Elevators, Escalators, and Moving Walks
Elevator and escalator inspection is dominated by functional tests and by the annual periodic cycle. Expect questions on balancing coefficient, governor/safety-gear linkage, door locking, and escalator geometry and stopping distances.
Elevators - cycle and key tests
Periodic inspection every year; supervisory inspection on installation, alteration and major repair. Critical test items:
- Balancing coefficient measured by the current method: plot up and down current against load, the crossing point is the coefficient, which must fall in 0.40–0.50 of rated load.
- Governor and safety gear linkage test at rated speed; governor action speed verified on a bench, typically every 2 years.
- Brake setting and braking force; traction capability; unintended car movement protection where fitted.
- Door locking: mechanical engagement plus electrical contact, verified for every landing.
- Buffers, overspeed/overrun protection, car and counterweight clearances, suspension rope condition and termination, overload function, emergency rescue procedure and communication.
Escalators and moving walks
Inclination not exceeding 30°, except up to 35° where rise ≤6 m and nominal speed ≤0.5 m/s. Nominal speed not exceeding 0.75 m/s. Step width 0.6, 0.8 or 1.0 m. Where rise exceeds 6 m an additional brake is required. Test items include braking distance within the specified band under defined load, comb-plate and skirt-guard protection, handrail entry guards, non-reversing protection, step sag and missing-step protection, and handrail speed synchronisation.
Worked example
A passenger escalator has rise 8 m and nominal speed 0.5 m/s. Reasoning: rise >6 m, so the 35° concession does not apply - maximum inclination is 30°; an additional brake is mandatory; measure braking distance under no-load and full-load conditions against the standard's band for this speed. Also verify non-reversing protection and handrail entry switches, which are the most commonly defeated devices in service.
Traps that cost marks
Mixing the elevator annual cycle with the 2-year lifting-appliance cycle; accepting a balancing coefficient of 0.45 quoted from memory without the measurement curve; overlooking the additional brake above 6 m rise.