The process of aligning elevator guide rails, sills, and hoistway components exactly vertical during installation.
Full Definition
Plumb alignment is a fundamental installation activity ensuring that all vertical components—guide rails, sill brackets, hoistway walls, and the car frame travel path—are precisely vertical (plumb). It is achieved using a plumb line (piano wire tensioned from the top of the hoistway to the pit), laser levels, or digital inclinometers. Proper plumb alignment prevents guide shoe wear, car vibration, door misalignment, and sill gap variations over the travel height. In high-rise installations, the plumb line is temperature-corrected and wind-load effects are considered. EN 81-20 specifies maximum rail gauge tolerance (the perpendicular distance between opposite guide rails) and straightness tolerances.
