The brake resistor’s function is to dissipate heat so it can slow down a mechanical system. The process it achieves is called ‘dynamic braking’. To decelerate an electric motor, kinetic energy is transformed back into electrical energy. This energy is dissipated by using a power resistor.
Dynamic braking can be rheostatic and regenerative.
Rheostatic: means that energy is dissipated as heat in a resistor.
Regenerative: means the electric power is fed back in the system.
Regenerative braking typically comes at a higher cost.
Brake Resistors in Practice
Brake resistors can be used for both smaller motion systems, and also for larger constructions such as trains or trams. The alternative is called ‘friction braking’. There are many advantages of dynamic braking resistors over friction braking. For example:
- Lower wear and tear of components,
- Control motor voltage within safe levels,
- Faster braking of AC and DC motors,
- Less service required and higher reliability,
- Faster deceleration.
Brake Resistor Technology
In most cases, the wire-wound resistor is the most popular. They tend to have a ceramic core and are fully welded. They’re usually encased in a frame to create a safe distance from other parts. To increase dissipation capability, the frames are often executed with cooling fins, fans or even water cooling.
Braking Resistor DC Motor
Because of their permanent magnets, most DC motors will behave as generators as soon as they are removed from the power supply. The generated energy can be dissipated by connecting a power resistor as load. This is different from AC induction motors which don’t have permanent magnets
Braking resistors are used for applications where the motor speed exceeds the speed that is set by the variable frequency drive (VFD) or when fast deceleration is required. They can provide controlled braking at an increased torque.
Brake Resistor Supplier South Africa
EP Normand supplies quality equipment related to the drive industry. Correct design and matching of products for applications as intricate as electronic gearing, cut-to length lines, flying saws and accurate strip guiding are standard services. We are proud to have our own panel shop onsite and that we are able to handle projects of any size.
All drives that EP Normand distributes carry a 12 month warranty. EP Normand has a comprehensive, fast turnaround service as we keep spare parts ex-stock. A team of technicians are available to assist you on an any day, all hour basis. Technicians are fully trained on all the products available from EP Normand. For more information, contact our team!