York MILLENIUM YCAS Series Owner's manual

INSTALLATION, OPERATION & MAINTENANCE
MILLENNIUM
®
AIR-COOLED SCREW LIQUID CHILLERS
New Release Form201.18-NM6(800)
MILLENNIUM
®
YCAS AIR-COOLED SCREW LIQUID CHILLERS
YCAS0283 through YCAS0343
YCAS 2 SYSTEM EPROM 031-01798-001 (STANDARD, BRINE & METRIC MODELS COMBINED)
00397VIP(R)

2YORK INTERNATIONAL
SECTION 1GENERALCHILLER
INFORMATION&SAFETY
Introduction ............................................................... 6
Warranty ................................................................... 6
Safety ......................................................................... 6
Standards for Safety................................................6
Responsibilityfor Safety .......................................... 7
AboutthisManual ..................................................... 7
MisuseofEquipment ................................................. 7
Suitability for Application.......................................7
Structural Support ...................................................7
Mechanical Strength ...............................................7
General Access .......................................................7
Pressure Systems ....................................................7
Electrical ..................................................................7
Rotating Parts..........................................................8
Sharp Edges ............................................................8
Refrigerants and Oils ...............................................8
High Temperature and Pressure Cleaning ...............8
EmergencyShutdown ................................................ 8
MaterialSafetyData ................................................. 9
SECTION 2PRODUCTDESCRIPTION
Introduction ............................................................. 12
General Description ............................................... 12
Compressor ........................................................... 12
Evaporator............................................................. 13
Condenser ............................................................. 13
Economizer ............................................................ 14
Suction Line Heat Exchanger ................................ 14
Oil Separator / System ........................................... 14
OilCooling ............................................................ 15
Capacity Control ................................................... 15
Power and Control Panel ....................................... 15
Microprocessor Controls ...................................... 15
Motor Current Protection ......................................16
Motor Protection Module ..................................... 16
Current Overload ................................................... 17
Thermal Overload .................................................. 17
Current Imbalance ................................................. 17
Improper Phase Sequence/Loss of Phase .............17
Motor Protector Dip Switch Settings ....................18
MotorStarting ........................................................ 20
KeypadControls ...................................................... 20
Display .................................................................. 20
Entry ...................................................................... 21
Setpoints ............................................................... 21
Clock ...................................................................... 21
Print ....................................................................... 21
Program ................................................................. 21
Accessoriesand 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
ControlCircuit Terminal Block .............................. 21
Building Automation System (BAS) Interface ...... 21
Condenser Coil Protection .................................... 21
DXCoolerOptions .................................................. 22
300 PSIG (21 bar) Waterside Design Working
Pressure ................................................................. 22
1-1/2" (38mm)Insulation ...................................... 22
Flange Accessory ................................................. 22
RemoteDX Cooler ................................................. 22
Flow Switch Accessory......................................... 22
Star-Delta Compressor Motor Starter.................... 22
UnitEnclosures ....................................................... 22
Fans ......................................................................... 22
SoundReductionOptions........................................ 22
VibrationIsolation .................................................. 22
UnitNomenclatureandNameplate
EngineeringData .................................................... 23
Basic Part Number ................................................. 23
Options Section of Part Number ........................... 24
SECTION 3HANDLINGANDSTORAGE
Deliveryand Storage ............................................... 25
Inspection ................................................................ 25
MovingtheChiller .................................................. 25
Lifting Weights ..................................................... 25
UnitRigging............................................................ 26
SECTION 4INSTALLATION
LocationRequirements ........................................... 27
OutdoorInstallations .............................................. 27
IndoorInstallations ................................................. 27
LocationClearances ............................................... 27
InstallationofVibrationIsolators .......................... 28
Installation ............................................................ 28
ShippingBraces...................................................... 28
PipeworkConnection .............................................. 28
General Requirements............................................ 28
WaterTreatment ..................................................... 29
PipeworkArrangement .......................................... 30
ConnectionTypes& Sizes ...................................... 30
CoolerConnections................................................. 30
Option Flanges...................................................... 30
RefrigerantRelief ValvePiping ............................. 30
DuctworkConnection ............................................. 30
TABLE OF CONTENTS

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YORK INTERNATIONAL
FORM201.18-NM6
TABLE OF CONTENTS (CONT’D)
General Requirements............................................ 30
ElectricalConnection.............................................. 31
PowerWiring.......................................................... 31
StandardUnitswithMultiPointPowerSupply
Wiring ..................................................................... 31
Units with Single-Point Power Supply Wiring ...... 31
115VAC Control SupplyTransformer .................... 31
Remote Emergency Stop Device ........................... 32
ControlPanel Wiring ............................................. 32
VoltsFreeContacts ................................................. 32
Chilled Liquid Pump Starter................................... 32
Run Contact .......................................................... 32
Alarm Contacts ..................................................... 32
SystemInputs .......................................................... 32
Flow Switch ........................................................... 32
Remote Run / Stop ................................................ 32
Remote Print .......................................................... 32
Remote Setpoint Offset – Temperature ................. 32
Remote Setpoint Offset – Current ......................... 32
PowerandControlPanelLayouts
(Wye-DeltaTypical)................................................. 33
OptionsPanelLayout(Typical)............................... 34
LogicSectionLayout .............................................. 35
LogicSectionLayoutwith Control
PanelLayout............................................................ 36
CustomerConnections ........................................... 37
SECTION 5COMMISSIONING
Preparation ............................................................. 39
Preparation–PowerOff ......................................... 39
FirstTimeStart-up ................................................. 41
SECTION 6OPERATION
GeneralDescription................................................ 42
Start-up .................................................................... 42
NormalRunningand Cycling................................. 42
Shutdown ................................................................. 42
SECTION 7TECHNICALDATA
FlowRateand Pressure DropCharts..................... 43
GlycolCorrectionFactors ...................................... 43
TemperatureandFlows ........................................... 44
PhysicalData(SI Units) .......................................... 45
OperatingLimitations&Sound PowerData ......... 46
ElectricalData......................................................... 48
Multiple Point Power Supply Connection............. 48
Optional Single-Point Power Supply Connection
and Individual System Circuit Breakers ................ 50
Optional Single-Point Power Supply Connection
with Field Supplied Circuit Protection................... 52
Optional Single-Point Power Supply
Connection to Factory Circuit Breaker .................. 54
Compressor Data ................................................... 55
Fan Data ................................................................ 55
Electrical Notes ....................................................... 56
WiringDiagram – Across-the-LineStart ............. 57
ElementaryDiagram– Across-The-LineStart ..... 60
WiringDiagram –Wye-Delta Start ...................... 62
ElementaryDiagram–Wye-Delta Start ................ 64
PanelComponentLocations ................................... 66
ConnectionDiagram ............................................... 70
CompressorTerminalBox ...................................... 71
Dimensions ............................................................. 72
YCAS02830-0343(SI) ........................................... 72
Clearances .............................................................. 74
WeightDistributionand IsolatorMounting
Positions.................................................................. 75
InstallationInstructions forVMC Series
AWR/AWMRandCP RestrainedMountings ........ 83
Refrigerant FlowDiagram ...................................... 84
ProcessandInstrumentation Diagram .................. 85
ComponentLocations .............................................. 86
CompressorComponents ........................................ 87
SystemStart-up Checklist ..................................... 93
Unit Checks ........................................................... 93
Panel Checks ......................................................... 94
InitialStart-up......................................................... 95
CheckingSubcooling andSuperheat ..................... 95
CheckingEconomizerSuperheat........................... 96
Leak Checking ....................................................... 96

4YORK INTERNATIONAL
TABLE OF CONTENTS (CONT’D)
SECTION 8MICROPANELCONTENTS ...........................................................................................97
ChillerControl PanelProgramming andData AccessKeys...................................................97
Display and Status Information Keys ....................................................................................... 97
ON/OFF RockerSwitch ..........................................................................................................97
Program&Setup Keys .............................................................................................................97
1. INTRODUCTION&PHYSICALDESCRIPTION .................................................................................98
1.1 General ..................................................................................................................... 98
1.2 Keypad & Display................................................................................................... 98
1.3 Unit (Chiller) On / OFF Switch ................................................................................ 99
1.4 Microprocessor Board ............................................................................................ 99
1.5 Ancillary Circuit Boards .......................................................................................... 99
1.6 Circuit Breakers ......................................................................................................100
1.7 Current Transformers (C.T.) ...................................................................................100
1.8 Transformers ..........................................................................................................100
1.9 Motor Protection Modules ....................................................................................101
1.10 EMS/BAS Controls ................................................................................................103
1.11 Microprocessor Board Layout ...............................................................................105
1.12 Logic Section Layout .............................................................................................106
1.13 Anti-RecycleTimer ................................................................................................107
1.14 Anti-Coincidence Timer .........................................................................................107
1.15 Evaporator Pump Control .......................................................................................107
1.16 Compressor Heater Control....................................................................................107
1.17 Evaporator Heater Control .....................................................................................107
1.18 Pumpdown(LLSV)Control ....................................................................................107
1.19 Alarms ....................................................................................................................107
1.20 Run Status (Chiller) ................................................................................................108
1.21 Lead / Lag Compressor Selection...........................................................................108
2. STATUSKEY:GENERALSTATUSMESSAGESANDFAULTWARNINGS ......................................109
2.1 General ....................................................................................................................109
2.2 General Status Messages .......................................................................................109
2.3 Unit Warnings ........................................................................................................110
2.4 Anticipation Control Status Messages..................................................................111
2.5 Unit Fault Status Messages...................................................................................112
2.6 System Fault (Safety) Status Messages ................................................................113
2.7 Printout on Fault Shutdown...................................................................................116
3. DISPLAYKEYS&OPTIONSWITCHES............................................................................................ 117
3.1 General ....................................................................................................................117
3.2 Chilled Liquid Temps Key ......................................................................................117
3.3 System # Data Keys ...............................................................................................118
3.4 Ambient Temp Key ................................................................................................118
3.5 Motor Current Key.................................................................................................119
3.6 Operating HRS / Start Counter Key .......................................................................119
3.7 Options Key & Dip Switch Settings ......................................................................119
3.8 Function Key .........................................................................................................121
4. PRINTKEYS .......................................................................................................................................122
4.1 General ....................................................................................................................122
4.2 Oper Data Key........................................................................................................122
4.3 Operating Data – Local Display Messages............................................................122
4.4 Operating Data – Remote Printout .........................................................................123
4.5 History Key ............................................................................................................125
4.6 Fault History Data – Local Display Messages ......................................................125
4.7 Fault History Data – Remote Printout ....................................................................128

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YORK INTERNATIONAL
FORM201.18-NM6
5. ENTRYKEYS .......................................................................................................................................129
5.1 General....................................................................................................................129
5.2 Numerical Keypad ..................................................................................................129
5.3 Enter Key ...............................................................................................................129
5.4 Cancel Key .............................................................................................................129
5.5 !" #!" #
!" #!" #
!" # Keys ..........................................................................................................129
6.SETPOINTSKEYS&CHILLEDLIQUIDCONTROL ..........................................................................130
6.1 General....................................................................................................................130
6.2 Chilled Liquid Temperature Control .......................................................................130
6.3 Local Cooling Setpoints Key .................................................................................133
6.4 Remote Cooling Setpoints Key ..............................................................................133
7.CLOCKKEYS ...............................................................................................................................134
7.1 General....................................................................................................................134
7.2 Set Time Key ..........................................................................................................134
7.3 Set Schedule / Holiday Key ...................................................................................135
7.4 Manual Override Key .............................................................................................136
8.PROGRAMKEY ...............................................................................................................................137
8.1 General....................................................................................................................137
8.2 Program Key – User Programmable Values ............................................................137
8.3 Programming “Default” Values ..............................................................................141
8.4 4 Condenser Fan Control .......................................................................................142
SECTION 9MAINTENANCE .............................................................................................................146
GeneralRequirements ...........................................................................................................................146
Daily Maintenance...................................................................................................................................146
Scheduled Maintenance ..........................................................................................................................146
Chiller/Compressor Operating Log ..........................................................................................................146
CompressorUnitOperation ..................................................................................................................147
MaintenanceRequirements ...................................................................................................................148
General PeriodicMaintenance Checks– StandardUnits ....................................................................149
SECTION 10 SPAREPARTS...............................................................................................................150
Recommended Spares ..............................................................................................................................150
Recommended Compressor Oils ..............................................................................................................150
Associated Drawings ..............................................................................................................................150
SECTION 11 TROUBLESHOOTING ..................................................................................................151
CompetentPersonsTroubleshootingGuide..........................................................................................151
SensorCalibration Charts ....................................................................................................................153
LimitedWarrantyAppliedSystems ......................................................................................................154
TemperatureConversionChart.............................................................................................................155
TABLE OF CONTENTS (CONT’D)

6YORK INTERNATIONAL
INTRODUCTION
YORK YCAS Millennium chillers are manufactured
to the highest design and construction standards to en-
sure high performance, reliability and adaptability to
all types of air conditioning installations.
The unit is intended for cooling water or glycol solu-
tions and is not suitable for purposes other than those
specified in this manual.
This manual and the Microprocessor Operating Instruc-
tions contain all the information required for correct
installationand commissioning of the unit, togetherwith
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 in-
stallation, commissioning and maintenance tasks must
only be performed by suitably trained and qualified per-
sonnel.
The manufacturer will not be liable for any injury or
damage caused by incorrect installation, commission-
ing, operation or maintenance resulting from a failure
to follow the procedures and instructions detailed in
the manuals.
WARRANTY
York International warrants all equipment and materi-
als against defects in workmanship and materials for a
period of one year from initial start-up, or eighteen
months from delivery (whichever occurs first) unless
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 and run hours/starts. These de-
tails 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 must be carried out by
trained personnel from an Authorized YORK Ser-
vice Center. See Commissioning, page 39.
• Only genuine YORK approved spare parts, oils and
refrigerants must be used. Recommendations on
spare parts can be found on page 150.
• 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 146.
• Failure to satisfy any of these conditions will auto-
matically void the warranty. See Warranty Policy,
page 154.
SAFETY
Standards for Safety
YCASMillenniumchillersare designed and built within
an ISO 9002 accredited design and manufacturing or-
ganization. The chillers comply with the applicable sec-
tions of the following Standards and Codes:
• ANSI/ASHRAE Standard 15, Safety Code for Me-
chanical Refrigeration
• ANSI/NFPA Standard 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 Labo-
ratories (U.L.) for construction of chillers and provide
U.L./cU.L. listing label.
GENERAL CHILLER INFORMATION & SAFETY
General Chiller Information & Safety

7
YORK INTERNATIONAL
FORM201.18-NM6
RESPONSIBILITY FOR SAFETY
Every care has been taken in the design and manufac-
ture of the unit to ensure compliance with the safety
requirements listed above. However, the individual op-
erating or working on any machinery is primarily re-
sponsiblefor:
Personal safety, safety of other personnel, and the ma-
chinery.
Correct utilization of the machinery in accordance with
the procedures detailed in the manuals.
ABOUTTHIS 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 per-
sonal injury. Usually an instruction will be
given,togetherwithabriefexplanationand
the possible result of ignoring the instruc-
tion.
A Cautionidentifies a hazard which could
lead to damage to the machine, damage
to other equipment and/or environmental
pollution. Usually an instruction will be
given,together with a brief explanation and
the possible result of ignoring the instruc-
tion.
A Note is used to highlight additional infor-
mationwhichmaybehelpfultoyoubutwhere
there are no special safety implications.
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 reservesallrights.
They may not be reproduced, in whole or in part, with-
outprior written authorization from an authorizedYORK
representative.
MISUSE OF EQUIPMENT
Suitability for Application
Theunit is intended for cooling water orglycolsolutions
andisnotsuitableforpurposes other than those specified
inthese instructions. Any use of the equipment other than
its intended use, or operation of the equipment contrary
to the relevant procedures may result in injury to the op-
erator, 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 indi-
cated 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 fail-
ure 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 po-
tential hazards and precautions necessary for safe op-
eration and maintenance of equipment containing high
temperatures, pressures and voltages.
Pressure Systems
Theunit contains refrigerant vapor and liquid under pres-
sure, release of which can be a danger and cause injury.
The user should ensure that care is taken during installa-
tion, operation and maintenance to avoid damage to the
pressure system. No attempt should be made to gain ac-
cess to the component parts of the pressure system other
thanby suitably trained and qualified personnel.
Electrical
The unit must be grounded. No installation or mainte
nance work should be attempted on the electrical equip-
mentwith out first switching OFF,isolating and locking-
off the power supply. Work on live equipment must only
1

8YORK INTERNATIONAL
be carried out by suitably trained and qualified person-
nel. No attempt should be made to gain access to the
control panel or electrical enclosures during normal op-
eration of the unit.
Rotating Parts
Fan guards must be fitted at all times and not removed
unless the power supply has been isolated. If ductwork
is to be fitted, requiring the wire fan guards to be re-
moved, 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. For more comprehensive information on
safety precautions for use of refrigerants and oils, refer
to the Materials Safety Data tables provided on pages 9
through 11.
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-
surerelief device(s). Detergentsand solvents which may
cause corrosion should also be avoided.
EMERGENCYSHUTDOWN
In case of emergency the electrical option panel is fit-
tedwith an emergency stop switch CB3 (CircuitBreaker
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, it removes the
electrical supply from the control system, thus shutting
down the unit.
General Chiller Information & Safety

9
YORK INTERNATIONAL
FORM201.18-NM6
1
MATERIAL SAFETY DATA
SAFETYDATA R-22
Toxicity Low.
Liquid splashes or spray may cause freeze burns. Unlikely to be hazardous by skin absorption. R-22
In Contact With Skin may be slightly irritant and liquid has a degreasing effect. Thaw affected areas with water. Remove
contaminated clothing carefully - may adhere to skin in case of freeze burns. Wash affected areas
with plenty of warm water. If symptoms occur (irritation or blistering) obtain medical attention.
In Contact With Eyes Vapor has no effect. Liquid splashes or spray may cause freeze burns. Immediately irrigate with
eyewash solution or clean water for at least 10 minutes. Obtain immediate medical attention.
Highly unlikely to occur - but should this occur freeze burn will occur. Do not induce vomiting.
Ingested Provided patient is conscious, wash mouth with water and give about (0.5 pint) 250 ml to drink.
Obtain immediate medical attention.
High levels of vapor concentration initially produce stimulation and then depression of the central
nervous system causing headaches and giddiness and may lead to unconsciousness. Can prove
suddenly fatal if the exposure has been severe.
Inhalation At higher concentration there is a danger from asphyxiation due to reduced oxygen content of
atmosphere. Remove patient to fresh air, keep warm and at rest. Administer oxygen if necessary.
Apply artificial respiration if breathing has ceased or shows signs of failing. In event of cardiac arrest
apply external cardiac massage. Obtain immediate medical attention.
Further Symptomatic and supportive theory is indicated. Cardiac sensitization has been described which
Medical Advice may, in the presence of circulating catecholamines such as adrenaline, give rise to cardiac arrythmia
and subsequent arrest following exposure to high concentrations.
A lifetime inhalation study in rats and mice gives a small excess in salivary gland tumors in male
Long Term Exposure rats only at 50,000 ppm, 10,000 ppm showed no effect. This information suggests that R-22 does
not represent a carcinogenic hazard to humans.
Occupational Recommended limit: 1000 ppm v/v - 8 hr TWA 1250 ppm v/v - 12 hr TWA.
Exposure Limits
Stability Unstable.
Conditions to Avoid Use in presence of naked flames, red hot surfaces and high moisture levels.
Hazardous Reactions May react violently with sodium, potassium, barium and all other alkali and alkaline earth metals.
Incompatible materials: Magnesium and alloys containing more than 2% magnesium.
Hazardous
Decomposition Halogen acids formed by thermal decomposition.
Products Avoid inhalation of high concentrations of vapors. Atmospheric concentrations should be minimized
General Precautions and kept as low as reasonably practicable below the occupational exposure limit. The vapor is
heavier than air and collects at low level and in confined areas. Ventilate by extraction at lowest
levels.
Respiratory Protection Where doubt exists on atmospheric concentration, HSE approved breathing apparatus should be
worn. This should be self-contained or of the long breather type.
Storage Keep containers dry and in a cool place away from fire risk, direct sunlight, and all sources of heat
such as radiators. Keep at temperatures not exceeding 45°C (113°F).
Protective Clothing Wear overalls, impervious gloves and goggles/face protection.
Ensure suitable personal protective clothing and respiratory protection is worn. Provided it is safe to
do so, isolate the source of the leak. Allow small spillages to evaporate provided there is suitable
Spill / leak Procedure ventilation. Large spillages: Ventilate area. Contain spillages with sand, earth or any suitable
absorbent material. Prevent liquid from entering drains, sewers, basements and work pits since
vapor may create a suffocating atmosphere.
Disposal Best to recover and recycle. If this is not possible, destruction is to be in an approved facility which
is equipped to absorb and neutralize acids and other toxic processing products.
Fire Extinguishing Data Non-flammable.
Containers Fire exposed containers should be kept cool with water sprays. Containers may burst if overheated.
Fire Fighting Self contained breathing apparatus and protective clothing must be worn in fire conditions.
Protective Equip.
REFRIGERANT DATA:

10 YORK INTERNATIONAL
MATERIAL SAFETY DATA
Section 1 – PRODUCT NAME AND INFORMATION
Product (Trade Name and Synonyms): YORK “L” Oil
Chemical Name: Ester
Chemical Family: Polyol Ester
Formula: Proprietary
CAS#: Proprietary
Section 2 – COMPONENTS AND HAZARD STATEMENT
This product is non-hazardous. The product contains no known carcinogens. No special
warning labels are required under OSHA 29 CFR 1910.1200.
Section 3 – SAFE HANDLING AND STORAGE
Handling - Do not take internally. Avoid contact with skin, eyes, and clothing. Upon contact with skin, wash with
soap and water. Flush eyes with water for 15 minutes and consult physician. Wash contaminated
clothing before reuse.
Storage - Keep container tightly sealed when not in use. Product is hygroscopic. Storage under nitrogen
highly recommended.
Section 4 – PHYSICAL DATA
Appearance: Clear liquid, gray to yellow or light brown tint
Boiling Point: > 650°F
Vapor Pressure: <0.01 mmHg @ 20°C
Specific Gravity (water=1): 0.94-0.97
Volatiles, Percent by Volume: 0%
Odor: Mild, distinct
Solubility in Water: Negligible
Evaporation Rate (butyl acetate=1): Nil
Section 5 – FIRE AND EXPLOSION HAZARDS
Flash Point (by Cleveland Open Cup): 230-300°C
FlammableLimits: Not Established
Auto-IgnitionTemperature: nodata
HMIS Ratings:
Health: 0
Flammability: 1
Reactivity: 0
ExtinguishingMedia: Dry chemical; CO2 foam; water fog (see below)
Unusual Fire and Explosion Hazards: None
Special Fire Fighting Techniques: Burning fluid may evolve irritating/noxious fumes.
Firefighters should use NIOSH/MNSA-approved self-contained breath-
ing apparatus. Use water fog to cool fire-exposed containers. USE
WATER CAREFULLY NEAR EXPOSED/BURNING LIQUIDS. May
cause frothing and splashing of hot materials.
General Chiller Information & Safety

11
YORK INTERNATIONAL
FORM201.18-NM6
Section 6 – REACTIVITY DATA
Stability: Stable
HazardousPolymerization: Will not occur
Incompatible Materials: Strong oxidizers, caustic or acidic solutions
Conditions to Avoid: Excessive heat
Hazardous Decomposition Products: Analogous compounds evolve carbon monoxide, carbon dioxide,
and other unidentified fragments when burned. See Section 5.
This product may degrade some paints and rubber materials.
Section 7 – HEALTH HAZARD DATA
Threshold Limit Value: Not established
Situations to Avoid: Avoid breathing oil mists
First Aid Procedures:
Ingestion: Consult physician at once. May cause nausea and diarrhea.
Inhalation: Product is not toxic by inhalation. If oil mist is inhaled, remove to fresh air and consult
physician.
To the best of our knowledge, the toxicological properties of these compounds have not been fully investigated.
Analogous compounds are considered to be essentially non-toxic.
Section 8 – PERSONAL PROTECTION INFORMATION
RespiratoryProtection: Use in well ventilated area
Ventilation: Local exhaust
Protective Gloves: Strongly recommended, especially for prolonged exposure.
Eye/FaceProtection: Goggles
Firefighters should use NIOSH/MNSA-approved self-contained breathing apparatus. Use water fog to cool
fire-exposed containers. USE WATER CAREFULLY NEAR EXPOSED/BURNING LIQUIDS. May cause frothing
and splashing of hot material.
Section 9 – SPILL OR LEAK PROCEDURES
In Case of Spill: Wearsuitable protective equipment, especially goggles. Stopsource of spill. Dike spill area. Use
absorbent materials to soak up fluid (i.e. sand, sawdust, and commercially available materials).
Wash spill area with large amounts of water. Properly dispose of all materials.
Section 10 – WASTE DISPOSAL METHODS
Incinerate this product and all associated wastes in a licensed facility in accordance with Federal, State,
and local regulations.
The information in this material safety data sheet should be provided to all who use, handle, store, transport, or are
otherwiseexposed to this product. YORKbelieves theinformation in thisdocument tobe reliable andup todate as of
the date of publication, but makes no guarantee that it is.
1

12 YORK INTERNATIONAL
INTRODUCTION
YORK YCAS Millennium chillers are designed for
water or water-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 cooler to ensure that each refrigerant cir-
cuit operates correctly.
The unit structure is manufactured from heavy gauge,
galvanized steel. All external structural parts are coated
with“Desert Sand” baked-on enamel powder paint. This
providesa finish which, when subjected to ASTM B117,
500 hour, 5% salt spray conditions, shows breakdown
of less than 1/8" either side of a scribed line (equiva-
lent to ASTM D1654 rating of “6”).
All exposed power wiring is be routed through liquid-
tight, non-metallic conduit.
General Description
The Air Cooled Screw Chiller utilizes many compo-
nents which are the same or nearly the same as a stan-
dard 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 number of separate refrigerant circuits, a
single shell and tube DX evaporator, 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 by two helically grooved rotors
which are manufactured from forged steel. The 50 Hz
motor operates at 2975 RPM to direct drive the male
rotor which in turn drives the female rotor on a light film
ofoil.
PRODUCT DESCRIPTION
FIG. 1 – COMPONENT LOCATIONS
Product Description
1 System Fans
2 ControlPanel
3 PowerPanel
4 OptionPanel
5 Cooler
6 CondenserCoils
00400VIP
2
4
3
1
6
5
3

13
YORK INTERNATIONAL
FORM201.18-NM6
Refrigerant gas is injected into the void created by the
unmeshing of the five lobed male and seven lobed fe-
male rotor. Further meshing of the rotors closes the ro-
tor threads to the suction port and progressively com-
presses 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 dis-
charge end of the rotor casing. Since the intake and dis-
charge cycles overlap, a resulting smooth flow of gas is
maintained.
The rotors are housed in a cast iron compressor hous-
ing 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 they maintain accurate
rotor positioning at all pressure ratios, thereby mini-
mizing 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 over-
load 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 pres-
surized oil is then cooled in the condenser coils and
piped back to the compressor for lubrication. The com-
pressor design working pressure is 31 bar (450 PSIG).
Each chiller receives a 21 bar (300 PSIG) low side and
a 31 bar (450 PSIG) high side factory test. A 350 watt
(115-1-50) cartridge heater is located in the compres-
sor. The heater is temperature activated to prevent re-
frigerant condensation.
The following items are also included:
• Internaldischargecheckvalve to prevent rotor back-
spin or shutdown.
• An acoustically tuned, internal discharge muffler
to minimize noise, while operating flow for maxi-
mum performance.
• Discharge and suction shutoff valves.
• A rain-tight terminal box.
• A suction gas screen and serviceable, 0.5 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 refriger-
ant 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 cooler on the shell
side is 10 bar (150 PSIG), and 24 bar (350 PSIG) for
the tube (refrigerant side). The water baffles are fabri-
cated from galvanized steel to resist corrosion. Re-
movable heads are provided for access to internally en-
hanced, seamless, copper tubes. Water vent and drain
connections are included.
The cooler is equipped with a thermostatically con-
trolled heater for protection to -29°C (-20°F) ambient
andinsulated with19 mm (3/4")flexible closed-cellfoam.
The water nozzles are provided with grooves for me-
chanical couplings and should be insulated by the con-
tractor after pipe installation.
Condenser
The fin and tube condenser coils are manufactured from
seamless, internally enhanced, high condensing coeffi-
cient, corrosion resistant copper tubes arranged in stag-
FIG. 2 – SCREW COMPRESSOR LD03674
2

14 YORK INTERNATIONAL
gered rows and mechanically expanded into corrosion
resistant aluminum alloy fins with full height fin collars.
They have a design working pressure of 31 bar
(450 PSIG). Each coil is rested to 34 bar (495 PSIG).
Multiple fans move air through the coils. They are dy-
namically and statically balanced, direct drive with cor-
rosion resistant glass fiber reinforced composite blades
molded into low noise, full airfoil cross section, pro-
viding vertical air discharge from extended orifices for
efficiency and low sound. Each fan is located in a sepa-
rate compartment to prevent cross flow during fan cy-
cling. Guards of heavy gauge, PVC coated galvanized
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
(Models YCAS 0303, 0323 and 0343)
A plate and frame heat exchanger (economizer) is fit-
ted to both refrigerant circuits on models YCAS0303,
0323 and 0343. This increases the efficiency of the
system by subcooling the primary refrigerant liquid to
the evaporator.
The wet vapor to the economizer is supplied by a small
53kW TXV set for 5.5°C (10°F) superheat that flashes
off 10 - 20% of the liquid from the condenser. 35 - 42
kW are utilized for subcooling liquid refrigerant. The
wet vapor is at an intermediate pressure between dis-
charge and suction (1.7 x suction) and therefore little
energy is required to pump it back through the com-
pressor to condenser pressure. This results in a very
small loss to system efficiency.
The economizer provides approximately 14°C (25°F)
of additional subcooling to the liquid refrigerant which
flows to the evaporator at 35°C (95°F) ambient,13°C
(55°F) RWT, 7°C (44°F) LWT. Subcooling will drop to
approximately 0°C below 32°C (90°F) ambient. The
subcooled liquid is then fed to the primary TXV in the
system. This additional subcooling results in a signifi-
cant increase in the efficiency of the system. The de-
sign working pressure of the economizer is 31 bar (450
PSIG). The economizer liquid supply solenoid is acti-
vatedonstart-up coincident with the liquid line solenoid,
after pumpdown.
The economizer operation is controlled by the econo-
mizer solenoid valve. This valve is controlled by the
microprocessor. The valve will remain off for the first 3
minutes of compressor operation. After 3 minutes of
operation, the economizer solenoid valve will open if
the slide valve position is > Step 47, and the pressure
ratio (PR) of discharge pressure to suction pressure is
greater than 2.2 using the following formula:
English: PR = DP (PSIG) + 14.7
SP (PSIG) + 14.7
Metric: PR = DP (BAR) + 1
SP (BAR) + 1
The economizer valve will be turned off if the pressure
ratio drops below 2.0. It will also turn off if slide valve
position drops below Step 44. Under these conditions,
the valve is closed due to the lack of efficiency im-
provement available from the economizer.
Suction Line Heat Exchanger
(Optimized R-407C only)
A suction line heat exchanger is incorporated in the
optimized R-407C chiller to boost the performance of
the evaporator. This is accomplished by using the warm
liquid from the liquid line to heat the suction gas going
to the compressor. TXV bulb placement is between the
heat exchanger and the compressor to assure that 5.6°C
- 6.7°C (10 - 12°F) superheat is maintained.
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 dis-
charge gas is forced around a 90 degree bend. Oil is
forced to the outside of the separator through centrifu-
gal action and captured on wire mesh where it drains to
the bottom of the oil separator and into the compressor.
The oil (YORK “L” oil – a POE oil used for all refrig-
erant applications), which drains back into the com-
pressor through a replaceable 0.5 - 3.0 micron oil filter,
and oil supply solenoid, is at high pressure. This high
pressure “oil injection” forces the oil into the compres-
sor where it is gravity fed to the gears and bearings for
lubrication. After lubricating the gears and bearings, it
is injected through orifices on a closed thread near the
suction end of the rotors. The oil is automatically in-
jected because of the pressure difference between the
discharge pressure and the reduced pressure at the suc-
tion end of the rotors. This lubricates the rotors as well
as provides an oil seal against leakage around the rotors
Product Description

15
YORK INTERNATIONAL
FORM201.18-NM6
to assure refrigerant compression (volumetric effi-
ciency). 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 2.1 bar (30 PSID) exists between discharge and
1.2x suction, to force oil into rotor case, a minimum of
0.6 bar (10 PSID) is all that is required to assure pro-
tection of the compressor. Oil pressure safety is moni-
tored as the difference between suction and the pres-
sure of the oil entering the rotor case.
Maximum working pressure of the oil separator is 31
bar (450 PSIG). A relief valve is installed in the oil sepa-
rator piping. This will soon be incorporated into the oil
separator. 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 temperature control is provided through
liquidinjectionactivatedby the microprocessor,utilizing
a discharge temperature sensor, and a solenoid valve.
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 posi-
tion and provide a capacity control range from 10% -
100% of the full unit load using a continuous function
slide valve. The microprocessor modulates the current
signal to a 3-way pressure regulating capacity control
valve which controls command compressor capacity,
independent of system pressures, and balances the com-
pressor capacity with the cooling load. Loading is ac-
complished by varying pressure through the pressure
regulatingcapacity control valve to movethe slide valve
against the spring pressure to promote stable smooth
loading.
Automatic spring return of the slide valve to the mini-
mum 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 de-
signed 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
control section and an electrical options section. The
power and control sections have separate hinged,
latched, and gasket sealed doors equipped with wind
struts.
Each power compartment contains:
Compressor and fan starting contactors, fan motor ex-
ternal overloads, control circuit serving compressor ca-
pacity control, compressor and fan contactor coils and
compressor motor overloads.
Thecurrent transformers for the compressor motor over-
loads sense each phase, as an input to the microproces-
sor. This protects the compressor motors from damage
due to: low current input, high input current, unbal-
anced current, single phasing, phase reversal, and com-
pressor 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 115/1/50 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-
tionsforDisplay,Entry, Setpoints, Clock, Print, Pro-
gram and Unit ON/OFF.
The standard controls shall include: brine chilling, ther-
mal storage, automatic pump down, run signal contacts,
demand load limit from external building automation
system input, remote reset liquid temperature reset in-
put, unit alarm contacts, chilled liquid pump control,
automatic reset after power failure, automatic system
optimization to match operating conditions.
2

16 YORK INTERNATIONAL
Thesoftware is stored in non-volatile memory (EPROM)
to eliminate chiller failure due to AC power failure. The
ProgrammedSetpoint is stored in lithium batterybacked
memory.
Motor Current Protection
The microprocessor motor protection provides high cur-
rent 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 ac-
complished by sending 3-phase current signals propor-
tional to motor current from the Motor Protector mod-
ule to the Power Supply Board where the signals are
conditioned and routed 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 re-
spective system switch is required to clear the fault
and restart the system. A thorough check of the mo-
tor, wiring, and refrigerant system should be done be-
fore 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 protec-
tion 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
not tripped, and the mechanical high pressure cut-out
is not tripped. Once the system is locked out on Low
Motor Current, it must be manually reset with the sys-
tem 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 MP and 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.
Motor Protection Module
The mechanical motor protector is a Texas Instruments
2ACE Three Phase Protection Module (Fig. 36, page
102)thermalandcurrent motor overload protection. This
module protects against phase to phase current imbal-
ance, over current, under current, and phase rotation.
The module, mounted in the power panel, 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 alphanumeric
value which can be decoded by the operator. A list of
the codes follows:
HAXXX Normal motor OFF display. Sequentially
sweeps through the motor protection dip
switch setting.
0Normal - no fault detected (Running)
Flashing “0” Motor off or unloaded < 5A (Running)
AC current level.
1High current fault.
2Loaded phase to phase current
imbalance > 17%.
3Unloaded phase to phase current
imbalance > 25%.
4Improper incoming phase rotation.
5High motor temperature. Trip point =
13kW, reset = 3.25kW.
6Communication error.
7Unload imbalance ( > 50%)
8Phase Loss (> 60%)
EOut of range of RLA calibration.
Other symbols Defective module or supply voltage.
Working voltage 18 - 30 VAC, 224 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 allowing the mo-
tor 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 re-
set device. After the first start the modules’ contacts
will be open preventing the motor contactors from en-
ergizing. Power must be removed and reapplied to re-
set the module.
Product Description

17
YORK INTERNATIONAL
FORM201.18-NM6
Current Overload
The2ACE module design uses one integral current trans-
former 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 cur-
rent overload trip value. See Table 1 (pages 18 and 19).
For the location of the dip switches and determining the
ON position refer to the “Note” below and Figure 40.
For the location of the dip switches and determining the
ON side of the switches, refer to Figure 40, page 108.
As indicated, to place a switch in the ON position re-
quires pushing the switch to the left.
A switch must be pushed to the left to
place the switch in the ON position.
It is recommended that an YORK Ser-
vice Technician or the YORK factory
be consulted before changing these
settings for any reason, since damage
to the compressor could result.
Changesshouldneverbe made unless
it is verified that the settings are in-
correct.
Anytime a dip switch change is made,
power must be cycled off and on to the
moduleto reprogramthemodule tothe
new valve.
Thermal Overload
Three PTC (positive temperature coefficient) ther-
mistors in the motor windings of each phase provides
thermal protection. The sensor resistance stays rela-
tively constant at 1kΩuntil a temperature of 130°C
(266°F) is sensed. The sensor experiences a rapid rise
in resistance beyond this temperature. Whenever the
resistance of one of the sensors reaches 13kΩ, 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.
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 “Operat-
ing Current” to the measured half line current. The “Op-
erating Current” is given by 0.65 X factory overload
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 cir-
cuit 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 deter-
mine 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 re-
sponse time.
2

18 YORK INTERNATIONAL
Product Description
TABLE 1 – MOTOR PROTECTOR DIP SWITCH SETTING
YCAS STYLE F, ACROSS-THE-LINE START – 50 HZ
MODEL VOLT CHILLER 100% NO. MOTOR PROTECTOR
NO. CODE NAMEPLATE FLA LEADS MP OL
RLA OF PER VALUE
SYS. PHASE SET DIP SWITCH SETTINGS ON MP (“1” INDICATED ON)
128 64 32 16 8 4 2 1
0283 50 68 73 2 92 0 1 0 1 1 1 0 0
0303 50 70 76 2 94 0 1 0 1 1 1 1 0
0323 50 96 104 2 130 1 0 0 0 0 0 1 0
0343 50 102 110 2 138 1 0 0 0 1 0 1 0

19
YORK INTERNATIONAL
FORM201.18-NM6
2
TABLE 1 – MOTOR PROTECTOR DIP SWITCH SETTING (CONT’D)
YCAS STYLE F, WYE-DELTA START – 50 HZ
MODEL VOLT CHILLER 100% NO. MOTOR PROTECTOR
NO. CODE NAMEPLATE FLA LEADS MP OL
RLA OF PER VALUE
SYS. PHASE SET DIP SWITCH SETTINGS ON MP (“1” INDICATED ON)
128 64 32 16 8 4 2 1
0283 50 68 73 2 92 0 1 0 1 1 1 0 0
0303 50 70 76 2 94 0 1 0 1 1 1 1 0
0323 50 96 104 2 130 1 0 0 0 0 0 1 0
0343 50 102 110 2 138 1 0 0 0 1 0 1 0

20 YORK INTERNATIONAL
MOTOR STARTING
Two types of compressor motor starting are available:
Across-the-Line and optional Wye-Delta Open Transi-
tion Starter.
Across-the-Line starters will utilize one contactor and
one start relay per compressor. The optional Wye-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% LRA for the first 4 to 10 sec-
onds, with current increasing to normal running cur-
rent 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 transi-
tion of the 1CR (SYS 1) or 2CR (SYS 2) relay contacts
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 (SYS 1) or
4M (SYS 2) motor contactors from energizing. Auxil-
iary 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 10 seconds depending upon motor current as
sensed by the microprocessor. Normally, the transition
to Delta takes 10 seconds if current is below 125% FLA.
If motor current exceeds 125% 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 10 sec-
onds, the 1TR (SYS 1) or 2TR (SYS 2) transition delay
relay is enabled by the microprocessor from Relay Out-
put 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)remainenergizesthrough
interlockingcontacts 1M (SYS 1) or 3M(SYS 2). Open-
ing of the 1TR (SYS 1) or 2TR (SYS 2) contacts de-
energizes1S/2S and closes thenormally closed 1S (SYS
1) or 2S (SYS 2) contacts, energizing motor contactor
2M (SYS 1) or 4M (SYS 2), completing the “DELTA”
connection of the motor.
1 TR and 2TR are NOT “timing” re-
lays. These devices are simply pilot
relays identical to 1CR and 2CR.
KEYPADCONTROLS
Display
Parameters are displayed in Metric (°C and Bars) or
English (°F and PSIG) 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 operating hours and starts. 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 full load compressor motor current per
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 leav-
ing liquid temperature.
• Unloading limit setpoints for high discharge pres-
sure and compressor motor current.
• Liquid pull-down rate sensitivity (0.3°C to 2.8°C
[0.5°F to 5°F] /minute in 0.1° increments).
• 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.
Product Description