International English | Real Applications |
7.3Controlling Lift Door Operation
Lift doors need to close at varying speeds. Starting slowly, accelerating fast and slowing again as they approach closure. In this case, the doors are held closed by the motor running at low frequency at zero speed. The load can vary considerably due to mechanical changes as the lift moves, and variations in door weight as external doors are operated as well. A very good result has been obtained using micro switches to select the various speeds.
7.3.1Advantages
·Very simple system provides the desired speed profile. Doors operate smoothly and silently.
·Torque at zero speed holds doors closed.
·Speed profile can be easily adjusted.
7.3.2System Specification
Motor | 4 pole 80 W 230 V |
| cooling fan - allowing zero speed operation |
Control | Two Microswitches selecting fixed frequencies; open/close signal on |
System | third digital input |
Drive | MICROMASTER MM420 750 W 230 V |
Note.
The following diagrams and tables refer to settings and parameters used on MICROMASTER MM420. Settings for MICROMASTER MM440 may be different.
Sensors
Door to Close
Door Closes Fast | DIN 1 | DIN 2 | DIN 3 | Output | Function | |
Sensor 1 | Sensor 2 | Open/Close |
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| 0 | 0 | 1 | 5 Hz | Close Slow | |
| 1 | 0 | 1 | 25 Hz | Close Fast | |
| 1 | 1 | 1 | 10 Hz | Slow Down | |
Door Slows | 0 | 1 | 1 | 2 Hz | Hold Closed | |
0 | 1 | 0 | - 6 Hz | Open Slow | ||
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| 1 | 1 | 0 | - 15 Hz | Open Fast | |
| 1 | 0 | 0 | - 5 Hz | Slow Down | |
| 0 | 0 | 0 | Stop | Stop Open | |
Door Closed |
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Figure
MICROMASTER Applications Handbook | 39 |