Aluminum alloy lifts are a type of cranes and are mainly used for high-altitude operations. The safety problem of aluminum alloy lifting platform cannot be ignored.
Electrical protection of aluminum alloy lifting platform:
Lifting platform open-phase and wrong-phase protection.The circuit is composed of three intermediate relays to form the open-phase and wrong-phase protection.
Broken rope protection. The circuit interrupted rope interlock switch is connected in series to the control circuit. When the switch is activated, the circuit of the lifting platform has no electricity, the motor cannot start and stops running.
Speed limiter interlock switch. When the speed limiter is actuated, the switch will act to cut off the power of the motor, and the motor cannot start or stop running.
Limit switch and limit switch. The aluminum alloy lift table circuit is equipped with an upper limit switch and a lower limit switch. When the limit switch is actuated, the power supply in the ascending or descending direction is disconnected respectively, and the elevator stops running.
The fence interlock switch can only start up when the base fence is closed and the normally open contact of the protection switch is closed.
Some construction lifts are also equipped with floor door interlock switches. The lift can only be started after the landing doors are all closed.
Overload protection of the motor Hoisting motor interlock contacts are connected in series with the zero relay. Cut off the hoisting motor power supply when the coil circuit operates.
Zero position protection The circuit is composed of a zero position relay and the zero position contact of the controller which cannot be reset automatically.
Overspeed protection In order to prevent the eddy current brake from suddenly losing the exciting current after the main control device of the motor is released, causing the motor to run out of control and causing the phenomenon of overspeed, a current relay should be set in the exciting circuit. Its interlock contact should disconnect the common brake solenoid coil circuit or the stop circuit of the running contactor.
