端站保护装置（End station protection device）.doc

端站保护装置（End station protection device） The terminal protection device is located at the top and bottom of the well, which mainly prevents the malfunction and damage of the electrical control device, resulting in the bumping of the elevator and the occurrence of the accident at the bottom. The device should be sufficiently direct and reliable. Terminal protection has three kinds: forced speed device, limiting device, limit switch. 1. forced speed change device In the elevator control system with long stroke limit speed switch and short stroke limit speed switch two, are respectively connected with high-speed and medium speed given relay coil, as shown in Figure 3 and figure 3 - 21JGS 18JQF circuit and JZS circuit. In the low speed elevator control system, as shown in Figure 3 - 17 in the CKF and CK express contactor coil in series with the selector switch. The speed adjusting switch are respectively installed on the two end station, its installation position slightly behind normal speed, only when the operation of the elevator to the two terminal station can not be normal speed, touch iron device installed in the car, in contact with the touch wheel speed switch, the switch off the circuit high speed relay release, lift by high speed change into a low, flat layer parking. As the device moves regularly during the normal operation of the elevator, the maintenance personnel are required to periodically check the reliability of the device. In order to prevent the rapid landing and bumping of the elevator, people and equipment accidents occur. 2. terminal station spacing device The spacing device is designed to prevent the passage of the elevator. In case of hit the top and bottom up lift, when the retarder action, lift speed to the parking position, lift still can not stop running, the car hit iron and the limit switch touch wheel contact, limit switch contact control system for elevator direction relay or contactor circuit, make its release the elevator stopped running.