VAPROMATIC LRS (LIQUID RESISTANCE STARTER)

The Liquid Resistance Starter (LRS) operates on the difference in electrical resistivity between the liquid electrolyte and the vapour formed inside the electrode chamber. At the time of motor starting, the initial rotor current partially vaporizes the electrolyte, which automatically adjusts the rotor resistance and provides the optimum starting torque.

As the motor accelerates, thermal changes within the electrolyte gradually reduce the resistance. A timed short-circuit contactor then bypasses the remaining low resistance once the motor reaches the required acceleration stage.

This continuous reduction in resistance ensures smooth, progressive, and stress-free motor acceleration, allowing the motor to achieve full operating speed in the shortest possible time. Since the resistance automatically decreases in proportion to the motor speed, it minimizes operator intervention and helps prevent motor overheating and burn-out.

The Liquid Resistance Starter (LRS) is designed as a multi-stage starting system, where each stage provides the equivalent resistance of several fixed resistance stages. The starter consists of electrode assemblies immersed in an electrolyte solution and housed inside a heavy-duty sheet steel tank.

The number of electrode assemblies is selected according to the motor kW rating, the required number of starts per hour, and the motor acceleration (run-up) time to ensure reliable and smooth starting performance.

A Control Box is provided for the electrical operation of the Liquid Resistance Starter. It houses all essential electrical components, including relays, contactors, push buttons, selector switches, indicating lamps, and other control and protection devices, ensuring safe, reliable, and efficient operation of the starter.