Article 9- The Benefits of Using Inverter (VVVF) in Escalators
The advantages of an inverter (VVVF) in escalators and moving walks
In this section, we intend to describe the mechanical and electrical advantages of using an inverter (Variable Voltage Variable Frequency) in escalators.
Advantages of Inverter in escalators at the time of switching on and off
In escalators and moving walks with the inverter option, the voltage and the frequency increase gradually at a pre-defined acceleration. When the escalator is switched on, the inverter provides a controlled regulated voltage to the motor drive and this causes a smooth start. Therefore, the main chains and other main components do not face a sudden forced movement, which increases their life cycle significantly. It also prevents a sudden stopping when it gets switched off, which can decrease the danger of passengers falling.
Advantages of Inverter in escalators operation modes
The inverter allows the possibility of using the device in different operation modes. For example, during the operation, if nobody uses the escalator, after a specified time the device speed will automatically decrease to 40% of the nominal speed which is called “Standby Mode”. Also, it can be set in a way that if not used for a long time, the device stops completely which is called “Stop Mode”. In both modes when a passenger passes through the photoelectric sensor located at the entry landing, the device begins to reach the nominal speed.
Detection sensor of escalator VVVF option
The sensor, called “Photoelectric Sensor”, has the task of detecting passenger entry into the escalator. The photoelectric sensor is of two types. The first type is the Beam Sensor which can be installed on two poles and detects the passengers before they enter the landing area, or it can be pole-less and installed on the skirt panel, before the comb intersection line which detects the passengers at the same time as they step on to the horizontal steps of moving area. In the pole-less type, because the distance between the beam sensor and moving area is short, the passengers feel the acceleration when the escalator reaches nominal speed.
The second type is the Microwave Sensor which is normally located on the handrail entrance and can detect passengers on the landing before they arrive at the moving area. In this type of sensor, because the distance between the detection area and moving area is not short, the passenger does not feel the acceleration when the escalator reaches the nominal speed.
Advantages of Inverter in escalators power consumption
By controlling the voltage and frequency, the inverter creates various speeds, and as a result, it causes a significant reduction in power consumption. Without the inverter option, the power consumption will increase three to four times more during operations and especially when switching on.