A sliding elevator door configuration in which two door panels part symmetrically from the centre of the opening, each sliding to opposite sides to maximise clear opening width relative to the available door pocket space.
Full Definition
Centre-opening (CO) doors divide the total door width equally between left and right panels; each panel travels half the clear opening width, requiring only half the door pocket depth per side compared to a single-panel side-opening configuration. This makes CO doors the preferred choice where wall depth adjacent to the entrance is limited. Standard CO configurations are 2-panel (one panel per side) or 4-panel (two panels per side for wider openings), with the inner panels telescopically linked to the outer panels. The door operator is mounted centrally and drives both panels via a reversing linkage. EN 81-20 limits maximum kinetic energy during closing (10 J for CO doors) and maximum closing force (150 N). CO doors provide faster passenger throughput for wide entrances (900–1300 mm clear width) and are the dominant type in commercial high-rise elevator installations worldwide. Safety light curtain coverage must span the full clear opening width from floor to ≥1800 mm AFF.
