3
Graphic controller
3.1
Controller
View of the AIRLOGIC² controller
Introduction
The electronic controller has following functions:
• Controlling the compressor
• Protecting the compressor
• Monitoring components subject to service
• Automatic restart after voltage failure
Automatic control of the compressor
The controller maintains the net pressure between programmable limits by automatically loading and
unloading the compressor (fixed speed compressors) or by adapting the motor speed (compressors with
frequency converter). A number of programmable settings, e.g. the unloading and loading pressures (for fixed
speed compressors), the setpoint (for compressors with frequency converter), the minimum stop time and the
maximum number of motor starts and several other parameters are taken into account.
The controller stops the compressor whenever possible to reduce the power consumption and restarts it
automatically when the net pressure decreases. If the expected unloading period is to short, the compressor
is kept running to prevent too short stand-still periods.
A number of time based automatic start/stop commands may be programmed. Take into
account that a start command will be executed (if programmed and activated), even after
manually stopping the compressor.
Protecting the compressor
Shut-down
Several sensors are provided on the compressor. If one of the measured signals exceeds the programmed
shutdown level, the compressor will be stopped.
Instruction book
2920 7101 21
17
Summary of Contents for QGS 40
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