APPLIANCES AND EQUIPMENT
Energy Optimiser for Lifts & Escalators
The energy optimiser is a solid-state voltage controller that reduces losses in AC induction motors by way of voltage reduction and soft starting capability. It provides the required motor operating voltage to suit various loading conditions, resulting in higher power factor (i.e. better power efficiency) and reduced motor losses. Its soft starting feature also lowers excessive starting current and prevents wearing of mechanical gears, chains, belts etc. associate with the mechanical transmission system. This technology is particularly suitable to motors with substantial variation in loading such as escalator and passenger conveyers.
An example of a motor fitted with energy optimiser
A comparison in starting current between soft start and hard start
The amount of energy saving due to energy optimiser depends heavily on the actual load of the escalator. Based on measurement of a retrofit system in North Point Government Offices in 2000 carried out by EMSD, the average energy saving could be up to 10% by using a 7.5 kW energy optimiser.
An energy optimiser (7.5 kW) retrofitted to an escalator in North Point Government Offices.
References:
- [1] Lee LT, Lam KK, Wu MKT. Application of innovative technologies for enhancing energy efficiency in Hong Kong, China.
- [2] Hong Kong Energy Efficiency Net, EMSD