.