Abstract
Various types of elevators, according to the drive system, the exchange two-speed elevators, escalators VVVF exchanges, exchange regulator speed elevators, because of its low cost. Huoti current capacity and simple ladder used in the more advanced of the current governor of the elevator on the widely used as a PLC logic control, supported by a dedicated elevator surge governor or a governor frequency control system. Because in the past use of the relay control, because the use of the intermediate relays and relay more time, the area needs more room, use high failure rate, they have been replaced by the PLC control. The three stations designed to exchange the three-tier two-speed elevator control of the PLC as an example, the analysis of PLC in the elevator apply.
