Chapter 2 Installation and Wiring
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2 DetectionPrinciple
1） Overspeed protection function
By measuring the speed of the driving chain sprocket through sensor A and sensor B, the
MCTC-PES-E1 system judges whether the running speed of the escalator/moving walkway
exceeds the allowable speed. If yes, the MCTC-PES-E1 system will perform overspeed
protection.
When the driving chain sprocket rotates, every time a sensor detects a tooth, the sensor
sends a pulse. The MCTC-PES-E1 system calculates the running speed of the escalator/
moving walkway based on the time interval of detected pulses.
Sensor A and sensor B are redundant speed measuring channels for each other. By setting
a certain pulse cycle or frequency threshold, 1.2 times or 1.4 times overspeed can be
detected.
2） Unintentional reversal protection
By fixing the relative positions of the two sensors correctly, make the phase of sensor A in
advance of the phase of sensor B and ensure that the two sensors have overlapping pulse
part. In this case, the MCTC-PES-E1 system detects the logic sequence of the two sensors
and judges the actual running direction of the escalator/moving walkway through the logic
sequence, preventing reversal running.
2.2.3 Installing the Handrail Speed Sensor
1 Installation
1） Installation position
Align the sensor with the inductive part on the tachometer wheel.
If the tachometer wheel is made of plastic, use a ferric device as the inductive part. If the
tachometer wheel is ferric, drill a hole as the inductive part in the wheel. The section size of
the inductive part should be approximate to that of the sensing face of the sensor.
2） Installation distance
1 mm ≤ L3 = L4 ≤ 4 mm
The following figure shows the installation position of the handrail speed sensor.
Sensor 3/4
L
3
/
4
Sensor 3/4
Sensor 3/4 signal
Tachometer wheel
Inductive part
Handrail
Figure 2-4 Installation position of the handrail speed sensor
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