Retrofit

Retrofitting Strategy	Modernisation of lifts and escalators
	By applying permanent magnet (PM) gearless motor of modern technology, the efficiency of the lift hoisting machine is greatly increased, allowing for reduced energy consumption. PM machines are also lighter in weight compared with conventional geared machine systems, and more compact in size without extra accommodation for gearboxes, which is not only cost saving but also environmentally friendly without hazards of oil pollution by any chance. Advantage of maximising operational efficiency and flexibility is significant. Upgrading the escalator controller drive to variable voltage variable frequency (VVVF) drive and with the standby speed/on demand start function will maintain the escalator in stop/crawl speed until passenger is detected by the specific sensors to resume the rated speed operation. This drive system rectifies alternating current (AC) voltages from the mains supply into DC, then converts it into AC voltage with variable amplitude and frequency. The variable voltage and variable frequency enable infinitely variable speed regulation of the motor. The operation depends on the passenger flow. Significant energy can be saved when the escalator is not being occupied.
	Consideration
	All alterations need to be designed and implemented by the Registered Lift or Escalator Contractor. The cost of modernising the lift system can be high and have an unreasonable long payback period. Other benefits or need for the modernising project needs to be considered such as life cycle of the lift machine, supply of spare parts, reliability, safety and quality of services etc.
	Estimated Saving
	kW_LIFT * MLIFT * LF_LIFT * %SAVE * OPHR,yr Assume %SAVE = 55% for MGà VVVF, 35% for MGàVVAC or provided by the manufacturer Where LF_LIFT = 0.35 OPHR,yr = hr/dayday/wk52 Please click HERE to view the list of terminology.