The set of mechanical, electrical, and electromechanical protection devices required by EN 115-1 to stop an escalator or moving walk automatically in the event of a hazardous condition, preventing passenger injury.
Full Definition
EN 115-1 mandates a comprehensive array of safety devices on escalators and moving walks. Key devices include: (1) Step or pallet missing/broken — a sensor detects a missing step position in the step band and stops the escalator; (2) Step chain slack or breakage — chain tension sensors stop the machine if a chain breaks or slackens; (3) Comb plate impact — mechanical deflection or pressure sensor under the comb plate stops the unit if a step rises abnormally; (4) Drive chain safety device — prevents operation if the drive chain between machine and step chain sprocket breaks; (5) Handrail entry guard switch — stops the escalator if the newel guard is displaced by entrapment; (6) Skirt panel obstruction switch — stops the unit if an object becomes lodged between the step and skirt; (7) Overspeed governor — stops and applies brakes if step speed exceeds 20% of nominal; (8) Underspeed/reverse direction detection — monitors step speed and direction; (9) Step level device / anti-reversal — prevents reverse travel; (10) Emergency stop buttons — at top and bottom landings and at intermediate landings in long escalators. All safety device trips must be manually reset to prevent restart.
