Quincy Compressor QGD 40, Instruction Book

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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 too
short, the compressor is kept running to prevent too short standstill 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
Shutdown
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
26 2920 7190 02