Industrial automation is unimaginable without power resistors. AC Drive panels, Variable Frequency Drives (VFD), Microprocessor Frequency Controllers and Inverters are all devices which employ resistors for motor starting, braking and speed control functions.

Important applications of various drives and industrial automation include:

• Lifts, cranes and escalators
• Conveyor belts
• Robotics
• Earth moving equipment
• Printing machines
• Grinding machines
• Cement plants and concrete mixers
• Step ring motors

The two main resistor types used in industrial automation and drives are:

• Stator series resistors -
  

  Three phase induction motors generate huge input current during startup time that can potentially damage their stator coils. Stator series resistors are variable resistors used to prevent this damage.

• Dynamic braking resistors -
  

  The most popular type of resistors used in the Automated Drive industry. DBRs are used during the braking process of AC induction motors. To stop an AC induction motor, its rotating speed has to be reduced drastically. DBRs perform this function by converting the excess electrical energy (from the motor) to be dissipated as heat. DBRs come with both internal external heat sinks depending on the amount of peak heat that is expected to be generated. DBRs are produced using multiple manufacturing techniques depending on the specific application for which it is used. These include aluminium clad, metal clad braking resistors, and wire-wound resistors.

Why KWK?

KWK has been the preferred partner of several leading manufacturers of Elevators, Cranes, Locomotives and Material Handling systems for supplying Dynamic braking resistors.

KWK has the expertise to design and manufacture customised application specific resistors that are particularly good at handling high pulsed powers. Dynamic braking resistors from KWK come with varied resistance, power and current ratings. KWK Resistors also require very little service and maintenance.

These heavy-duty resistors are designed to be rugged so as to withstand heavy loads and frequent start-stop cycles.  Resistors come in different form factors like edge-wound and wire-wound resistors.

The KABR, KAHB and KCBR series of Dynamic braking resistors from KWK are popular options.