The Misconception

Escalators play an essential function in commercial facilities and public transportation locations. They operate continuously providing easy accessibility to all parts of the business site.

Typically each escalator strip is equipped with a 7.5 – 15KW inductive AC motor, which operates long hours and consumes a significant amount of electricity. The solution of using sensors for “intermittent” or “sleep” modes to reduce energy consumption has very limited applicability. This approach is not suitable for shopping malls and department stores, where escalators are in constant use, leaving no opportunity for long enough “intermittent” intervals to generate reasonable savings. And, in fact, slowing or stopping escalators will actually cause a negative customer experience and poor perception of the business.

A similar situation occurs in busy public transportation sites, such as subways and train stations, where people are continuously entering and exiting the station. These conditions force escalators to be in constant motion, nearly without any ‘intermittent’ intervals where energy savings can be implemented by the stopping or slowing down the escalators.

The solutions for changing escalator mode do not meet the market requirements to save energy.

The Right Approach

The typical design of AC motors for escalators assumes the worst-case scenario, whereby an escalator is fully loaded, which may be with two riders per step. Realistically the fully loaded scenario is seldom the case, since escalators usually operate with fewer riders.  As a result, the escalator motor are partially loaded and in this mode they are inefficient, wasting energy, with high copper and iron losses, and a low Power Factor.

The efficiency of partially loaded AC motors can be improved and losses can be decreased by reducing the voltage level supplied to the motor.  

PowerSines has developed the new generation of motor controllers (SinuMEC) that enable improving the energy efficiency of escalators without changing its speed or stopping it. 

• Click here to learn how SinuMEC provides the ideal solution for escalator motors
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