Product data

Controls
Microprocessor controls
Microprocessor controls provide the safety, interlock, ca-
pacitycontrol and indications necessaryto operate the chiller
in a safe and efficient manner.
Control system
The microprocessor control on each Carrier 23XL screw
chiller is factory mounted, wired, and tested to ensure chiller
protection and effective capacity control. In addition, the
program logic ensures proper starting, stopping and recy-
cling of the chiller and provides a communication link to
the Carrier Comfort Network (CCN).
Features
Control system
Component Test and Diagnostic Check
Menu-Driven Keypad Interface for Status Display, Set Point
Control, and System Configuration
CCN Compatible
Automatic 2 Chiller Lead/Lag with Integral
Standby Controls
Primary and Secondary Status Messages
Individual Start/Stop Schedules for Local and
CCN Operation Modes
Recall of Up to 25 Alarm/Alert Messages with
Diagnostic Help
Safety cutouts
Each of these protective limits shall require manual reset
and cause an alarm message to be displayed on the LCD
screen informing the operator of the shutdown cause.
Motor High Temperature*, †
Refrigerant (Condenser) High Pressure*, †
Refrigerant (Cooler) Low Temperature*, †
Lube Oil Low Pressure
Lube Oil Sump Level
Compressor (Refrigerant) Discharge Temperature*
Under Voltage**
Over Voltage**
Cooler and Condenser Water Flow††
Motor Overcurrent†
Motor Acceleration Time
Intermittent Power Loss
Compressor Starter Fault†
Low Discharge Superheat Temperature
(Frame 1 and 2 Machines)
Excessive Starter Transition Time
Lack of Motor Current Signal
Motor Power Supply Phase Reversal
Temperature Sensor and Transducer Faults
Single Cycle Dropout**
Motor Miswired
Capacity control
Leaving Chilled Water Control
Entering Chilled Water Control
Soft Loading Control by Temperature or Load Ramping
Slide Valve Actuator Module
Hot Gas Bypass Valve (Optional)
Power (Demand) Limiter
Auto. Chilled Water Reset
Interlocks
Manual/Automatic Remote Start
Starting/Stopping Sequence
Pre-Flow/Post-Flow
Compressor Starter Run Interlock
Pre-Start Check of Safeties and Alerts
Low Chilled Water (Load) Recycle
Monitor/Number Compressor Starts and Run Hours
Manual Reset of Safeties
Indications
Chiller Operating Status Messages
Power-On
Pre-Start Diagnostic Check
Compressor Motor Amps
Pre-Alarm Alert
Alarm
Contact for Remote Alarm
Safety Shutdown Messages
Elapsed Time (Hours of Operation)
Chiller Input kW \
*These can be configured by user to provide alert indica-
tion at user-defined limit.
†Override protection: Causes compressor to first unload
and then, if necessary, shut down.
**Will not require manual reset or cause an alarm if auto-
restart after power failure is enabled.
††Required: Field or factory supplied flow switch (installed
at jobsite).
\ With optional kW transducer.
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