The working principle of reverse protection device
The working principles of the existing escalator anti reverse protection devices are mainly two types.
(1) the protection of anti reversal is realized by mechanical mechanism and electrical switch. In this protection device, the connecting rod is fixed on the switch rack, one end is set between two micro switches, and the other end is set on the ratchet chain. When the escalator goes up, the ratchet is revolving counter clockwise, and the connecting rod is centered on the fixed axis and the other end is pressed on the micro switch. By detecting the working state of the microswitch, the system can detect whether the escalator is in a state of non maneuverable reversal, so as to take corresponding protective measures, disconnect the power supply of the escalator and make emergency braking, or vice versa.
(2) use the speed monitoring element and the principle of velocity measurement to prevent the reverse protection. Generally speaking, if the operation speed of the escalator is at an under speed (less than 80% rated speed) and overspeed (greater than 120% of rated speed), the system will control the braking system through the output components, so that the escalator will stop.