York YCAS0295EB Owner's manual

INSTALLATION, OPERATION & MAINTENANCE
AIR-COOLED SCREW LIQUID CHILLERS
New Release Form 201.19-NM7 (804)
YCAS AIR-COOLED LIQUID CHILLERS
YCAS0295EB THROUGH YCAS0605EB
STYLE G R-407C
50 HZ
YCAS 2 SYSTEM EPROM 031-01798-001 (STANDARD, BRINE & METRIC MODELS COMBINED)
028971-G
035-20885-000

2YORK INTERNATIONAL
FORM 201.19-NM7 (804)
CHANGEABILITY OF THIS DOCUMENT
In complying withYORK’s policy for continuous product improvement, the information contained in this document
is subject to change without notice. While YORK makes no commitment to update or provide current information
automatically to the manual owner, that information, if applicable, can be obtained by contacting the nearest YORK
Engineered Systems Service office.
It is the responsibility of operating/service personnel to verify the applicability of these documents to the equip-
ment in question. If there is any question in the mind of operating/service personnel as to the applicability of these
documents, then prior to working on the equipment, they should verify with the owner whether the equipment has
been modified and if current literature is available.

3
YORK INTERNATIONAL
FORM 201.19-NM7 (804)
This equipment is a relatively complicated apparatus.
During installation, operation, maintenance or service,
individuals may be exposed to certain components or
conditions including, but not limited to: refrigerants,
oils, materials under pressure, rotating components, and
both high and low voltage. Each of these items has the
potential, if misused or handled improperly, to cause
bodily injury or death. It is the obligation and respon-
sibility of operating/service personnel to identify and
recognize these inherent hazards, protect themselves,
and proceed safely in completing their tasks. Failure
to comply with any of these requirements could result
in serious damage to the equipment and the property in
IMPORTANT!
READ BEFORE PROCEEDING!
GENERAL SAFETY GUIDELINES
which it is situated, as well as severe personal injury or
death to themselves and people at the site.
This document is intended for use by owner-authorized
operating/service personnel. It is expected that this in-
dividual possesses independent training that will enable
them to perform theirassigned tasks properly andsafely.
It is essential that, prior to performing any task on this
equipment, this individual shall have read and under-
stood this document and any referenced materials. This
individual shall also be familiar with and comply with
all applicable governmental standards and regulations
pertaining to the task in question.
SAFETY SYMBOLS
The following symbols are used in this document to alert the reader to areas of potential hazard:
CAUTION identifies a hazard which
couldleadtodamagetothemachine,
damage to other equipment and/or
environmental pollution. Usually
an instruction will be given, together
with a brief explanation.
NOTE is used to highlight additional
information which may be helpful to
you.
DANGER indicates an imminently
hazardous situation which, if not
avoided,willresultindeathorserious
injury.
WARNING indicates a potentially
hazardous situation which, if not
avoided, could result in death or se-
rious injury.
External wiring, unless specified as an optional connection in the manufacturer’s product
line,is NOT tobe connected insidethe micro panelcabinet. Devices suchas relays, switches,
transducers and controls may NOT be installed inside the micro panel. NO external wiring
is allowed to be run through the micro panel.All wiring must be in accordance with YORK’s
publishedspecifications and mustbe performed ONLYbyqualifiedYORK personnel.YORK
will not be responsible for damages/problems resulting from improper connections to the
controls or application of improper control signals. Failure to follow this will void the
manufacturer’s warranty and cause serious damage to property or injury to persons.

4YORK INTERNATIONAL
FORM 201.19-NM7 (804)
TABLE OF CONTENTS
SECTION 1 - GENERAL CHILLER
INFORMATION & SAFETY
INTRODUCTION ...........................................................9
WARRANTY...................................................................9
SAFETY...........................................................................9
Standards for Safety ...............................................9
RESPONSIBILITY FOR SAFETY...............................10
ABOUT THIS MANUAL..............................................10
MISUSE OF EQUIPMENT...........................................10
Suitability for Application....................................10
Structural Support ................................................10
Mechanical Strength.............................................10
General Access.....................................................10
Pressure Systems..................................................10
Electrical...............................................................10
Rotating Parts.......................................................11
Sharp Edges..........................................................11
Refrigerants and Oils............................................11
High Temperature and Pressure Cleaning............11
Emergency Shutdown...........................................11
SECTION 2 - PRODUCT DESCRIPTION
INTRODUCTION .........................................................12
General Description..............................................12
Compressor...........................................................12
Evaporator............................................................13
Condenser.............................................................13
Economizer...........................................................14
Oil Separator/System............................................14
Oil Cooling...........................................................14
Capacity Control ..................................................14
Power and Control Panel......................................14
Each power compartment contains: .....................15
The control section contains:................................15
The options sections contain:...............................15
Microprocessor Controls......................................15
Motor Current Protection .....................................15
Motor Protection Modules (2ACE)......................16
Current Overload..................................................16
Thermal Overload ................................................17
Current Imbalance (Loaded & Unloaded)............17
Loss of Phase........................................................17
Improper Phase Sequence ....................................17
MOTOR STARTING.....................................................20
KEYPAD CONTROLS..................................................20
Display .................................................................20
Program................................................................21
ACCESSORIES AND OPTIONS .................................21
Multiple Point Power Connection (Standard)......21
Single-Point Power Connection with Individual
Circuit Protection .................................................21
Single-Point Power Connection with Combined
Circuit Protection ................................................21
Single-Point Power Connection without Circuit
Protection ............................................................21
Control Circuit Terminal Block............................21
Building Automation System (BAS) Interface.....21
Condenser Coil Protection ..................................21
DX EVAPORATOR AND STARTER OPTIONS .........24
UNIT ENCLOSURES OPTIONS .................................22
FAN OPTIONS..............................................................22
SOUND REDUCTION OPTIONS................................22
VIBRATION ISOLATION ...........................................22
UNIT NOMENCLATURE ............................................23
NAMEPLATE ENGINEERING DATA ........................23
PRODUCT IDENTIFICATION NUMBER (PIN)........24
SECTION 3 - HANDLING AND STORAGE
DELIVERYAND STORAGE.......................................25
INSPECTION................................................................25
MOVING THE CHILLER ............................................25
Lifting Weights.....................................................25
UNIT RIGGING............................................................26
SECTION 4 - INSTALLATION
LOCATION REQUIREMENTS....................................27
OUTDOOR INSTALLATIONS ....................................27
INDOOR INSTALLATIONS ........................................27
LOCATION CLEARANCES ........................................27
COMPRESSOR FEET BOLT REMOVAL ...................28
VIBRATION ISOLATORS ..........................................29
Installation............................................................29
SHIPPING BRACES.....................................................29
PIPEWORK CONNECTION........................................29
General Requirements..........................................29
WATER TREATMENT..................................................30
PIPEWORK ARRANGEMENT....................................31
CONNECTION TYPES & SIZES.................................31
EVAPORATOR CONNECTIONS ................................31
Optional Flanges ..................................................31
REFRIGERANT RELIEF VALVE PIPING..................31
DUCTWORK CONNECTION .....................................31
General Requirements..........................................31
ELECTRICAL CONNECTION....................................32
POWER WIRING..........................................................32
STANDARD UNITS WITH MULTI POINT POWER
SUPPLY WIRING .........................................................32

5
YORK INTERNATIONAL
FORM 201.19-NM7 (804)
TABLE OF CONTENTS (CONT’D)
Units with Single-Point Power Supply Wiring ....32
115VAC CONTROL SUPPLY TRANSFORMER ........32
Remote Emergency Stop Device..........................33
CONTROL PANEL WIRING........................................33
VOLTS FREE CONTACTS ..........................................33
Chilled Liquid Pump Starter ................................33
Run Contact..........................................................33
Alarm Contacts.....................................................33
SYSTEM INPUTS.........................................................33
Flow Switch..........................................................33
Remote Run / Stop ...............................................33
Remote Print.........................................................33
Remote Setpoint Offset – Temperature................33
Remote Setpoint Offset – Current........................33
SECTION 5 - COMMISSIONING
PREPARATION.............................................................40
PREPARATION – POWER OFF ..................................40
Inspection .............................................................40
Refrigerant Charge...............................................40
Valves ...................................................................40
Compressor Oil ....................................................40
Fans ......................................................................40
Isolation/Protection ..............................................40
Control Panel........................................................40
Power Connections...............................................40
Grounding.............................................................40
Overloads .............................................................40
Supply Voltage .....................................................40
Control Transformer.............................................40
Switch Settings.....................................................41
Crankcase Heaters................................................41
Water System........................................................41
Flow Switch..........................................................41
Temperature Sensor(s)..........................................41
Control Supply .....................................................41
Programmed Options............................................41
Programmed Settings ...........................................41
Date and Time ......................................................41
Start/Stop Schedule ..............................................41
Setpoint and Remote Offset .................................41
FIRST TIME START-UP...............................................42
Interlocks..............................................................42
System Switches...................................................42
Start-up.................................................................42
Oil Pressure ..........................................................42
Refrigerant Flow ..................................................42
Fan Rotation.........................................................42
Suction Superheat.................................................42
Expansion Valve ..................................................42
Economizer Superheat .........................................42
Subcooling............................................................42
General Operation ................................................42
SECTION 6 - OPERATION
GENERAL DESCRIPTION..........................................44
START-UP .....................................................................44
NORMAL RUNNING AND CYCLING.......................44
SHUTDOWN.................................................................44
SECTION 7 - TECHNICALDATA
FLOW RATE AND PRESSURE DROP CHARTS.......46
GLYCOL CORRECTION FACTORS...........................46
TEMPERATURE AND FLOWS...................................47
PHYSICAL DATA.........................................................48
OPERATING LIMITATIONS AND SOUND POWER
DATA.............................................................................49
Electrical Data......................................................50
Electrical Notes ....................................................58
WIRING DIAGRAM.....................................................60
ELEMENTARY DIAGRAM.........................................62
CONNECTION DIAGRAM (SYSTEM WIRING)......73
COMPRESSOR TERMINAL BOX ..............................74
DIMENSIONS–YCAS0295-YCAS0375......................78
DIMENSIONS–YCAS0425-YCAS0575......................80
DIMENSIONS–YCAS0605..........................................82
TECHNICAL DATA......................................................84
WEIGHT DISTRIBUTIONAND ISOLATOR
MOUNTING POSITIONS ............................................85
INSTALLATION INSTRUCTIONS FOR VMC SERIES
AWR/AWMR AND CP RESTRAINED
MOUNTINGS..............................................................101
COMPRESSOR COMPONENTS...............................105
UNIT CHECKS (NO POWER)................................... 111
SYSTEM STARTUP CHECKLIST.............................111
PANEL CHECKS ........................................................112
PROGRAMMED VALUES.........................................112
INITIAL START-UP....................................................113
CHECKING SUBCOOLING AND SUPERHEAT ....113
CHECKING ECONOMIZER SUPERHEAT .............114
LEAK CHECKING.....................................................114

6YORK INTERNATIONAL
FORM 201.19-NM7 (804)
TABLE OF CONTENTS (CONT’D)
SECTION 8 - MICRO PANEL CONTENTS
CHILLER CONTROL PANEL
PROGRAMMING AND DATAACCESS KEYS.......116
DISPLAYAND STATUS INFORMATION KEYS ....116
ON / OFF ROCKER SWITCH....................................116
PROGRAM & SETUP KEYS.....................................116
1. INTRODUCTION & PHYSICAL DESCRIPTION 117
1.1 General .........................................................117
1.2 Keypad & Display........................................117
1.3 Unit (chiller) ON/OFF Switch......................118
1.4 Microprocessor Board..................................118
1.5 Ancillary Circuit Boards...............................118
1.6 Circuit Breakers ...........................................119
1.8 Transformers.................................................119
1.9 Motor Protection Modules ...........................119
1.10 EMS/BAS Controls....................................122
1.11 Microprocessor Board Layout....................124
1.12 Logic Section Layout .................................125
1.13 Anti-Recycle Timer ....................................126
1.14 Anti-Coincidence Timer.............................126
1.15 Evaporator Pump Control...........................126
1.16 Compressor Heater Control........................126
1.17 Evaporator Heater Control .........................126
1.18 Pumpdown (EEV) Control.........................126
1.19 Alarms ........................................................127
1.20 Run Status (chiller) ....................................127
1.21 Lead / Lag Compressor Selection ..............127
1.22 Economizer Solenoid Control....................128
2. STATUS KEY: GENERAL STATUS MESSAGES &
FAULT WARNINGS...............................................130
2.1 General .........................................................130
2.2 General Status Messages..............................130
2.3 Unit Warnings...............................................131
2.4 Anticipation Control Status..........................132
2.5 Unit Fault Status Messages ..........................133
2.6 System Fault (SAFETY) status ...................134
2.7 Printout on Fault Shutdown..........................137
3. DISPLAY KEYS & OPTION SWITCHES.............138
3.1 General .........................................................138
3.2 Chilled Liquid Temps key............................138
3.3 System # Data Keys .....................................139
3.4 Ambient Temp Key ......................................139
3.5 % Motor Current key....................................140
3.6 Operating Hrs / Start Counter key................140
3.7 Options key & .............................................140
3.8 Function Key................................................142
4. PRINT KEYS...........................................................143
4.1 General .........................................................143
4.2 Oper Data Key..............................................143
4.3 Operating Data – Software Version..............143
4.4 Operating Data – Remote Printout...............145
4.5 History Key ..................................................146
4.6 Fault History Data – Local Display
Messages ......................................................146
4.7 Fault History Data – Remote Printout..........150
5. ENTRY KEYS.........................................................151
5.1 General .........................................................151
5.2 Numerical Keypad........................................151
5.3 Enter Key......................................................151
5.4 Cancel Key...................................................151
5.5 !" KEYS ...............................................151
6. SETPOINTS KEYS & CHILLED LIQUID
CONTROL...............................................................152
6.1 General .........................................................152
6.2 Chilled Liquid Temperature Control............152
6.3 Local Cooling Setpoints Key .......................156
6.4 Remote cooling setpoints Key......................156
7. CLOCK KEYS ........................................................157
7.1 GENERAL ...................................................157
7.2 SET TIME KEY...........................................157
7.3 set schedule / holiday key.............................158
7.4 Manual Override key....................................159
8. PROGRAM KEY.....................................................160
8.1 General .........................................................160
8.2 Program Key – User Programmable Value ..160
8.3 Programming "Default" Values....................164
8.4 Electronic Expansion Valve..........................166
8.5 EEV Operation .............................................167
8.6 EEV Programming .......................................169
8.7 EEV Troubleshooting...................................170
8.8 Condenser Fan Control.................................171
8.9 Service Mode: Unit Setup ............................173
8.10 Sensor Calibration Charts...........................176
8.11 Control Inputs/Outputs...............................177
8.12 ISN Control ...............................................180

7
YORK INTERNATIONAL
FORM 201.19-NM7 (804)
TABLE 1 – Motor Protector Dip Switch Setting ..........18
TABLE 2 – Programmable Values Table
(minimum/maximum)...............................169
TABLE 3 – Condenser Fan Control and Fan Contactor
Data for DXST Units with 4
Fans/System.............................................172
TABLE 4 – Condenser Fan Control and Fan Contactor
Data For DXST Units With 5
Fans/System.. ...........................................172
TABLE 5 – Service Mode Programmable Values ......173
TABLE 6 – YCAS Style G, Across the Line Start .....174
TABLE 7 – YCAS Style G, Wye Delta Start .............174
TABLE 8 - Digital Outputs..........................................177
TABLE 9 - Analog Inputs............................................178
TABLE 10 - Digital Inputs ..........................................179
TABLE 11 - Analog Outputs........................................179
TABLE 12 – ISN Received Data.................................180
TABLE 13 – ISN Transmitted Data.............................180
TABLE 14 – ISN Operational and Fault Codes...........183
SECTION 9 - MAINTENANCE
GENERAL REQUIREMENTS...................................184
CONDENSER COILS.................................................184
Chiller / Compressor Operating Log..................185
Scheduled Maintenance......................................185
ON-BOARD BATTERY BACK-UP...........................185
OVERALL UNIT INSPECTION ................................185
GENERAL PERIODIC MAINTENANCE CHECKS
STANDARD UNITS .................................................188
SECTION 10 - SPARE PARTS
Recommended Spares ........................................189
Recommended Compressor Oils........................189
SECTION 11 - TROUBLE SHOOTING
TROUBLESHOOTING GUIDE.................................190
LIMITED WARRANTY YORK AMERICAS
ENGINEERED SYSTEMS.........................................192
WARRANTY ON NEW EQUIPMENT......................192
WARRANTY ON RECONDITIONED
REPLACEMENT MATERIALS.................................192
TEMPERATURE CONVERSION CHART
ACTUAL TEMPERATURES......................................193
TEMPERATURE CONVERSION CHART
DIFFERENTIAL TEMPERATURES..........................193
PRESSURE CONVERSION CHART - GAUGE
OR DIFFERENTIAL.................................................193
LIST OF TABLES
TABLE OF CONTENTS (CONT’D)

8YORK INTERNATIONAL
FORM 201.19-NM7 (804)
LIST OF FIGURES
FIG. 25 – POWER PANEL (SYSTEM #2)
COMPONENT LOCATIONS.....................70
FIG. 26 – DIMENSIONS YCAS0295 - 0375 .............78
FIG. 27 – DIMENSIONS YCAS0425- 0575.................80
FIG. 28 – DIMENSIONS YCAS0605...........................82
FIG. 29 – CLEARANCES.............................................84
FIG. 30 – CP-2-XX........................................................86
FIG. 31 – ISOLATOR DETAILS .................................87
FIG. 32 – CP-2-XX........................................................90
FIG. 33 – ISOLATOR DETAILS .................................91
FIG. 34 – CP-2-XX........................................................94
FIG. 35 – ISOLATOR DETAILS .................................95
FIG. 36– CP-2-XX.........................................................98
FIG. 37 – ISOLATOR DETAILS .................................99
FIG. 38 – REFRIGERANT FLOW DIAGRAM .........102
FIG. 39 – PROCESS AND INSTRUMENTATION
DIAGRAM..................................................103
FIG. 40 – COMPONENT LOCATIONS.....................104
FIG. 41 – COMPRESSOR COMPONENTS ..............105
FIG. 42 – COMPRESSOR COMPONENTS ..............106
FIG. 43 – COMPRESSOR COMPONENTS ..............107
FIG. 44 – COMPRESSOR COMPONENTS ..............108
FIG. 45 – COMPRESSOR COMPONENTS ..............109
FIG. 46 – COMPRESSOR COMPONENTS ..............110
FIG. 47 – MOTOR PROTECTION MODULE...........121
FIG. 48 – COMPONENT LAYOUT ...........................124
FIG. 49 – LOGIC SECTION LAYOUT......................125
FIG. 50 – PROCESS AND INSTRUMENTATION
DIAGRAM...............................................129
FIG. 51 – SUCTION PRESSURE CUTOUT .............135
FIG. 52 – ENLARGED PHOTOGRAPH OF DIP
SWITCHES ON MICROPROCESSOR
BOARD.......................................................141
FIG. 53 – ELECTRONIC EXPANSION VALVE .....166
FIG. 54 – CONDENSER FAN LAYOUT FOR
DXST 2 COMPRESSOR UNITS .............171
FIG. 1 – COMPONENT LOCATIONS.........................12
FIG. 2 – SCREW COMPRESSOR................................13
FIG. 3 – UNIT RIGGING..............................................26
FIG. 4 – LIFTING LUGS..............................................26
FIG. 5 – COMPRESSOR MOUNTING........................28
FIG. 6 –.PIPEWORK ARRANGEMENT .....................30
FIG. 7 – VICTAULIC GROOVE..................................31
FIG. 8 – FLANGE ATTACHMENTS ...........................31
FIG. 9 – POWER PANEL SECTION............................34
FIG. 10 – OPTION PANEL SECTION.........................35
FIG. 11 – LOGIC SECTION LAYOUT........................36
FIG. 12 – LOGIC SECTION LAYOUT WITH
CONTROL PANEL LAYOUT......................37
FIG. 13 – CUSTOMER CONNECTIONS....................38
FIG. 14 – CUSTOMER CONNECTIONS....................39
FIG. 16 – GLYCOL CORRECTION FACTORS..........48
FIG. 15 – FLOW RATE AND PRESSURE DROP
CHARTS........................................................46
FIG. 16 – GLYCOL CORRECTION FACTORS..........46
FIG. 17 – WIRING DIAGRAM –
ACROSS-THE-LINE START.......................61
FIG. 18 – WIRING DIAGRAM –
ACROSS-THE-LINE START.......................62
FIG. 19 – ELEMENTARY DIAGRAM –
ACROSS-THE-LINE START......................66
FIG. 20 – WIRING DIAGRAM –
WYE-DELTA START...................................64
FIG. 21 – ELEMENTARY DIAGRAM –
WYE-DELTA START...................................65
FIG. 22 – ELEMENTARY DIAGRAM –
WYE-DELTA START...................................66
FIG. 23 – POWER PANEL (SYSTEM #1)
COMPONENT LOCATIONS.....................68
FIG. 24 – CONTROL PANEL COMPONENT
LOCATION................................................69

9
YORK INTERNATIONAL
FORM 201.19-NM7 (804)
INTRODUCTION
YORK YCAS chillers are manufactured to the highest
design and construction standards to ensure high
performance, reliability and adaptability to all types of
air conditioning installations.
The unit is intendedfor cooling wateror glycol solutions
andis not suitablefor purposes otherthan those specified
in this manual.
This manual and the Microprocessor Operating
Instructions contain all the information required for
correct installation and commissioning of the unit,
together with operating and maintenance instructions.
The manuals should be read thoroughly before
attempting to operate or service the unit.
All procedures detailed in the manuals, including
installation, commissioning and maintenance tasks
must only be performed by suitably trained and
qualified personnel.
The manufacturer will not be liable for any injury or
damage causedby incorrect installation,commissioning,
operation or maintenance resulting from a failure to
follow the procedures and instructions detailed in the
manuals.
WARRANTY
York International warrants all equipment and materials
against defects in workmanship and materials for a
period of eighteenmonths from deliveryunless extended
warranty has been agreed upon as part of the contract.
The warranty is limited to parts only replacement and
shipping of any faulty part, or sub-assembly which has
failed due to poor quality or manufacturing errors. All
claims must be supported by evidence that the failure
has occurred within the warranty period, and that the
unit has been operated within the designed parameters
specified.
All warranty claims must specify the unit model, serial
number, order number. These details are printed on the
unit identification plate.
The unit warranty will be void if any modification to the
unit is carried out without prior written approval from
York International.
For warranty purposes, the following conditions must
be satisfied:
• The initial start of the unit should be carried out
by trained personnel from an Authorized YORK
Service Center. See Commissioning, page 40.
• Only genuine YORK approved spare parts, oils
and refrigerants must be used. Recommendations
on spare parts can be found on page 189.
• All the scheduled maintenance operations detailed
in this manual must be performed at the specified
times by suitably trained and qualified personnel.
See Maintenance Section, page 184.
• Failure to satisfy any of these conditions will
automatically void the warranty. See Warranty
Policy, page 192.
SAFETY
Standards for Safety
YCAS chillers are designed and built within an ISO
9002 accredited design andmanufacturing organization.
The chillers comply with the applicable sections of the
following Standards and Codes:
• ANSI/ASHRAE Standard 15, Safety Code for
Mechanical Refrigeration
• ANSI/NFPAStandard 70, National Electrical Code
(N.E.C.)
• ASME Boiler and Pressure Vessel Code, Section
VIII Division 1
• ARI Standard 550/590-98, Centrifugal and Rotary
Screw Water Chilling Packages
In addition, the chillers conform to Underwriters
Laboratories (U.L.) for construction of chillers and
provide U.L./cU.L. listing label.
GENERAL CHILLER INFORMATION & SAFETY
1

10 YORK INTERNATIONAL
FORM 201.19-NM7 (804)
RESPONSIBILITY FOR SAFETY
Every care has beentaken in the designand manufacture
of the unit to ensure compliance with the safety require-
ments listed above. However, the individual operating
or working on any machinery is primarily responsible
for:
• Personal safety, safety of other personnel, and the
machinery.
• Correct utilization of the machinery in accordance
with the procedures detailed in the manuals.
ABOUT THIS MANUAL
The following terms are used in this document to alert
the reader to areas of potential hazard.
A Warning is given in this document
to identify a hazard which could lead to
personal injury. Usually an instruction
will be given, together with a brief expla-
nation and the possible result of ignoring
the instruction.
A Caution identifies a hazard which could
lead to damage to the machine, damage to
otherequipment and/or environmental pol-
lution. Usually an instructionwill be given,
together with a brief explanation and the
possible result of ignoring the instruction.
A Note is used to highlight additional
information which may be helpful to you
but where there are no special safety impli-
cations.
The contents of this manual include suggested best
working practices and procedures. These are issued for
guidance only, and they do not take precedence over
the above stated individual responsibility and/or local
safety regulations.
This manual and any other document supplied with
the unit, are the property of YORK which reserves all
rights. They may not be reproduced, in whole or in part,
without prior written authorization from an authorized
YORK representative.
MISUSE OF EQUIPMENT
Suitability forApplication
The unit is intended for cooling water or glycol solutions
and is not suitable for purposes other than those specified
inthese instructions.Any useof the equipment other than
its intended use, or operation of the equipment contrary
to the relevant procedures may result in injury to the
operator, or damage to the equipment.
The unit must not be operated outside the design pa-
rameters specified in this manual.
Structural Support
Structural support of the unit must be provided as in-
dicated in these instructions. Failure to provide proper
support may result in injury to the operator, or damage
to the equipment and/or building.
Mechanical Strength
The unit is not designed to withstand loads or stresses
from adjacent equipment, pipework or structures. Ad-
ditional components must not be mounted on the unit.
Any such extraneous loads may cause structural failure
and may result in injury to the operator, or damage to
the equipment.
General Access
There are a number of areas and features which may
be a hazard and potentially cause injury when working
on the unit unless suitable safety precautions are taken.
It is important to ensure access to the unit is restricted
to suitably qualified persons who are familiar with the
potential hazards and precautions necessary for safe
operation and maintenance of equipment containing
high temperatures, pressures and voltages.
Pressure Systems
Theunit containsrefrigerant vapor andliquid underpres-
sure, release of which can be a danger and cause injury.
The user should ensure that care is taken during instal-
lation, operation and maintenance to avoid damage to
the pressure system. No attempt should be made to gain
accesstothecomponent partsofthe pressure systemother
than by suitably trained and qualified personnel.
Electrical
The unit must be grounded. No installation or main-
tenance work should be attempted on the electrical
equipment without first switching OFF, isolating and
locking-off the power supply. Work on live equipment
mustonly be carried out by suitably trainedand qualified
General Chiller Information & Safety

11
YORK INTERNATIONAL
FORM 201.19-NM7 (804)
personnel. No attempt should be made to gain access to
the control panel or electrical enclosures during normal
operation of the unit.
Rotating Parts
Fan guards must be fitted at all times and not removed
unless the powersupply has been isolated.If ductwork is
to be fitted, requiring the wire fan guards to be removed,
alternative safety measures must be taken to protect
against the risk of injury from rotating fans.
Sharp Edges
The finning on the air cooled condenser coils has sharp
metal edges. Reasonable care should be taken when
working in contact with the coils to avoid the risk of
minor abrasions and lacerations. The use of gloves is
recommended.
Refrigerants and Oils
Refrigerants and oils used in the unit are generally non-
toxic, non-flammable and non-corrosive, and pose no
special safety hazards. Use of gloves and safety glasses
are, however, recommended when working on the unit.
The build up of refrigerant vapor, from a leak for ex-
ample, does pose a risk of asphyxiation in confined or
enclosed spaces and attention should be given to good
ventilation.
High Temperature and Pressure Cleaning
High temperature and pressure cleaning methods (e.g.
steam cleaning) should not be used on any part of the
pressure system as this may cause operation of the pres-
sure relief device(s).Detergentsand solvents which may
cause corrosion should also be avoided.
EMERGENCY SHUTDOWN
In case of emergency the electrical option panel is fitted
with an emergency stop switch CB3 (Circuit Breaker
3). Separate Circuit Breakers, CB1 (System 1) and CB2
(System 2), can also be used to stop the respective sys-
tem in an emergency. When operated, CB3 removes the
electrical supply from the control system, thus shutting
down the unit.
1

12 YORK INTERNATIONAL
FORM 201.19-NM7 (804)
INTRODUCTION
YORK YCAS chillers are designed for water or wa-
ter-glycol cooling. All units are designed to be located
outside on the roof of a building or at ground level.
The units are completely assembled with all intercon-
necting refrigerant piping and internal wiring, ready for
field installation.
Prior to delivery, the unit is pressure tested, evacuated,
and fully charged with refrigerant and oil in each of the
two independent refrigerant circuits. After assembly,
an operational test is performed with water flowing
through the evaporator to ensure that each refrigerant
circuit operates correctly.
The unit structure is manufactured from heavy gauge,
galvanized steel.All external structural parts are coated
with “Desert Sand” baked-onenamel powder paint.This
providesa finish which, when subjected toASTM B117,
500 hour, 5% salt spray conditions, shows breakdown
of less than 1/8" either side of a scribed line (equivalent
to ASTM D1654 rating of “6”).
All exposed power wiring is be routed through liquid-
tight, non-metallic conduit.
General Description
TheAir Cooled Screw Chillerutilizes many components
which are the same or nearly the same as a standard
reciprocating chiller of a similar size. This includes
modular frame rails, condenser, fans and evaporator.
The chiller consists of 2 screw compressors in a corre-
sponding numberof separate refrigerantcircuits, asingle
shelland tube DX counterflowevaporator,economizers,
an air cooled condenser, and expansion valves.
Compressor
The semi-hermetic rotary twin-screw compressor is
designed for industrial refrigeration applications and
ensures high operational efficiencies and reliable per-
formance. Capacity control is achieved through a single
slide valve. The compressor is a positive displacement
type characterized bytwo helicallygrooved rotors which
aremanufactured fromforgedsteel.The 60Hz motorop-
erates at 3550 RPM to direct drive the male rotor which
in turn drives the female rotor on a light film of oil.
PRODUCT DESCRIPTION
FIG. 1 – COMPONENT LOCATIONS
1 System Fans
2 System 1 Power Panel
3 System 2 Power Panel
4 Control Panel
5 Power Entry
6 System 1 Compressor
7 Evaporator
8 System 2 Compressor
9 System 1 Condenser
10 Option Box
1
028971-G
Product Description
23
10
4
9
8
6
7
5

13
YORK INTERNATIONAL
FORM 201.19-NM7 (804)
Refrigerant gas is drawn into the void created by the
unmeshing of the five lobed male and seven lobed
female rotor. Further meshing of the rotors closes
the rotor threads to the suction port and progressively
compresses the gas in an axial direction to the discharge
port. The gas is compressed in volume and increased
in pressure before exiting at a designed volume at the
discharge end of the rotor casing. Since the intake and
discharge cycles overlap, a resulting smooth flow of gas
is maintained.
The rotors are housed in a cast iron compressor housing
precision machined to provide optimal clearances for
the rotors. Contact between the male and female rotor
is primarily rolling on a contact band on each of the
rotor’s pitch circle. This results in virtually no rotor
wear and increased reliability, a trademark of the screw
compressor.
The compressor incorporates a complete anti-friction
bearing design for reduced power input and increased
reliability. Four separated, cylindrical, roller bearings
handle radial loads. Angular-contact ball bearings
handle axial loads.Together theymaintain accuraterotor
positioning at all pressure ratios, thereby minimizing
leakage and maintaining efficiency. A springless check
valve is installed in the compressor discharge housing
to prevent compressor rotor backspin due to system
refrigerant pressure gradients during shutdown.
Motor cooling is provided by suction gas from the
evaporator flowing across the motor. Redundant
overload protection is provided using both thermistor
and current overload protection.
The compressor is lubricated by removing oil from
the refrigerant using an external oil separator. The
pressurized oil from the oil separator is then cooled in
the condenser coils andpiped back to thecompressor for
lubrication. The compressor design working pressure is
450 PSIG (31 bar). Each chiller receives a 300 PSIG (21
bar) low side and a 450 PSIG (31 bar) high side factory
test. A 350 watt (115-1-60) cartridge heater is located
in the compressor. The heater is temperature activated
to prevent refrigerant condensation.
The following items are also included:
• An acoustically tuned, internal discharge muffler to
minimize noise, while maintaining maximum flow
and performance.
• Discharge shutoff valve.
• A rain-tight terminal box.
• A suction gas screen and serviceable, 0.5 - 3.0
micron full flow oil filter within the compressor
housing.
Evaporator
The system uses a high efficiency Shell and Tube type
Direct Expansion Evaporator. Each of the 2 refrigerant
circuits consists of 4 passes with the chilled liquid
circulating back and forth across the tubes from one
end to the other.
The design working pressure of the standard evaporator
on the shell side is 150 PSIG (10 bar), and 350 PSIG (24
bar) for the tube (refrigerant side). The water baffles
are fabricated from galvanized steel to resist corrosion.
Removable heads are provided for access to internally
enhanced, seamless, copper tubes. Water vent and drain
connections are included.
The evaporator is equipped with a heater for protection
to -20°F (-29°C) ambient and insulated with 3/4" (19
mm) flexible closed-cell foam.
The water nozzles are provided with grooves for
mechanical couplings and should be insulated by the
contractor after pipe installation.
Condenser
The fin and tube condenser coils are manufactured
from seamless, internally enhanced, high condensing
coefficient, corrosion resistant copper tubes arranged in
FIG. 2 – SCREW COMPRESSOR
00485VIP
2

14 YORK INTERNATIONAL
FORM 201.19-NM7 (804)
staggeredrowsandmechanicallyexpandedintocorrosion
resistant aluminum alloy fins with full height fin collars.
They have a design working pressure of 450 PSIG
(31 bar). Each coil is rested to 495 PSIG (34 bar).
Multiple fans move air through the coils. They are
dynamically and statically balanced, direct drive with
corrosion resistant glass fiber reinforced composite
blades molded into low noise, full airfoil cross section,
providing vertical air discharge from extended orifices
for efficiency and low sound. Each fan is located in a
separate compartment to prevent cross flow during fan
cycling. Guards of heavygauge, PVC coatedgalvanized
steel are provided.
The fan motors are high efficiency, direct drive, 6-pole,
3-phase, Class- “F,” current overload protected, totally
enclosed (TEAO) type with double sealed, permanently
lubricated ball bearings.
Economizer
Economizeris a refrigerantto refrigerant, compactplate-
type heat exchanger to maximize chiller capacity and
efficiency by subcooling liquid refrigerant delivered to
the cooler expansion valve. Constructed of corrosion
resistant stainless steel plates formedto induce turbulent
flow and enhance heat transfer, then oven brazed and
pressure tested for reliability. Designed and constructed
withASME and TÜV certification for 31 bar (450 psig).
UL/CSA listed.
Oil Separator/System
The external oil separator, with no moving parts and
designed for minimum oil carry-over, is mounted in
the discharge line of the compressor. The high pressure
discharge gas is forced around a 90 degree bend. Oil is
forced to the outside of the separator through centrifugal
action and captured on wire mesh where it drains to the
bottom of the oil separator and flows to the condenser
for cooling before returning to the compressor.
The oil (YORK “L” oil – a POE oil used for all refrig-
erant applications), which flows back into the com-
pressor through a replaceable 0.5 - 3.0 micron oil filter,
is at high pressure. This high pressure “oil injection”
forces the oil into the compressor where it is fed to the
bearings for lubrication. After lubricating the bearings,
it is injected through orifices on a closed thread near
the suction end of the rotors. The oil is automatically
injected because of the pressure difference between the
discharge pressure and the reduced pressure at the suc-
tion end ofthe rotors.Thislubricates the rotorsas well as
provides an oil seal against leakage around the rotors to
assure refrigerant compression (volumetric efficiency).
The oil also provides cooling by transferring much of
the heat of compression from the gas to the oil keeping
discharge temperatures down and reducing the chance
for oil breakdown. Oil injected into the rotor cage flows
into the rotors at a point about 1.2x suction. This assures
that a required minimum differential of at least 30 PSID
(2.1 bar) exists between discharge and 1.2x suction, to
force oil into the rotor case. A minimum of 10 PSID
(0.6 bar) is all that is required to assure protection of
the compressor. Oil pressure safety is monitored as the
difference between suction and the pressure of the oil
entering the rotor case.
Maximum working pressure of the oil separator is 450
PSIG (31 bar). Oil level should be above the midpoint
of the “lower” oil sight glass when the compressor is
running. Oil level should not be above the top of the
“upper” sight glass.
Oil Cooling
Oil cooling is provided by routing oil from the oil sepa-
rator through several of the top rows of the condenser
coils and back to the compressor.
Capacity Control
The compressors will start at the minimum load position
and provide a capacity control range from 10% - 100%
of the full unit load using a continuous function slide
valve. The microprocessor modulates a voltage signal to
a 3-waypressure regulating capacitycontrol valvewhich
controls compressor capacity, independent of system
pressures, and balances the compressor capacity with
the cooling load. Loading is accomplished by varying
pressure through thepressure regulating capacitycontrol
valve to move the slide valve against the spring pressure
to promote stable smooth loading.
Automatic spring return of the slide valve to the min-
imum load position will ensure compressor starting at
minimum motor load.
Power and Control Panel
All controls and motor starting equipment are factory
wired and function tested. The panel enclosures are
designed to IP55 and are manufactured from powder
painted galvanized steel.
The Power and Control Panel are divided into power
sections for each compressor and associated fans, a con-
trol section and an electrical options section. The power
and control sections have separate hinged, latched, and
gasket sealed doors equipped with wind struts.
Product Description

15
YORK INTERNATIONAL
FORM 201.19-NM7 (804)
Each power compartment contains:
Compressor and fan starting contactors, fan motor
external overloads, control circuit serving compressor
capacity control, compressor andfan contactor coils and
compressor motor overloads. (Fig 1, page 12)
Current transformers in the 2ACE module provide
compressor motor overload protection and sense each
phase. This protects the compressor motors from
damage due to: low current input, high input current,
unbalanced current, single phasing, phase reversal, and
compressor locked rotor.
The control section contains:
ON/OFF switch, microcomputer keypad and display,
microprocessor board,I/O expansion board,relay boards
and power supply board.
The options sections contain:
A control circuit transformer complete with service
switch providing 115/1/60 Hz power to the unit control
system.
Electrical options as described in “Accessories and
Options.”
Microprocessor Controls
The microprocessor has the following functions and
displays:
• A liquid crystal 40 character display with text pro-
vided on two lines and light emitting diode back-
lighting outdoor viewing.
• A color coded, 35 button, sealed keypad with sec-
tions for Display, Entry, Setpoints, Clock, Print,
Program and Unit ON/OFF.
The standard controls shall include: brine chilling,
thermal storage, automatic pump down, run signal
contacts, demand load limit from external building
automationsysteminput, remote resetliquidtemperature
reset input, unit alarm contacts, chilled liquid pump
control, automatic reset after power failure, automatic
system optimization to match operating conditions.
The softwareis storedin non-volatilememory (EPROM)
to eliminate chiller failure due toAC power failure. The
Programmed Setpoints are stored in lithium battery
backed memory.
Motor Current Protection
The microprocessor motor protection provides high
current protection to assure that the motor is not
damaged due to voltage, excess refrigerant, or other
problems that could cause excessive motor current. This
is accomplished bysending a current signalproportional
tomotor current from the Motor Protectormodule to the
I/O Expansion board to be multiplexed and sent to the
Microprocessor Board. If the motor current exceeds
the 115% FLA trip point after 3 seconds of operation
on either Wye-Delta or ACL starters, the micro will
shut the system down and lock it out after one fault.
A manual reset of the respective system switch is
required to clear the fault and restart the system. A
thorough check of the motor, wiring, and refrigerant
system should be done before restarting a system that
has faulted on high motor current.
The micro also provides low motor current protection
when it senses a motor current less than 10% FLA.
The micro will shut the system down whenever low
motor current is sensed and will lock out a system if
three faults occur in 90 minutes. Low motor current
protection is activated 4 seconds after start on both
Wye-Delta and ACL starters to assure the motor starts,
the system doesn’t run without refrigerant, the motor
protector is nottripped, andthe mechanicalhigh pressure
cut-out is not tripped. Once the system is locked out
on Low Motor Current, it must be manually reset with
the system switch. See also Motor Protection Module
section below.
The micro senses low motor current whenever a HPCO
or Motor Protector contact opens. This occurs because
the MPand HPCO contacts are in series with the motor
contactor. Whenever either of these devices are open,
the contactor de-energizes and the motor shuts down.
Since the micro is sending a run signal to the contactor,
it senses the low motor current below 10% FLA and
shuts the system down.
2

16 YORK INTERNATIONAL
FORM 201.19-NM7 (804)
Motor Protection Modules (2ACE)
The mechanical motor protector is a Texas Instruments
2ACE Three Phase Protection Module (Fig. 47, page
121), provides thermal and current motor overload pro-
tection.Thismodule also protects against phase tophase
current imbalance,over current,under current, andphase
rotation. The modules, mounted in the power panels,
utilizes a 7 segment display which provides operating
status and fault diagnostic information. The 7 segment
display will display either a stationary or a flashing al-
phanumericvalue which canbe decoded bythe operator.
A list of the codes follows:
HAXXX Normal motor OFF display. Sequentially
sweeps through the motor protection dip
switch setting.
0 Normal - no fault detected (Running)
Flashing “0” Motor off or unloaded < 5A (Running)
AC current level.
1 High current fault.
2 Loaded phase to phase current
imbalance > 17%.
3 Unloaded phase to phase current
imbalance > 25%.
4 Improper incoming phase rotation.
5 High motor temperature. Trip point =
13kW, reset = 3.25kW.
6 Communication error.
7 Unload imbalance ( > 50%)
8 Phase Loss (> 60%)
E Out of range of RLA calibration.
Other symbols Defective module or supply voltage.
Working voltage 18 - 30 VAC, 24 VAC nominal.
Low voltage trip = 15 VAC.
Whenever a motor protector trips, the motor protector
contacts wired in series with the motor contacts opens
and the motor contactor de-energizes causingthe motor
to stop. The micro senses the low motor current and
shuts the system down. The micro will try two more
starts before locking the system out. The system locks
out because the motor protector is a manual reset
device. After the first start, the modules’ contacts
will be open preventing the motor contactors from
energizing. Power must be removed and reapplied to
reset the module. Use CB3 in the Micro Panel to cycle
power.
Current Overload
The 2ACE module design uses one integral current
transformer per phase to provide protection against
rapid current overload conditions. The module responds
to changes in current and must be calibrated using DIP
switches located on the module. Integral trip curves al-
low for in-rush currents during Wye-Delta, part wind,
or ACL starts without nuisance tripping.
To check the factory setting of the 2ACE module current
overload trip value. See Table 1 (pages 18 and 19).
For the location of the dip switches and determining the
ON side of the switches, refer to Figure 47, page 121.As
indicated, to place a switch in the ON position requires
pushing the switch to the left.
A switch must be pushed to the left to
place the switch in the ON position.
The numerical value for the combi-
nation of "ON" switches equals the
overload setting.
It is recommended that a YORK Ser-
vice Technician or the YORK factory
be consulted before changing these
settings for any reason, since dam-
age to the compressor could result.
Changes should never be made un-
less it is verified that the settings are
incorrect.
Anytime a dip switch change is made,
power must be cycled off and on to the
moduletoreprogram themoduleto the
new value.
Product Description

17
YORK INTERNATIONAL
FORM 201.19-NM7 (804)
Thermal Overload
ThreePTC (positivetemperature coefficient)thermistors
in the motor windings provides thermal protection. The
sensor resistance stays relatively constant at 1kΩuntil
a temperature of 266°F (130°C) is sensed. The sensor
experiences a rapid rise in resistance beyond this tem-
perature. Whenever the resistance of one of the sensors
reaches 13kΩ, +/− 3kΩ, the 2ACE module trips, which
ultimately de-energizes the motor’s pilot circuit. Reset
is manual after the motor cools and the sensor resistance
drops to 3.25kΩ, +/− 0.5kΩ.
Current Imbalance (Loaded & Unloaded)/
Loss of Phase
A 2 second delay at start-up allows for any imbalances
resulting during normal starting conditions. After this
initial delay, the 2ACE module compares the “Oper-
ating Current” to the measured half line current. The
“Operating Current” is givenby 0.65 X factoryoverload
current setting.
An unloaded compressor condition occurs when any
measured half line current is less than the “Operating
Current.” A current imbalance exceeding an unloaded
level of 25% will result in the motor pilot circuit being
de-energized.
A loaded compressor condition occurs when any mea-
sured half line current is greater than or equal to the
“Operating Current.” A current imbalance exceeding a
loaded level of 17% will result in the motor pilot circuit
being de-energized.
Imbalance is defined as
(High Phase - Low Phase)/High Phase
Improper Phase Sequence
The 2ACE module calculates the phase sequence at
start-up using the three current transformers to de-
termine whether the three phase sequence on the load
side of the main contactor is miswired. Upon detection
of a miswired motor load, the module will de-energize
the main contactor pilot circuit within 50 millisecond
response time.
Additional information on the 2ACE MP module may
be found on page 119. 2

18 YORK INTERNATIONAL
FORM 201.19-NM7 (804)
TABLE 1 – MOTOR PROTECTOR DIP SWITCH SETTING ACROSS-THE-LINE - 50 HZ
* Indicates one lead/phase through motor protector.
Product Description
Model
No. Volt. Code
Chiller
Name- -
Plate RLA
No. Leads
per Phase
Motor Protector
MP OL
Value Set Dip Switch Settings on MP
128 64 32 16 8 4 2 1
0295 50 79 1 107 0 1 1 0 1 0 1 1
0335
Sys 1 50 115 1 155 1 0 0 1 1 0 1 1
0335
Sys 2 50 79 1 107 0 1 1 0 1 0 1 1
0375 50 115 1 155 1 0 0 1 1 0 1 1
0425 50 106 1 143 1 0 0 0 1 1 1 1
0475
SYS 1 50 148 1 200 1 1 0 0 1 0 0 0
0475
SYS 2 50 106 1 143 1 0 0 0 1 1 1 1
0515 50 148 1 200 1 1 0 0 1 0 0 0
0555
SYS 1 50 188 *2 127 0 1 1 1 1 1 1 1
0555
SYS 2 50 148 2 200 1 1 0 0 1 0 0 0
0575 50 188 2 127 0 1 1 1 1 1 1 1
0605 50 173 *2 117 0 1 1 1 0 1 0 1

19
YORK INTERNATIONAL
FORM 201.19-NM7 (804)
2
* Indicates one lead/phase through motor protector.
TABLE 1 – MOTOR PROTECTOR DIP SWITCH SETTING -WYE-DETLA 50 HZ- CON'T)
Model
No. Volt. Code
Chiller
Name- -
Plate RLA
No. Leads
per Phase
Motor Protector
MP OL
Value Set Dip Switch Settings on MP
128 64 32 16 8 4 2 1
0295 50 79 2 107 0 1 1 0 1 0 1 1
0335
Sys 1 50 115 2 155 1 0 0 1 1 0 1 1
0335
Sys 2 50 79 2 107 0 1 1 0 1 0 1 1
0375 50 115 2 155 1 0 0 1 1 0 1 1
0425 50 106 2 143 1 0 0 0 1 1 1 1
0475
SYS 1 50 148 2 200 1 1 0 0 1 0 0 0
0475
SYS 2 50 106 2 143 1 0 0 0 1 1 1 1
0515 50 148 2 200 1 1 0 0 1 0 0 0
0555
SYS 1 50 188 *2 147 1 0 0 1 0 0 1 1
0555
SYS 2 50 148 *2 200 1 1 0 0 1 0 0 0
0575 50 188 *2 147 1 0 0 1 0 0 1 1
0605 50 173 *2 135 1 0 0 0 0 1 1 1

20 YORK INTERNATIONAL
FORM 201.19-NM7 (804)
MOTOR STARTING
Two types of compressor motor starting are available:
Across-the-Line and optional Wye-Delta Open Tran-
sition Starter.
Across-the-Line starters will utilize one contactor and
one start relay per compressor. The optionalWye-Delta
starter utilizes 4 motor contactors, a transition delay
relay, a start relay, and a start-wye relay.
The Wye-Delta start allows inrush current to be limited
to approximately 33% LRAfor the first 4 to 7 seconds,
with current increasing to normal running current when
the Delta connection is completed.
When the micro initiates a start signal at Relay Output
Board #1 (SYS 1) Terminal 20 or Relay Output Board
#2 (SYS 2) Terminal 20 to run a compressor, the 1CR
(SYS 1) or 2CR (SYS 2) relay is energized. The tran-
sition of the 1CR(SYS 1) or 2CR(SYS 2) relaycontacts
energizes the 1S (SYS 1) or 2S (SYS 2) relay approx.
16ms later. The 1S/2S contacts in turn energize the 1M
(SYS 1) or 3M (SYS 2) motor contacts 16ms later. This
completes the “WYE” connection of the motor start.
At the same time, the normally closed 1S/2S auxiliary
interlock contact opens preventing the 2M and 1 TRX
(SYS 1) or 4M and 2 TRX (SYS 2) motor contactors
from energizing. 2 sets of auxiliary contacts from 1M
(SYS 1) or 3M (SYS 2) close, interlocking the 1M (SYS
1) or 3M (SYS 2) contactors, keeping them energized
in parallel with 1S (SYS 1) or 2S (SYS 2).
The “WYE” connection of the motor start is enabled
for 4 to 7 seconds depending upon motor current as
sensed by the microprocessor. The transition to Delta
takes 7 seconds if current is below 110% FLA. If mo-
tor current exceeds 110% FLA, the transition is made
to Delta as long as the WYE has been enabled for at
least 4 seconds.
After the “WYE” connection is enabled for 4 to 7
seconds, the 1TR (SYS 1) or 2TR (SYS 2) transition
delay relay is enabled by the microprocessor from Relay
Output Board #1 Terminal 8 (SYS 1) or Relay Output
Board #2 Terminal 6 (SYS 2). The 1TR (SYS 1) or 2TR
(SYS 2) contacts open, de-energizing 1S (SYS 1) or 2S
(SYS 2). 1M (SYS 1) or 3M (SYS 2) remain energizes
through 2 sets of interlocking contacts 1M (SYS 1) or
3M (SYS 2). Opening of the 1TR (SYS 1) or 2TR (SYS
2) contacts deenergizes 1S/2S and closes the normally
closed 1S (SYS 1) or 2S (SYS 2) contacts, energizing
1 TR, 1 TRX, 2 TR, and 2 TRX are
NOT “timing” relays. These devices
are simply pilot relays identical to
1CR and 2CR.
KEYPAD CONTROLS
Display
Parameters are displayed in English (°F and PSIG) or
Metric (°C and Bars) units, and for each circuit, the
following items can be displayed:
• Return and leaving chilled liquid, and ambient tem-
perature.
• Day, date and time. Daily start/stop times. Holiday
and Manual Override status.
• Compressor operatinghours andstarts.Automatic or
manual lead/lag. Lead compressor identification.
• Run permissive status. No cooling load condition.
Compressor run status.
• Anti-recycle timer and anti-coincident start timer
status per compressor.
• System suction (and suction superheat), discharge,
and oil pressures and temperatures.
• Percent fullload compressormotor currentper phase
and average per phase.Compressor capacity control
valve input steps.
• Cutout status and setpoints for: supply fluid tem-
perature, low suction pressure, high discharge pres-
sure and temperature, high oil temperature, low and
high ambient, phase rotation safety, and low leaving
liquid temperature.
• Unloading limit setpoints for high discharge pres-
sure and compressor motor current.
• Status of: evaporator heater, condenser fans, load
and unload timers, chilled water pump.
• “Out of range” message.
• Up to 6 fault shut down conditions.
The standard display language is English, with 4 other
languages available.
1 TRX (SYS 1) or 2 TRX (SYS 2). 1TRX or 2TRX
subsequently energizes motor contactor 2M (SYS 1) or
4M (SYS 2), completing the “DELTA” connection of
the motor.
Product Description