English
Page 23
6
OPERATION
The units SLS/SLH are equipped with a microproces-
sor control logic and regulation management sys-
tem.
The system consists of a unit logic board and a liquid
crystal control panel which manages the control,
starting, shutdown and display functions.
6.1 General Informations
h
Introduction
The information and the operating instructions of the
electronic control system mounted on the unit are list-
ed here below.
h
Main characteristics
– Microprocessor control
– User friendly easy reachable keyboard
– Proportional – Integral control of return water tem-
perature (RWT)
– Hysteresis type control of leaving chilled water tem-
perature (LWT)
– Access code to Service Level
– Acoustic and LED alarm indication
– Backlighted liquid crystals display
– Closed loop condensing pressure control
– Start and stop pump down logic
– Cooling capacity steps rotation
-–Oil recovery function
– Night (or Double set point) function management
– Compressor and pump working hours meter
– Discharge and suction pressure display
– Memorized alarms history
– 4 set point time programs
Possibility to connect:
– Serial Communication Card RS485: to connect the
Chiller Control
to a BMS (Carel or Modbus type)
– Remote Display Terminal
– Remote control
– Phase monitoring kit
– Black Box
h
“Chiller Control” system for SLS/H
two screw compressors units
These cooling only water chillers are provided with a
microprocessor board having a default program for
the management of two refrigeration circuits each
one equipped with one twin screws compressor, one
low pressure transducer and one high pressure trans-
ducer. The control system consists of:
- INTERNAL ELECTRONIC PCB
- TERMINAL UNIT WITH DISPLAY AND KEYBOARD
- CHILLED FLUID TEMPERATURE SENSORS
- AMBIENT AIR TEMPERATURE SENSORS
- COIL TEMPERATURE SENSORS
- HIGH PRESSURE TRANSDUCER
- LOW PRESSURE TRANSDUCER
6.2 Keyboard – Display Terminal Unit
h
General Information
The figure which follows shows the terminal unit with
open access door.
On the figure it is possible to see the microprocessor
managed 4 lines – 20 columns LCD display, the key-
board and the LEDs which allow to program all the
control parameters as setpoints, differential band,
alarm thresholds and to perform the main functions.
Operation
h
Keyboard
The terminal unit allows the operator to perform the
following operations:
– initial configuration of the unit
– modification of the main working parameters
– displaying of the alarms and their notification by
“buzzer”
– displaying of all the measured parameters.
Manuale SLS-SLH1 2.8.2005 12:34 Pagina 23
