Research Article

Enhancing Interpretability of Data-Driven Fault Detection and Diagnosis Methodology with Maintainability Rules in Smart Building Management

Table 19

Elevators & Escalators – Common Faults.

ProblemDesignConstructionMaintenance

Inaccurate elevator car levelling with the landing

Elevator car is not levelled with the landing floor

Poor levelling can cause trip hazard
The design guidelines for permanently installed electric lifts should be adopted in accordance with SS 550, CIBSE guide D, BS 5655-6, BS 5655-11, BS EN 81-20 or equivalent.
The stopping accuracy of the elevator car against the landing floor should be ±10 mm.
Global standards on lift safety in accordance with ISO/TR 11071-2 (i.e., assumption of safe operation assured to 125% of rated load, assuring reliability of electric safety devices, mechanical devices built and maintained in accordance with good practice) should be collated.
The guidelines for construction and installation of permanently installed electric lifts should be implemented in accordance with SS 550, BS 5655-6, BS 5655-11, BS EN 81-20 or equivalent. The safety rules for construction to be guided in accordance with BS EN 81-50 or equivalent.
Every lift should be provided with a capacity plate located in a conspicuous place inside the car, indicating the rated load in kilograms and, in the case of passenger lifts, the maximum number of passengers to be carried in accordance with BS 5655-6, BS 5655-11, BS EN 81-20, SS 550 or equivalent.
Upgrade the control system, braking, and motor types. A micro-processor controller will electronically monitor and control motor rotation to ensure that the elevator car accurately stops at floor level. Review levelling of car to ensure the value is acceptable by standards to avoid risk of passengers tripping and falling (e.g., wheelchair users).
Permit to operate (PTO) to be displayed in the lifts.
Measure ride quality of elevators in accordance with BS ISO 18738.
Faulty door operation

The elevator inner doors failed to close completely during operation (Photo credit: Ben Tng, 2016)

Jammed elevator doors do not close completely
The gap for the elevator car doorway should not exceed 12 mm, and the clearance between elevator car door panels should be less than 10 mm. The elevator car should not make any movement if the car doors and landing doors are not properly closed and locked.
Durable materials for the doors and more durable materials for their frames (e.g. metals) should be used in accordance with BS 5655-6, BS 5655-11, BS EN 81-20, SS 550 or equivalent.
Elevator car and landing doors should be tested to withstand an impact that is similar to the impact when a person collides with the door at running speed in accordance with BS EN 81-20 or equivalent.
The main guiding elements of door should operate as intended. Doors should include retainers to keep the door panels in place in accordance with BS EN 81-20 or equivalent.
Partially-closed door should open (if button controlling door opening is pressed); while the door should remain open when the door open button is pressed.
Inspect elevator door and guides, shoes, and tracks. It should not show any permanent deformation or elastic deformation not greater than 15 mm (when force of >300 N is applied to 5 cm2 area at centre of door panels at a right angle) in accordance with BS 5655-6, BS 5655-11, BS 7255, BS EN 13015, SS 550 or equivalent.
Review the service call frequency for the door. Increased service calls signify the need to upgrade/replace door operators.