SystemAir AQVC 105, Installation And Maintenance Manual

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Page 23
English
Control
6 GENERAL INFORMATION
Introduction
This document contains the information and the oper-
ating instructions for AQVL-AQVH-AQVC 4 compres-
sors & electronic control.
This information is for the after-sales service and the
production operators, for the end-of-line testing.
Main characteristics
– microprocessor control
– user-friendly keyboard
– proportional and integral control of the return
water temperature (RWT)
– hysteresis control of the leaving water temperature
(LWT)
– access code to enter the Manufacturer’s Level
– access code to enter the Service Level
– alarm and LED
– backlighted LCD
– rotation of the compressor operation
– oil return function
– night mode (or Low Noise) control
– counting of the pump/compressors’ hours of
operation
– display of discharge and suction pressure values
– display of temperature sensor
– history of stored alarms (option)
– programming of different setpoints with 4 ranges
of time/setpoint.
The following accessories can be also connected:
– remote display terminal
– wire remote control.
6.1 Control of AQVL-AQVH-AQVC
with 4 compressors.
The “CHILLER CONTROL” system
The AQVL-AQVH machines with 4 scroll compressors
are provided with a microprocessor card which is fully
programmed by default for the control of a chiller with
2 circuits, 2 compressors per circuit, a high-pressure
transducer per circuit.
The control system consists of:
Keyboard & Display Terminal
General information
The figure shows the terminal with the front door open.
It is provided with a LCD 8 lines x 22 columns, key-
board and microprocessor-controlled LED’s, so as to
allow the programming of the control parameters (set-
point, differential bands, alarm thresholds) and the
main operations to be carried out by the user.
Terminal & Key Board description
The terminal makes it possible to carry out the follow-
ing operations:
– the initial configuration of the machine
– the change of all the main operating parameters
– the display of the detected alarms
– the display of all the measured quantities
The terminal and the card are connected by a 6-way
phone cable.
The connection of the terminal to the basic card is not
essential for the normal operation of the controller.