York MILLENNIUM YCAS Owner's manual

INSTALLATION, OPERATION, MAINTENANCE
MILLENNIUM
TM
AIR-COOLED SCREW LIQUID CHILLERS
Supersedes:Nothing Form201.18-NM2(1199)
MILLENNIUM
TM
YCAS AIR-COOLED SCREW LIQUID CHILLER
YCAS0373–YCAS0653
YCAS 2-SYSTEM With EPROM (Standard, Brine & Metric Models Combined)031-01798-001
YCAS 3-SYSTEM EPROM +I/O Board EPROM
031-02018-001031-01798-002
YCAS 4-SYSTEM EPROM +I/O Board EPROM
031-02018-001031-01798-002
Microprocessor Board
Microprocessor Board
28971AR

2YORKINTERNATIONAL
TABLE OF CONTENTS
General Safety Guidelines...................................................................................................................... 6
Safety Symbols........................................................................................................................................ 6
Changeability of this Document ............................................................................................................. 7
Nomenclature ......................................................................................................................................... 7
SECTION 1GENERALCHILLERINFORMATION&SAFETY
Introduction ......................................................................................................................................... 8
Warranty ......................................................................................................................................... 8
Safety ......................................................................................................................................... 8
Responsibility for Safety ......................................................................................................................... 8
About this Manual.................................................................................................................................... 8
Misuse of Equipment .............................................................................................................................. 8
Emergency Shutdown........................................................................................................................... 10
Material Safety Data ...............................................................................................................................11
SECTION 2PRODUCTDESCRIPTION
Introduction ....................................................................................................................................... 14
General Description.............................................................................................................................. 14
Motor Starting ....................................................................................................................................... 24
Keypad Controls.................................................................................................................................... 24
Accessories and Options ..................................................................................................................... 25
DX Cooler Options ................................................................................................................................ 26
Unit Enclosures..................................................................................................................................... 26
Fans ....................................................................................................................................... 26
Sound Reduction Options .................................................................................................................... 26
Vibration Isolation ................................................................................................................................. 26
Unit Nomenclature – Nameplate Engineering Data ........................................................................... 27
SECTION 3HANDLINGANDSTORAGE
Delivery and Storage............................................................................................................................. 28
Inspection ....................................................................................................................................... 28
Moving the Chiller.................................................................................................................................. 28
SECTION 4INSTALLATION
Location Requirements ........................................................................................................................ 29
Outdoor Installations ............................................................................................................................ 29
Indoor Installations ............................................................................................................................... 29
Location Clearances ............................................................................................................................ 29
Installation of Vibration Isolators .......................................................................................................... 30
Shipping Braces.................................................................................................................................... 30
Pipework Connection............................................................................................................................ 30
Water Treatment.................................................................................................................................... 31
Pipework Arrangement ......................................................................................................................... 31
Connection Types & Sizes .................................................................................................................... 32
Cooler Connections.............................................................................................................................. 32
Refrigerant Relief Valve Piping ............................................................................................................. 32
Ductwork Connection............................................................................................................................ 32
Electrical Connection ............................................................................................................................ 33
Power Wiring ....................................................................................................................................... 33
Power and Control Panel Layouts ....................................................................................................... 35
SECTION 5COMMISSIONING
Preparation ....................................................................................................................................... 37
Preparation - Power Off......................................................................................................................... 37
First Time Start-up ................................................................................................................................ 39
SECTION 6OPERATION
General Description.............................................................................................................................. 40
Start-up ....................................................................................................................................... 40
Normal Running and Cycling ............................................................................................................... 40
Shutdown ....................................................................................................................................... 40

3
YORKINTERNATIONAL
FORM201.18-NM2
TABLE OF CONTENTS
SECTION 7TECHNICALDATA
Temperatures and Flows...................................................................................................................... 41
Water Pressure Drop ............................................................................................................................ 41
Glycol Correction Factors...................................................................................................................... 42
Physical Data ....................................................................................................................................... 43
Operating Limitations ...................................................................................................................... 43
Sound Power Data ........................................................................................................................... 43
R-22 Refrigerant ............................................................................................................................... 44
R-407C Refrigerant.......................................................................................................................... 45
Electrical Data ....................................................................................................................................... 46
Multiple Point Power Supply Connection ........................................................................................ 46
Optional Single Point Power Supply Connection with Internal Unit Circuit Breakers................... 48
Optional Single Point Power Supply Connection to Factory Circuit Breaker ................................. 48
Control Power Supply ...................................................................................................................... 48
Compressor Data ............................................................................................................................ 48
Fan Data ....................................................................................................................................... 48
Electrical Notes & Legend ............................................................................................................... 49
Power Connection Options................................................................................................................... 50
Multiple Point Power Supply Connection ........................................................................................ 50
Optional Single Point Power Supply Connection with Internal Unit Circuit Breakers................... 50
Optional Single Point Power Supply Connection to Factory Circuit Breaker ................................. 51
Wiring Diagrams ................................................................................................................................... 52
Dimensions ....................................................................................................................................... 70
YCAS0373 - YCAS0503 ................................................................................................................... 70
YCAS0543 - YCAS0623 ................................................................................................................... 72
YCAS0653 ....................................................................................................................................... 74
Operating Weights - Aluminum Fin Coils ............................................................................................ 76
Isolator Selection - Aluminum Fin Coils .............................................................................................. 77
Operating Weights - Copper Fin Coils................................................................................................. 78
Isolator Selection - Copper Fin Coils ................................................................................................... 79
Refrigerant Flow Diagram .................................................................................................................... 84
Process and Instrumentation Diagram ............................................................................................... 85
Component Locations .......................................................................................................................... 86
Compressor Components ................................................................................................................... 87
SECTION 8START-UP
System Startup Checklist...................................................................................................................... 93
SECTION 9MICROPANEL
Chiller Control Panel Programming & Data Access ...................................................................... 97
Display and Status Information Keys .............................................................................................. 97
Program & Setup Keys..................................................................................................................... 97
1. INTRODUCTION & PHYSICAL DESCRIPTION ............................................................................... 98
1.1 General ................................................................................................................................... 98
1.2 Keypad & Display.................................................................................................................... 98
1.3 Unit (Chiller) ON / OFF Switch................................................................................................ 98
1.4 Microprocessor Board ............................................................................................................ 98
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 ..................................................................................................... 100
1.10 EMS/BAS Connections ......................................................................................................... 102
1.11 Microprocessor Board Layout .............................................................................................. 104
1.12 Logic Section Layout ............................................................................................................ 105
1.13 Anti-Recycle Timer................................................................................................................ 106
1.14 Anti-Coincidence Timer........................................................................................................ 106
1.15 Evaporator Pump Control ..................................................................................................... 106
1.16 Compressor Heater Control ................................................................................................ 106

4YORKINTERNATIONAL
1.17 Evaporator Heater Control.................................................................................................... 106
1.18 Pumpdown (LLSV) Control .................................................................................................. 106
1.19 Alarms ................................................................................................................................... 106
1.20 Run Status (Chiller).............................................................................................................. 107
1.21 Lead / Lag Compressor Selection ...................................................................................... 107
1.22 3/4 Compressor Chiller Configuration ................................................................................ 107
2.STATUSKEY&FAULTMESSAGES ................................................................................................ 108
2.1 General ................................................................................................................................. 108
2.2 General Status Messages ................................................................................................... 108
2.3 Unit Warnings ....................................................................................................................... 109
2.4 Anticipation Control Status Messages .................................................................................110
2.5 Unit Fault Status Messages ..................................................................................................111
2.6 System Fault (Safety) Status Messages ...............................................................................112
2.7 Printout on Fault Shutdown ...................................................................................................115
3. DISPLAY KEYS & OPTION SWITCHES ...........................................................................................116
3.1 General ..................................................................................................................................116
3.2 Chilled Liquid Temperatures Key ........................................................................................116
3.3 System Data Keys..................................................................................................................116
3.4 Ambient Temp Key .................................................................................................................117
3.5 Motor Current Key ..................................................................................................................117
3.6 Operating Hours / Start Counter Key ....................................................................................118
3.7 Options Key & Dip Switch Settings .......................................................................................118
3.8 Function Key...........................................................................................................................119
4. PRINT KEYS .................................................................................................................................... 120
4.1 General ................................................................................................................................. 120
4.2 Oper Data Key ....................................................................................................................... 120
4.3 Operating Data - Local Display Messages ......................................................................... 120
4.4 Operating Data - Remote Printout ....................................................................................... 122
4.5 History Key ............................................................................................................................ 123
4.6 Fault History Data - Local Display Messages ..................................................................... 123
4.7 Fault History Data - Remote Printout ................................................................................... 126
5. ENTRYKEYS ................................................................................................................................... 127
5.1 General ................................................................................................................................. 127
5.2 Numerical Keypad ................................................................................................................ 127
5.3 Enter Key ............................................................................................................................... 127
5.4 Cancel Key ............................................................................................................................ 127
5.5 - ¯ Keys................................................................................................................................. 127
6. SETPOINTS KEYS .......................................................................................................................... 128
6.1 General ................................................................................................................................. 128
6.2 Chilled Liquid Temperature Control .................................................................................... 128
6.3 Local Cooling Setpoints Key ................................................................................................ 131
6.4 Remote Cooling Setpoints Key............................................................................................ 131
7. CLOCK KEYS .................................................................................................................................. 132
7.1 General ................................................................................................................................. 132
7.2 Set Time Key ......................................................................................................................... 132
7.3 Set Schedule / Holiday Key .................................................................................................. 132
7.4 Manual Override Key............................................................................................................. 134
8.PROGRAMKEY ............................................................................................................................... 135
8.1 General ................................................................................................................................. 135
8.2 Program Key - User Programmable Values ....................................................................... 136
8.3 Programming "Default" Values ............................................................................................ 139
8.4 Condenser Fan Control........................................................................................................ 141
SECTION 10 MAINTENANCE
General Requirements .................................................................................................................. 142
Daily Maintenance .......................................................................................................................... 142
Scheduled Maintenance ................................................................................................................ 142
Chiller/Compressor Operating Log............................................................................................... 143
Maintenance Requirements .......................................................................................................... 144

5
YORKINTERNATIONAL
FORM201.18-NM2
LIST OF FIGURES
General Periodic Maintenance Checks - Standard Units ............................................................ 145
SPARE PARTS ..................................................................................................................................... 146
Recommended Spares ................................................................................................................. 146
Recommended Compressor Oils................................................................................................. 146
Associated Drawings..................................................................................................................... 146
TROUBLESHOOTING ......................................................................................................................... 147
Competent Person’s Troubleshooting Guide .............................................................................. 147
Sensor Calibration Charts ............................................................................................................. 149
Limited Warranty............................................................................................................................. 150
Temperature Conversion Chart ..................................................................................................... 151
FIG.1 - Component Locations .............................. 14
FIG.2 - Screw Compressor ................................... 15
FIG.3 - Unit Rigging............................................... 28
FIG.4 - Lifting Lugs ................................................ 28
FIG.5 - Pipework Arrangement.............................. 29
FIG.6 - Victaulic Groove ......................................... 32
FIG.7 - Flange Attachments .................................. 32
FIG.8 - Panel Layouts............................................ 35
FIG.9 - Customer Connections............................. 36
FIG.10 - Flow Rate and Pressure Drop Charts ...... 41
FIG.11 - Glycol Correction Factors .......................... 42
FIG.12 - Elementary Diagram:
Across-The-Line Start ............................... 52
FIG.13 - Power Panel (Front Inside View)
Across-The-Line Start ............................... 56
FIG.14 - Electronic Panel (Front Inside View)
Across-The Line Start................................ 57
FIG.15 - Elementary Diagram: Wye-Delta Start ...... 58
FIG.16 - Power Panel (Front Inside View)
Wye-Delta Start .......................................... 62
FIG.17 - Electronic Panel (Front Inside View)
Wye-Delta Start .......................................... 63
FIG.18 - Connection Diagram ................................. 64
FIG.19 - Detail “A” .................................................... 65
FIG.20 - Connection Diagram System Wiring ........ 66
FIG.21 - Sensor Connection ................................... 66
FIG.22 - Compressor (Systems 1 & 2) ................... 66
FIG.23 - Compressor Terminal Boxes.................... 67
FIG.24 - Detail “B”.................................................... 68
FIG.25 - Detail “C” ................................................... 69
FIG.26 - Isolator Details .......................................... 80
FIG.27 - Isolator Details .......................................... 81
FIG.28 - Isolator Locations...................................... 82
FIG.29 - Clearances ................................................ 83
FIG.30 - Refrigerant Flow Diagram ......................... 84
FIG.31 - Process & Instrumentation Diagram ........ 85
FIG.32 - Component Locations .............................. 86
FIG.33 - Component Locations .............................. 87
FIG.34 - Component Locations .............................. 88
FIG.35 - Component Locations .............................. 89
FIG.36 - Component Locations .............................. 90
FIG.37 - Component Locations .............................. 91
FIG.38 - Component Locations .............................. 92
FIG. 39 - Motor Protector ........................................ 101
FIG. 40 - Component Layout .................................. 104
FIG.41 - Logic Section Layout ............................... 105
FIG.42 - Suction Pressure Cutout ......................... 114
FIG.43 - Enlarged Photograph of Dip Switches
on Microprocessor Board........................ 119
FIG.44 - Condenser Fan Layout for DXST
2-Compressor Units ............................... 141
FIG.45 - Operating Log.......................................... 143
LIST OF TABLES
TABLE 1 - Motor Protector Dip Switch Settings...................................................................................... 20
TABLE 2 - Condenser Fan Control and Fan Contactor Data for DXST Units with 4 Fans System .... 141
TABLE 3 - Condenser Fan Control and Fan Contactor Data for DXST Units with 5 Fans System .... 141

6YORKINTERNATIONAL
This equipment is a relatively complicated apparatus.
During installation, operation, maintenance or service,
individuals may be exposed to certain components or
conditionsincluding, but not limited to: refrigerants,oils,
materials under pressure, rotating components, and both
high and low voltage. Each of these items has the po-
tential,if misused or handled improperly, to cause bodily
injury or death. It is the obligation and responsibility 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 dam-
age to the equipment and the property in which it is
IMPORTANT!
READ BEFORE PROCEEDING!
GENERAL SAFETY GUIDELINES
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 indi-
vidual possesses independent training that will enable
themto perform their assigned tasks properly and safely.
It is essential that, prior to performing any task on this
equipment,this individualshallhave read andunderstood
this document and any referenced materials. This indi-
vidual shall also be familiar with and comply with all
applicable governmental standards and regulations per-
taining to the task in question.
SAFETY SYMBOLS
Thefollowingsymbolsare usedinthisdocument toalertthereader toareasofpotential hazard:
CAUTION identifies a hazard which
could lead to damage to the machine,
damagetoother equipment and/or en-
vironmental pollution. Usually an in-
struction 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, will result in death or seri-
ous injury.
WARNING indicates a potentially
hazardous situation which, if not
avoided, could result in death or seri-
ous injury.
External wiring, unless specified as an optional connection in the manufacturer’s product
line,isNOT to be connected inside themicropanelcabinet.Devicessuch as relays, switches,
transducers and controls may NOT be installed inside the micro panel. NO external wiring
isallowedtoberunthrough the micro panel. All wiring must be in accordance with YORK’s
publishedspecifications and must be performed ONLY by qualified YORKpersonnel.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.

7
YORKINTERNATIONAL
FORM201.18-NM2
CHANGEABILITY OF THIS DOCUMENT
In complying with YORK’s policy for continuous prod-
uct 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 con-
tacting the nearest YORK Applied Systems Service
office.
It is the responsibility of operating/service personnel
as to 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 equip-
ment, they should verify with the owner whether the
equipment has been modified and if current literature
is available.
NOMENCLATURE
YC A S 0373 S B 50 Y F
TheModel Numberdenotes thefollowing characteristicsof theunit:
YORKChiller
YC = YORKChiller
Air-Cooled
CompressorType
S = Screw
NominalCapacity (kw)
UnitDesignator
S = Standard Unit
E = High Efficiency
H = High Static Fans
DesignSeries
TypeStart
Y = Star (WYE)-Delta
X = Across-the-Line
VoltageCode
50=380/415-3-50
Refrigerant
B = R-407C
C = R-22

8YORKINTERNATIONAL
INTRODUCTION
YORK Millennium YCAS 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 in-
stallation 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 in-
stallation, 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 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 warrants all equipment and materials 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 war-
ranty 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 design parameters.
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.
Theunit warranty will be void if any modification to the
unit is carried out without prior written approval from
YORK.
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 37.
• OnlygenuineYORK-approvedspareparts,oilsand
refrigerants must be used. Recommendations on
spare parts can be found on page 146.
• 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 142.
Failure to satisfy any of these conditions will automati-
cally void the warranty. See Warranty Policy, page 150.
SAFETY
Standards for Safety
MillenniumYCAS chillers are 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, Centrifugal and Rotary
Screw Water Chilling Packages
In addition, the chillers conform to Underwriters Labo-
ratories (U.L.) for construction of chillers and provide
UL/cUL listing label.
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
machinery.
GENERAL CHILLER INFORMATION & SAFETY
General Chiller Information & Safety

9
YORKINTERNATIONAL
FORM201.18-NM2
• 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 docu-
ment to identify a hazard which could
lead to personal injury. Usually an in-
struction will be given, together with
a brief explanation and the possible re-
sult of ignoring the instruction.
A CAUTION identifies a hazard which
could lead to damage to the machine,
damage to other equipment and/or en-
vironmental pollution. Usually an in-
struction will 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 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,aretheproperty of YORK which reserves all rights.
They may not be reproduced, in whole or in part, with-
outprior written authorizationfrom an authorized YORK
representative.
MISUSE OF EQUIPMENT
Suitability for Application
Theunitisintended for cooling water or glycol solutions
and is not suitable for purposes other than those speci-
fiedin these instructions. Any use of the equipment other
than its intended use, or operation of the equipment con-
trary 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 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 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
operationand maintenance of equipment containinghigh
temperatures, pressures and voltages.
Pressure Systems
Theunit contains refrigerant vapor andliquidunder pres-
sure, release of which can be a danger and cause in-
jury. The user should ensure that care is taken during
installation, operation and maintenance to avoid dam-
age to the pressure system. No attempt should be made
to gain access to the component parts of the pressure
system other than by suitably trained and qualified
personnel.
Electrical
The unit must be grounded. No installation or mainte-
nance work should be attempted on the electrical equip-
ment without first switching OFF, isolating and locking-
off the power supply. Work on live equipment must only
be carried out by suitably trained and qualified person-
nel. No attempt should be made to gain access inside
the control panel or electrical enclosures during normal
operation of the unit.
1

10 YORKINTERNATIONAL
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 fins on the air-cooled condenser coils have 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
11 through 13.
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-
surereliefdevice(s). Detergents and solvents which may
cause corrosion should also be avoided.
EMERGENCYSHUTDOWN
In case of emergency, the electrical option panel is fit-
ted with anemergency stop switch CB3 (CircuitBreaker
3), located in the bottom right of the Microprocessor
Panel. Separate Circuit Breakers, CB1 (System 1) and
CB2 (System 2) can also be used to stop the respective
system in an emergency. When operated, each removes
the electrical supply from the control system, thus shut-
ting down the unit.
General Chiller Information & Safety