CONTENTS (cont)
Page
• COOLER PUMP CONTROL
• CONDENSER PUMP CONTROL
Cooler Heater Control .......................13
Keypad and Display Module
(Also Called HSIO-II) ......................13
• ACCESSING FUNCTIONS
AND SUBFUNCTIONS.......................13
• AUTOMATIC DEFAULT DISPLAY.............13
• STATUS FUNCTION .........................16
• TEST FUNCTION ...........................25
• HISTORY FUNCTION........................25
• SET POINT FUNCTION ......................25
• SERVICE FUNCTION ........................30
• SCHEDULE FUNCTION......................37
Temperature Reset ..........................39
• EXTERNAL TEMPERATURE RESET
• EXTERNALLY POWERED RESET
• RETURN FLUID TEMPERATURE RESET
Demand Limit ...............................39
• DEMAND LIMIT
• EXTERNALLY POWERED DEMAND LIMIT
• DEMAND LIMIT (CCN Loadshed Controlled)
TROUBLESHOOTING ......................43-52
Checking Display Codes ....................43
Unit Shutoff ................................43
Complete Unit Stoppage .....................43
Single Circuit Stoppage .....................43
Restart Procedure ...........................43
• POWER FAILURE EXTERNAL TO THE UNIT
Alarms and Alerts ...........................43
Compressor Alarm/Alert Circuit ..............43
EXD Troubleshooting Procedure .............50
• INSPECTING/OPENING ELECTRONIC
EXPANSION VALVES
• INSPECTING/OPENING ECONOMIZERS
SERVICE ..................................52-66
Servicing Coolers and Condensers ..........52
• TUBE PLUGGING
• RETUBING
• TIGHTENING COOLER/CONDENSER
HEAD BOLTS
Inspecting/Cleaning Heat Exchangers ........53
• COOLERS
• CONDENSERS (30HX Only)
Water Treatment ............................53
Condenser Coils (30GX Only) ................53
• COIL CLEANING
Condenser Fans (30GX Only) ................54
Refrigerant Charging/Adding Charge .........54
Oil Charging/Low Oil Recharging ............55
Oil Filter Maintenance .......................56
• REPLACING THE EXTERNAL OIL FILTER
• REPLACING THE INTERNAL OIL FILTER
Compressor Changeout Sequence ...........56
• BURNOUT CLEAN-UP PROCEDURE
Moisture-Liquid Indicator ....................58
Filter Drier ..................................58
Liquid Line Service Valve ....................58
Thermistors ................................58
• LOCATION
• THERMISTOR REPLACEMENT
Pressure Transducers .......................59
• PRESSURE TRANSDUCER CALIBRATION
• TROUBLESHOOTING
Safety Devices ..............................62
• COMPRESSOR PROTECTION
• OIL SEPARATOR HEATERS (30GX)
• COOLER PROTECTION
Relief Devices ..............................62
• PRESSURE RELIEF VALVES
Control Modules ............................64
• PROCESSOR MODULE (PSIO-1), HIGH VOLTAGE
RELAY MODULE (DSIO-HV), AND EXV DRIVER
MODULE (DSIO-EXV), 12/6 MODULE (PSIO-2)
• RED LED
• GREEN LED
Carrier Comfort Network (CCN) Interface .....64
• PROCESSOR MODULE (PSIO-1)
• HIGH VOLTAGE RELAY MODULE (DSIO-HV)
Replacing Defective Processor Module .......66
Winter Shutdown Preparation ................66
PRE-START-UP PROCEDURE ................67
START-UP AND OPERATION .................67
FIELD WIRING ............................68-73
APPENDIX A
(Compressor Must Trip Amps) ...........74-76
APPENDIX B
(Capacity Loading Sequence) ............77-79
APPENDIX C (Available Accessories) .........80
APPENDIX D (CPM Configurations) .........81-85
APPENDIX E (Cooler and
Condenser Pressure Drop) ...............86-88
APPENDIX F
(Typical System Components) ............89,90
INDEX ......................................91
START-UP CHECKLIST ..............CL-1 to CL-8
GENERAL
IMPORTANT: The 30GX/HX units use refrigerant
R-134a. Compressor oil used with R-134a is Polyo-
lester oil.
This publication contains Start-Up, Service, Controls,
Operation and Troubleshooting data for the 30GX080-265
and 30HXA,C076-271 screw chillers.
Circuits are identified as circuits A and B, and compres-
sors are identified as A1 or A2 in circuit A, and B1 in
circuit B.
The 30GX/HX Series chillers feature microprocessor-
based electronic controls and electronic expansion devices
(EXD) in each refrigeration circuit.
The control system cycles compressor loaders and/or com-
pressors to maintain the selected leaving fluid temperature
set point. The system automatically positions the EXD to
maintain the specified refrigerant level in the cooler. The sys-
tem also has capabilities to control a condenser water valve
to maintain suitable leaving-water temperature for the 30HXC
unit. Safeties are continuously monitored to prevent the unit
from operating under unsafe conditions. A scheduling func-
tion can be programmed by the user to control the unit’s oc-
cupied and unoccupied schedules. The control also operates
a test function and a manual control function that allows the
operator to check output signals and ensure components are
operable.
The control system consists of a processor module
(PSIO-1), an EXD driver module (DSIO-EXV), a high volt-
age relay module on 30GX units (DSIO-HV), 2 six-pack re-
lay boards, a keypad and display module (also called HSIO-
II), 2 electronic expansion devices (EXDs), 1 compressor
protection module (CPM) per compressor, a PSIO-2 mod-
ule, 6 thermistors, and 8 transducers. Aremote enhanced dis-
play is available as an accessory.
2
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