The European standard for elevator installations in seismic zones, classifying lifts by seismic risk category and requiring specific design and operational measures to withstand earthquakes.
Full Definition
EN 81-77:2019 classifies lift installations into seismic categories 0–4 based on the peak ground acceleration (PGA) of the site and assigns requirements proportional to the hazard level. Higher categories require reinforced guide rails and brackets to resist lateral loads, a seismic unintended movement detection switch (SUDS) that stops the elevator upon detecting ground vibration above the trigger threshold, car and counterweight derailment protection, and a defined procedure for inspecting and resetting the lift before returning it to service after a seismic event. After a seismic event triggers a shutdown, a competent person must inspect guide rails, ropes, counterweight, car, and buffer before restarting. The standard is mandatory in EU seismic zones (Italy, Greece, Turkey, Romania) and increasingly referenced in the Middle East and Asia.
