Resistance boxes are used to add resistance to an electric motor circuit for modifying the performance characteristic of slip ring induction motors of EOT cranes, rubber mills, steel rolling mills, cement mills, power plants, conveyors, coke oven, blowers, etc. For speed control and developing starting torque with low starting currents. They are also used as Dynamic Braking Resistor for VVVF AC drives, electric loading of ac alternators, degeneration, and dynamometers. Resistors are designed to meet the requirements of both A.C. & D.C. applications.