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General Description
7.9 “Chiller Control”
The “Chiller Control” unit consists of an expandable
interface card and a controller.
The function of the expandable interface card is to
monitor the inputs and control the outputs:
h
Digital inputs, such as alarm and control signals.
h
Analog inputs, such as temperature/pressure mea-
suring signals.
h
Digital outputs for exciting the control relay and
the remote-control switch.
The microprocessor will execute the logic that con-
trols:
h
The LED and the display of the alarm signals and
the operation of the appliance.
h
The compressor’s start-up logic (excitation of the
winding and stop), potential regulation (3+3
steps).
h
The display of the compressor’s working hours
and the temperature of the water to the evapora-
tor.
h
The anti-cycling and delay timing upon start-up.
h
The automatic advance/delay sequence for the
compressor start-up.
h
The fan stop.
Reference and parameter control:
h
User level: the operator can modify any data with
the ‘ENTER’, ‘+’ and ‘-’ keys.
h
Service level: password protected access by the
authorised personnel.
7.10 Accessories
List of the available accessories, supplied separately,
to be mounted on-site by the installer:
Water flow meter
Prevents the operation of the unit if the circulating
chilled fluid is insufficient. It is recommended to in-
stall a flow meter to ensure the correct operation of
the unit.
Water filter
Filter to be mounted on the suction side of the water
heat exchanger.
Remote wall terminal
Makes it possible to control the unit through the re-
mote terminal, up to a maximum distance of 200 me-
ters.
Chiller black box
Records continuously the essential thermodynamic
operating parameters, during the 10 minutes that
precede the last alarm.
Modem GSM
Makes it possible to check the working mode or the
switching on/off of the unit via SMS. In case of any
alarms, the unit sends an SMS to the user.
RS-485 MODBUS serial card
A communication interface allows you to control and
manage the unit from a local station, with RS485
connection, up to a distance of 1000 m.
It is therefore possible to obtain remote control and
management by integrating these functions into the
building’s control system.
External hydronic kit
Hydronic kits consisting of pumps and storage tanks
(1,000 to 1,500 litres).
Single Point supply box
This accessory is available for SLS 3804-4004 and
SLH 2804-3204-3604-3804 twin units, and makes
it possible to obtain only one power supply point.
Manuale SLS-SLH1 6.9.2005 10:59 Pagina 33
