Axis Controls stock a range of Dynamic Braking Resistors, suitable for installation in a brand new electrical control system, or as a retrofit adjustment. Dynamic braking resistors are a compact and cost-effective way to control the braking and dissipation of heat, or energy produced when an electric motor driven machinery is stopped.
What does a Braking Resistor do?
Generally, a resistor is used to consume; or dissipate heat. By doing this, they can be used to stop, or slow down, a mechanical system. To decelerate an electric motor in this way, kinetic energy is transformed back into electrical energy.
Generally, the speed of modern three-phase motors is controlled by variable frequency drives; also called variable speed drives and inverters. The AC frequency of the VFD output voltage determines the motors' speed and can be adjusted accordingly. If this drive is serving as a generator, this generated energy results in a voltage increase in the DC bus of the variable speed drive. To prevent damage to this DC bus; the voltage must remain below a certain value but feeding this energy back into the grid is not economical. Instead, this extra energy is converted into heat using a dynamic braking resistor.