DEVICE TO PROTECT LIFT ELECTRIC MOTORS FROM OVERLOADS AND ABNORMAL STATES

摘要

FIELD: lifts and elevators; protection devices. SUBSTANCE: invention relates to facilities aimed at protection of lift electric motors from thermal overloads and abnormal operating conditions. Said device has winch electric motor control unit with high speed switch unit and slow speed change-over unity and also time relay connected through power amplifier with actuator. Device incorporates also lift cabin door electric motor control unit, coincidence circuit and accurate stop unit. Time relay is adjustable in delay. In operation time of lift winch motor energized state at slow and high speeds is monitored and time of energized state of lift cabin door motor. If one of monitored time parameters exceeds preset value, lift control circuit is deenergized. Device features enlarged operating capabilities and provides protection of electric motor of lift winch high speed and electric motor of lift cabin door. EFFECT: provision of protection of lift motors at reduced supply voltage and mechanical overloads. 2 dwg