MAINTENANCE AND OPERATING MANUAL
Electronic controller
HAS T 070÷140
78
ENGLISH
EN
The data in this manual are not binding and they can be modified by the manufacturer without notice. Reproduction of this manual is strictly prohibited.
6.7.20.6Remote control
The special remote control function is enabled from the display and it provides the facility to perform thermoregulation in
accordance with an external analog signal. The unit's compressors are started in a proportional manner with respect to the
value of said signal, while rotations and activation times of the compressors continue to be observed. The analog input signal
must be of the 0..10V type.
6.7.20.7Alarm contact
The special alarm contact function can be enabled from the display and it makes it possible to use an auxiliary digital output
of the electronic controller to signal a series of alarms or warnings. The digital output functions in a manner that is
independent from the standard alarm relay. The alarms and warnings that must be signalled by the digital output can be
selected on the display from the following groups:
• compressor alarms
• unit/pumps/compressors operating hours warning
• fans overload alarms
• phase-monitor alarm
• pumps overload alarm
• tank/differential pressure switch (not present)/flow switch alarms
• electronic thermostatic valves alarms
• unloading active
• defrost active
• overboost active
• faulty or open circuit probes alarms
• high/low temperatures/pressures alarms
• anti-freeze pump/heater
6.7.20.8Unit load
The special unit load function can be enabled from the display and it makes it possible to set an 0...10V analog output of the
electronic controller to indicate the percentage of the unit's cooling capacity. A signal of 0V indicates zero cooling capacity,
while 10V indicated maximum cooling capacity.
6.7.20.9Inverter pump
The special inverter pump function can be enabled at the time of configuration. An analog output of the electronic controller
detects the outlet pressure of a pump, which is then controlled by means of an inversely proportional PID regulation. The
speed of the pump decreases if the pressure rises and increases if the pressure falls. The analog input for pressure reading is
configurable between 4..20mA and 0..5V, the analog output for speed control is 0..10V.
6.7.20.10Disabling of circuits from digital inputs
The special function is enabled from the display and, by way of the digital inputs of the electronic controller it makes it
possible to control the capacity of the unit. Each circuit of the unit has a corresponding digital input that makes it possible to
enable/disable the circuit completely.
6.7.20.11Low temperature
The special low temperature function is enabled from the display and it makes it possible to edit several parameters during
low temperature operation. If the regulation temperature is lower, for a preset time, than a programmed setpoint, the values of
the following parameters are replaced with the values relative to low temperature operation:
• High pressure alarm setpoint and differential
• High pressure unloading activation setpoint
• High superheating setpoint
• PID parameters and dead zone of the solenoid valves PID control.
Modification of the parameters occurs irrespective of the unit status (On, Off, alarm, etc.) while the parameter values for
normal operation are restored if the temperature rises above the activation setpoint.
6.7.20.12Pumps for heat recovery/desuperheaters
The special function is enabled in the configuration stage and it makes it possible to control operation of one/two pumps
dedicated to heat recovery/desuperheaters. Operation of the pumps is identical to that of the unit's pumps and therefore it is
possible to program pumps rotation logic and a time lag at the time of unit shut-down.
In the presence of heat recovery, you can select on the display whether to start the pump only during the recovery demand,
with relative shut-down time lag, or always, so that the pump is always running when desuperheaters are present.
The system envisages pump overload alarms monitoring that is identical to the system used for the unit's main pumps.
To Next Page
Loading...