York YCAS0098EB Owner's manual

YCAS AIR-COOLED LIQUID CHILLERS
YCAS0098EB through YCAS0208EB
YCAS 2 SYSTEM EPROM 031-01798-001 (STANDARD, BRINE & METRIC MODELS COMBINED)
28971AR
60 Hz
AIR-COOLED SCREW LIQUID CHILLERS
INSTALLATION, OPERATION, MAINTENANCE Supersedes: 201.18-NM7 (916) Form 201.18-NM7 (1020)
Issue Date:
October 2, 2020

2JOHNSON CONTROLS
This equipment is a relatively complicated apparatus.
During rigging, installation, operation, maintenance,
or service, individuals may be exposed to certain com-
ponents or conditions including, but not limited to:
heavy objects, refrigerants, materials under pressure,
rotating components, and both high and low voltage.
Each of these items has the potential, if misused or
handled improperly, to cause bodily injury or death. It
is the obligation and responsibility of rigging, instal-
lation, and operating/service personnel to identify and
recognize these inherent hazards, protect themselves,
and proceed safely in completing their tasks. Failure
to comply with any of these requirements could result
in serious damage to the equipment and the property in
IMPORTANT!
READ BEFORE PROCEEDING!
GENERAL SAFETY GUIDELINES
which it is situated, as well as severe personal injury or
death to themselves and people at the site.
This document is intended for use by owner-authorized
rigging, installation, and operating/service personnel. It
is expected that these individuals possess independent
training that will enable them to perform their assigned
tasks properly and safely. It is essential that, prior to
performing any task on this equipment, this individual
shall have read and understood the on-product labels,
this document and any referenced materials. This in-
dividual shall also be familiar with and comply with
all applicable industry and governmental standards and
regulations pertaining to the task in question.
SAFETY SYMBOLS
The following symbols are used in this document to alert the reader to specific situations:
Indicates a possible hazardous situation
which will result in death or serious injury
if proper care is not taken.
Indicates a potentially hazardous situa‑
tion which will result in possible injuries
or damage to equipment if proper care is
not taken.
Identifies a hazard which could lead
to damage to the machine, damage to
other equipment and/or environmental
pollution if proper care is not taken or
instructions and are not followed.
Highlights additional information useful
to the technician in completing the work
being performed properly.
External wiring, unless specied as an optional connection in the manufacturer’s product line, is not
to be connected inside the control cabinet. Devices such as relays, switches, transducers and controls
and any external wiring must not be installed inside the micro panel. All wiring must be in accor‑
dance with Johnson Controls’ published specications and must be performed only by a qualied
electrician. Johnson Controls will NOT be responsible for damage/problems resulting from improper
connections to the controls or application of improper control signals. Failure to follow this warning
will void the manufacturer’s warranty and cause serious damage to property or personal injury.

3
JOHNSON CONTROLS
FORM 201.18-NM7
CHANGEABILITY OF THIS DOCUMENT
In complying with Johnson Controls’ policy for contin-
uous product improvement, the information contained
in this document is subject to change without notice.
Johnson Controls makes no commitment to update
or provide current information automatically to the
manual or product owner. Updated manuals, if appli-
cable, can be obtained by contacting the nearest John-
son Controls Service office or accessing the Johnson
Controls Knowledge Exchange website at https://docs.
johnsoncontrols.com/chillers/.
It is the responsibility of rigging, lifting, and operating/
service personnel to verify the applicability of these
documents to the equipment. If there is any question
regarding the applicability of these documents, rig-
ging, lifting, and operating/service personnel should
verify whether the equipment has been modified and
if current literature is available from the owner of the
equipment prior to performing any work on the chiller.
REVISION NOTES
Revisions made to this document are indicated in the following table. These revisions are to technical information,
and any other changes in spelling, grammar, or formatting are not included.
AFFECTED PAGES DESCRIPTION
3 Conditioned Based Maintenance program information added
CONDITIONED BASED MAINTENANCE
Traditional chiller maintenance is based upon assumed
and generalized conditions. In lieu of the tradition-
al maintenance program, a Johnson Controls YORK
Conditioned Based Maintenance (CBM) program can
be substituted. This CBM service plan is built around
the specific needs for the chiller, operating conditions,
and annualized impact realized by the chiller. Your lo-
cal Johnson Controls Branch can propose a customized
Planned Service Agreement that leverages real time
and historical data, delivering performance reporting,
corrective actions required and data enabled guidance
for optimal operation and lifecycle assurance. The pro-
gram will include fault detection diagnostics, operation
code statistics, performance based algorithms and ad-
vance rules based rationale delivered by the Johnson
Controls Connected Equipment Portal.

4JOHNSON CONTROLS
SECTION 1GENERAL CHILLER
INFORMATION & SAFETY
Introduction ..............................................................7
Warranty.................................................................... 7
Safety ..........................................................................7
Standards for Safety ................................................7
Responsibility for Safety...........................................8
About this Manual.....................................................8
Misuse of Equipment ................................................8
Suitability for Application .......................................8
Structural Support....................................................8
Mechanical Strength................................................ 8
General Access ........................................................ 8
Pressure Systems .....................................................8
Electrical.................................................................. 8
Rotating Parts ..........................................................9
Sharp Edges .............................................................9
Refrigerants and Oils............................................... 9
High Temperature and Pressure Cleaning ...............9
Emergency Shutdown ...............................................9
Material Safety Data...............................................10
SECTION 2PRODUCT DESCRIPTION
Introduction .............................................................14
General Description ..............................................14
Compressor ...........................................................14
Evaporator ............................................................15
Condenser ..............................................................15
Oil Separator / System ..........................................16
Oil Cooling ...........................................................16
Capacity Control ................................................... 16
Power and Control Panel ......................................16
Microprocessor Controls .......................................17
Motor Current Protection ......................................17
Motor Protection Module ......................................18
Current Overload ...................................................18
Thermal Overload..................................................19
Current Imbalance .................................................19
Improper Phase Sequence...................................... 19
Motor Protector Dip Switch Settings ....................20
Motor Starting......................................................... 22
Keypad Controls......................................................22
Display...................................................................22
Entry ......................................................................23
Setpoints ................................................................23
Clock......................................................................23
Print .......................................................................23
Program .................................................................23
Accessories and Options ........................................ 23
Multiple Point Power Connection (Standard) ....... 23
Single-Point Power Connection
with Individual Circuit Protection .........................23
Single-Point Power Connection
with Combined Circuit Protection.........................23
Single-Point Power Connection
without Circuit Protection ..................................... 23
Control Circuit Terminal Block.............................23
Building Automation System (BAS) Interface...... 23
Condenser Coil Protection .................................... 23
DX Cooler Options ..................................................24
300 PSIG (21 bar) Waterside Design Working
Pressure..................................................................24
1-1/2” (38 mm) Insulation .....................................24
Flange Accessory................................................... 24
Remote DX Cooler ................................................24
Flow Switch Accessory ........................................24
Star-Delta Compressor Motor Starter....................24
Unit Enclosures........................................................24
Fans...........................................................................24
Sound Reduction Options.......................................24
Vibration Isolation ................................................. 24
Unit Nomenclature & Nameplate
Engineering Data..................................................... 25
Basic Part Number.................................................25
Options Section of Part Number............................26
SECTION 3HANDLING AND STORAGE
Delivery and Storage ..............................................27
Inspection ................................................................27
Moving the Chiller ................................................. 27
Lifting Weights ..................................................... 27
Unit Rigging ............................................................28
SECTION 4INSTALLATION
Location Requirements .......................................... 29
Outdoor Installations ..............................................29
Indoor Installations................................................. 29
Location Clearances................................................29
Installation of Vibration Isolators..........................30
Installation .............................................................30
Shipping Braces....................................................... 30
Pipework Connection..............................................30
General Requirements ........................................... 30
Water Treatment .....................................................31
Pipework Arrangement .......................................... 32
Connection Types & Sizes.......................................32
Cooler Connections .................................................32
Option Flanges.......................................................32
Refrigerant Relief Valve Piping ............................32
Ductwork Connection ............................................32
TABLE OF CONTENTS

5
JOHNSON CONTROLS
FORM 201.18-NM7
TABLE OF CONTENTS (CONT’D)
General Requirements ........................................... 32
Electrical Connection..............................................33
Power Wiring...........................................................33
Standard Units with Multi Point Power Supply
Wiring.......................................................................33
Units with Single-Point Power Supply Wiring......33
115VAC Control Supply Transformer...................33
Remote Emergency Stop Device........................... 34
Control Panel Wiring..............................................34
Volts Free Contacts ................................................. 34
Chilled Liquid Pump Starter..................................34
Run Contact ........................................................... 34
Alarm Contacts......................................................34
System Inputs .......................................................... 34
Flow Switch...........................................................34
Remote Run / Stop ................................................34
Remote Print..........................................................34
  RemoteSetpointOset–Temperature..................34
  RemoteSetpointOset–Current .........................34
Power and Control Panel Layouts
(Wye-Delta Typical) ................................................35
Option Panel Layout (Typical)...............................36
Logic Section Layout...............................................37
Logic Section Layout with Control
Panel Layout............................................................ 38
Customer Connections............................................ 39
SECTION 5COMMISSIONING
Preparation ..............................................................41
Preparation – Power O.........................................41
First Time Start-up .................................................43
SECTION 6OPERATION
General Description ................................................ 44
Start-up ....................................................................44
Normal Running and Cycling ................................ 44
Shutdown .................................................................44
SECTION 7TECHNICAL DATA
Flow Rate and Pressure Drop Charts....................45
Glycol Correction Factors ...................................... 45
Temperature and Flows ..........................................46
Physical Data (English Units)................................. 47
Physical Data (SI Units)..........................................48
Operating Limitations & Sound Power Data ....... 49
Electrical Data ........................................................50
Multiple Point Power Supply Connection.............50
Optional Single-Point Power Supply Connection
and Individual System Circuit Breakers................ 52
Optional Single-Point Power Supply Connection
with Field Supplied Circuit Protection ..................54
Optional Single-Point Power Supply
Connection to Factory Circuit Breaker..................56
Compressor Data ................................................... 57
Fan Data.................................................................57
Electrical Notes........................................................58
Wiring Diagram – Across-the-Line Start.............. 60
Elementary Diagram – Across-the-Line Start......62
Wiring Diagram – Wye-Delta Start ......................64
Elementary Diagram – Wye-Delta Start ............... 66
Control Panel Component Locations .................... 68
Power Panel Component Locations....................... 69
Connection Diagram ............................................... 70
Connection Diagram (System Wirng) ...................72
Compressor Terminal Box ..................................... 73
Dimensions ..............................................................76
YCAS0098EB - 0118EB (English) ...................... 76
YCAS0098EB - 0118EB (SI) ...............................78
YCAS0128EB (English) ..................................... 80
YCAS0128EB (SI) ...............................................82
YCAS00138EB (English) ....................................84
YCAS00138EB (SI) .............................................86
YCAS0148EB - 0178EB (English) .....................88
YCAS0148EB - 0178EB (SI)...............................90
YCAS0198EB - 0208EB (English) .....................92
YCAS0198EB - 0208EB (SI)...............................94
Clearances................................................................ 96
Operating Weights – Alum. Fin & Black Fin Coils... 97
Isolation Selection – Alum. Fin & Black Fin Coils... 98
Weight Distribution and Isolator Mounting
Positions (Alum. Fin & Black Fin Cond. Coils)....99
Operating Weights – Copper Fin Condenser Coils.
(or Aluminum Fin with Optional Silencer Kits) ....102
Isolation Selection – Copper Fin CondenserCoil (or
Aluminum Fin with Optional Silencer Kits)....... 103
Operating Weights – Copper Fin Condenser Coils
with Optional Silencer Kits .................................... 104
Isolation Selection – Copper Fin Condenser Coils
with Optional Silencer Kits .........................................105
Installation Instructions for VMC Series
AWR/AWMR and CP Restrained Mountings.....106
Refrigerant Flow Diagram ................................... 107
Process and Instrumentation Diagram ...............108
Component Locations ..........................................109
Compressor Components ..................................... 110
System Start-up Checklist .................................... 116
Unit Checks ......................................................... 116
Panel Checks ....................................................... 117
Programmed Values .............................................. 117
Initial Start-up....................................................... 118
Checking Subcooling and Superheat .................. 118
Checking Economizer Superheat......................... 119
Leak Checking....................................................... 119

6JOHNSON CONTROLS
TABLE OF CONTENTS (CONT’D)
SECTION 8MICRO PANEL CONTENTS ..................................................................................... 120
Chiller Control Panel Programming and Data Access Keys ........................................................... 120
Display and Status Information Keys................................................................................................ 120
ON / OFF Rocker Switch ..................................................................................................................... 120
Program & Setup Keys ....................................................................................................................... 120
1. INTRODUCTION & PHYSICAL DESCRIPTION ........................................................................ 121
1.1 General 121
1.2 Keypad & Display ................................................................................................................... 121
1.3 Unit (Chiller) On / OFF Switch ............................................................................................... 122
1.4 Microprocessor Board ............................................................................................................. 122
1.5 Ancillary Circuit Boards .......................................................................................................... 122
1.6 Circuit Breakers ....................................................................................................................... 123
1.7 Current Transformers (C.T.) .................................................................................................... 123
1.8 Transformers ............................................................................................................................ 123
1.9 Motor Protection Modules ....................................................................................................... 124
1.10 EMS/BAS Controls .................................................................................................................. 126
1.11 Microprocessor Board Layout .................................................................................................. 128
1.12 Logic Section Layout................................................................................................................ 129
1.13 Anti-Recycle Timer .................................................................................................................. 130
1.14 Anti-Coincidence Timer ........................................................................................................... 130
1.15 Evaporator Pump Control ......................................................................................................... 130
1.16 Compressor Heater Control ...................................................................................................... 130
1.17 Evaporator Heater Control........................................................................................................ 130
1.18 Pumpdown (LLSV) Control ..................................................................................................... 130
1.19 Alarms 130
1.20 Run Status (Chiller) .................................................................................................................. 131
1.21 Lead / Lag Compressor Selection............................................................................................. 131
2. STATUS KEY: GENERAL STATUS MESSAGES & FAULT WARNINGS.................................. 132
2.1 General 132
2.2 General Status Messages .......................................................................................................... 132
2.3 Unit Warnings ........................................................................................................................... 133
2.4 Anticipation Control Status Messages...................................................................................... 134
2.5 Unit Fault Status Messages....................................................................................................... 135
2.6 System Fault (Safety) Status Messages .................................................................................... 136
2.7 Printout on Fault Shutdown ...................................................................................................... 139
3. DISPLAY KEYS & OPTION SWITCHES ...................................................................................... 140
3.1 General 140
3.2 Chilled Liquid Temps Key........................................................................................................ 140
3.3 System # Data Keys.................................................................................................................. 141
3.4 Ambient Temp Key................................................................................................................... 141
3.5 Motor Current Key ................................................................................................................... 142
3.6 Operating HRS / Start Counter Key ......................................................................................... 142
3.7 Options Key & Dip Switch Settings......................................................................................... 142
3.8 Function Key ............................................................................................................................ 144
4. PRINT KEYS ....................................................................................................................................... 145
4.1 General 145
4.2 Oper Data Key .......................................................................................................................... 145
 4.3 OperatingData–LocalDisplayMessages............................................................................... 145
 4.4 OperatingData–RemotePrintout ........................................................................................... 146
4.5 History Key............................................................................................................................... 148
 4.6 FaultHistoryData–LocalDisplayMessages ......................................................................... 148
 4.7 FaultHistoryData–RemotePrintout ...................................................................................... 151

7
JOHNSON CONTROLS
FORM 201.18-NM7
5. ENTRY KEYS .................................................................................................................................... 152
5.1 General 152
5.2 Numerical Keypad .................................................................................................................... 152
5.3 Enter Key 152
5.4 Cancel Key152
5.5   Keys .............................................................................................................................. 152
6. SETPOINTS KEYS & CHILLED LIQUID CONTROL .................................................................. 153
6.1 General 153
6.2 Chilled Liquid Temperature Control......................................................................................... 153
6.3 Local Cooling Setpoints Key.................................................................................................... 156
6.4 Remote Cooling Setpoints Key ................................................................................................ 156
7. CLOCK KEYS .............................................................................................................................. 157
7.1 General 157
7.2 Set Time Key ............................................................................................................................ 157
7.3 Set Schedule / Holiday Key...................................................................................................... 158
7.4 Manual Override Key ............................................................................................................... 159
8. PROGRAM KEY ............................................................................................................................. 160
8.1 General 160
 8.2 ProgramKey–UserProgrammableValues ............................................................................. 160
8.3 Programming “Default” Values ................................................................................................ 164
8.4 4 Condenser Fan Control .......................................................................................................... 165
SECTION 9MAINTENANCE .......................................................................................................... 169
General Requirements ......................................................................................................................... 169
Daily Maintenance ................................................................................................................................. 169
Scheduled Maintenance ......................................................................................................................... 169
Chiller/Compressor Operating Log ........................................................................................................ 169
Compressor Unit Operation................................................................................................................. 170
Maintenance Requirements ................................................................................................................. 171
General Periodic Maintenance Checks – Standard Units ................................................................ 172
SECTION 10 SPARE PARTS .............................................................................................................. 173
Recommended Spares ............................................................................................................................ 173
Recommended Compressor Oils ............................................................................................................ 173
Associated Drawings .............................................................................................................................. 173
SECTION 11 TROUBLESHOOTING ............................................................................................... 174
Competent Persons Troubleshooting Guide ...................................................................................... 174
Sensor Calibration Charts ................................................................................................................... 176
Limited Warranty Applied Systems ................................................................................................... 177
Temperature Conversion Chart .......................................................................................................... 178
TABLE OF CONTENTS (CONT’D)

8JOHNSON CONTROLS
INTRODUCTION
YORK YCAS chillers are manufactured to the highest
design and construction standards to ensure high per-
formance, reliability and adaptability to all types of air
conditioning installations.
The unit is intended for cooling water or glycol solutions
andisnotsuitableforpurposesotherthanthosespecied
in this manual.
This manual and the Microprocessor Operating Instruc-
tions contain all the information required for correct
installation and commissioning of the unit, together with
operating and maintenance instructions. The manuals
should be read thoroughly before attempting to operate
or service the unit.
All procedures detailed in the manuals, including in-
stallation, commissioning and maintenance tasks must
only be performed by suitably trained and qualied
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 International warrants all equipment and materials
against defects in workmanship and materials for a peri-
od of one year from initial start-up, or eighteen months
fromdelivery(whicheveroccursrst)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specied.
All warranty claims must specify the unit model, serial
number, order number and run hours/starts. These details
areprintedontheunitidenticationplate.
Theunitwarrantywillbevoidifanymodicationtothe
unit is carried out without prior written approval from
York International.
For warranty purposes, the following conditions must
besatised:
• The initial start of the unit must be carried out by
trained personnel from an Authorized YORK Ser-
vice Center. See Commissioning, page 41.
• Only genuine YORK approved spare parts, oils and
refrigerants must be used. Recommendations on
spare parts can be found on page 173.
• All the scheduled maintenance operations detailed
inthismanualmustbeperformedatthespecied
timesbysuitablytrainedandqualiedpersonnel.
See Maintenance Section, page 169.
• Failure to satisfy any of these conditions will auto-
matically void the warranty. See Warranty Policy,
page 177.
SAFETY
Standards for Safety
YCAS chillers are designed and built within an ISO
9002 accredited design and manufacturing organization.
The chillers comply with the applicable sections 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
1

9
JOHNSON CONTROLS
FORM 201.18-NM7
RESPONSIBILITY FOR SAFETY
Every care has been taken in the design and manufacture
of the unit to ensure compliance with the safety require-
ments listed above. However, the individual operating or
working on any machinery is primarily responsible for:
• Personal safety, safety of other personnel, and the
machinery.
• Correct utilization of the machinery in accordance
with the procedures detailed in the manuals.
ABOUT THIS MANUAL
The following terms are used in this document to alert
the reader to areas of potential hazard.
A Warning is given in this document
to identify a hazard which could lead to
personal injury. Usually an instruction
will be given, together with a brief expla-
nation and the possible result of ignoring
the instruction.
A Cautionidentiesahazardwhichcould
lead to damage to the machine, damage to
other equipment and/or environmental pol-
lution. Usually an instruction 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 im-
plications.
The contents of this manual include suggested best
working practices and procedures. These are issued for
guidance only, and they do not take precedence over
the above stated individual responsibility and/or local
safety regulations.
This manual and any other document supplied with
the unit, are the property of YORK which reserves all
rights. They may not be reproduced, in whole or in part,
without prior written authorization from an authorized
YORK representative.
MISUSE OF EQUIPMENT
Suitability for Application
The unit is intended for cooling water or glycol solutions
andisnotsuitableforpurposesotherthanthosespecied
in these 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
operator, or damage to the equipment.
The unit must not be operated outside the design param-
etersspeciedinthismanual.
Structural Support
Structural support of the unit must be provided as in-
dicated in these instructions. Failure to provide proper
support may result in injury to the operator, or damage
to the equipment and/or building.
Mechanical Strength
The unit is not designed to withstand loads or stresses
from adjacent equipment, pipework or structures. Ad-
ditional components must not be mounted on the unit.
Any such extraneous loads may cause structural failure
and may result in injury to the operator, or damage to
the equipment.
General Access
There are a number of areas and features which may
be a hazard and potentially cause injury when working
on the unit unless suitable safety precautions are taken.
It is important to ensure access to the unit is restricted
tosuitablyqualiedpersonswhoarefamiliarwiththe
potential hazards and precautions necessary for safe
operation and maintenance of equipment containing
high temperatures, pressures and voltages.
Pressure Systems
The unit contains refrigerant vapor and liquid under
pressure, release of which can be a danger and cause
injury. The user should ensure that care is taken during
installation, operation and maintenance to avoid damage
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qualiedpersonnel.
Electrical
The unit must be grounded. No installation or main-
tenance work should be attempted on the electrical
equipmentwithoutrstswitchingOFF,isolatingand
locking-othepowersupply.Workonliveequipment
General Chiller Information & Safety

10 JOHNSON CONTROLS
mustonlybecarriedoutbysuitablytrainedandqualied
personnel. No attempt should be made to gain access to
the control panel or electrical enclosures during normal
operation of the unit.
Rotating Parts
Fanguardsmustbettedatalltimesandnotremoved
unless the power supply has been isolated. If ductwork is
tobetted,requiringthewirefanguardstoberemoved,
alternative safety measures must be taken to protect
against the risk of injury from rotating fans.
Sharp Edges
Thenning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-ammable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example,doesposeariskofasphyxiationinconned
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
10 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-
sure relief device(s). Detergents and solvents which may
cause corrosion should also be avoided.
EMERGENCY SHUTDOWN
Incaseofemergencytheelectricaloptionpanelistted
with an emergency stop switch CB3 (Circuit Breaker
3). Separate Circuit Breakers, CB1 (System 1) and
CB2 (System 2), can also be used to stop the respective
system in an emergency. When operated, it removes the
electrical supply from the control system, thus shutting
down the unit.
1

11
JOHNSON CONTROLS
FORM 201.18-NM7
SAFETY DATA R407C
Toxicity Low.
In contact with skin Liquid splashes or spray may cause freeze burns. Unlikely to be hazardous by skin absorp-
tion. Thaw a󰀨ected areas with water. Remove contaminated clothing carefully – may adhere
to skin in case of freeze burns. Wash a󰀨ected areas with plenty of warm water. If symptoms
occur (irritation or blistering) obtain medical attention.
In contact with eyes Vapor has no e󰀨ect. 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.
Ingested Highly unlikely to occur – but should this occur freeze burn will occur. Do not induce vomit-
ing. Provided patient is conscious, wash mouth with water and give about 250 ml (0.5 pint) to
drink. Obtain immediate medical attention.
Inhalation High atmospheric concentrations may have an anaesthetic e󰀨ect, including loss of
consciousness. Very high exposures may cause an abnormal heart rhythm and prove
suddenly fatal.
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 neces-
sary. Apply articial respiration if breathing has ceased or shows signs of failing. In event of
cardiac arrest apply external cardiac massage. Obtain immediate medical attention.
Further medical Symptomatic and supportive therapy is indicated. Cardiac sensitization has been described
advice which may, in the presence of circulating catecholamines such as adrenaline, give rise
to cardiac arrhythmia’s and subsequent arrest following exposure to high concentrations.
Long-term exposure A lifetime inhalation study in rats has shown that exposure to 50,000 ppm resulted in benign
tumors of the testis. This is not considered to be of relevance to humans exposed to concen-
trations at or below the occupational exposure limit.
Occupational Recommended limit: 1000 ppm v/v - 8 hr TWA.
exposure limits
Stability Not specied.
Conditions to avoid Use in presence of naked ames, red hot surfaces and high moisture levels.
Hazardous reactions May react violently with sodium, potassium, barium and other alkali and alkaline earth metals.
Incompatible materials: Magnesium and alloys containing more then 2% magnesium.
Hazardous Halogen acids by thermal decomposition and hydrolysis.
decomposition
products
General precautions Avoid inhalation of high concentrations of vapors. Atmospheric concentrations should be min-
imized 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 conned 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 re risk, direct sunlight, and all sources of
heat such as radiators. Keep at temperatures not exceeding 45°C.
Protective clothing Wear overalls, impervious gloves and goggles/face protection.
Spill/leak procedure 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 spillage’s to evaporate provided there
is suitable ventilation.
Large spillages: Ventilate area. Contain spillage’s with sand, earth or any suitable absorbent
material. Prevent liquid from entering drains, sewers, basements and work pits since vapor
may create a su󰀨ocating 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 Non-ammable at atmospheric conditions.
data
Containers Fire exposed containers should be kept cool with water sprays. Containers may burst if over-
heated.
Fire ghting Self contained breathing apparatus and protective clothing must be worn in
protective equipment re conditions.
REFRIGERANT DATA: MATERIAL SAFETY DATA
General Chiller Information & Safety

12 JOHNSON CONTROLS
SAFETY DATA YORK “L” OIL
Classication Non-hazardous
In contact with skin Minimally irritating. No rst aid necessary. Exercise reasonable personal cleanliness including
cleansing exposed skin areas several times daily with soap and water. Launder soiled work
clothes at least weekly.
In contact with eyes Flush eyes with eyewash solution or clean water for 15 minutes and consult a physician.
Ingested May cause nausea and diarrhea. Obtain immediate medical attention.
Inhalation If oil mist is inhaled, remove to fresh air and consult a physician.
Occupational Not determined.
exposure limits
Stability Stable but hygroscopic - store in sealed containers.
Conditions to avoid Strong oxidizers, caustic or acid solutions, excessive heat. May degrade some paints and
rubber materials.
Hazardous Not fully, Analogous compounds evolve carbon monoxide, carbon dioxide and other
decomposition unidentied fragments when burned. Burning may evolve irritating/noxious fumes.
Respiratory protection Use in well ventilated areas - ventilate locally.
Protective clothing Goggles or face shield should be worn. Gloves not necessary, but recommended, especially
for prolonged exposure.
Spill / Leak procedure Wear suitable protective equipment. Especially goggles. Stop source of spill. Use absorbent
materials to soak up uid (i.e. sand, sawdust and commercially available materials).
Disposal Incinerate the oil and all associated wastes in an approved facility in accordance with local
laws and regulations governing oily wastes.
Fire extinguishing Flash point over 300°C. Use dry chemical, carbon dioxide or foam. Spraying water on hot or
data burning liquid may cause frothing or splashing.
If a leak or spill has not ignited use water spray to disperse the vapors and to provided protec-
tion for persons attempting to stop the leak.
Containers Fire exposed containers should be kept cool with water sprays.
Fire ghting Self contained breathing apparatus should be worn in re conditions.
protective equipment
REFRIGERANT OIL DATA:
MATERIAL SAFETY DATA
1

13
JOHNSON CONTROLS
FORM 201.18-NM7
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
Specic 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
Flammable Limits: Not Established
Auto-Ignition Temperature: no data
HMIS Ratings:
Health: 0
Flammability: 1
Reactivity: 0
Extinguishing Media: Dry chemical; CO2 foam; water fog (see below)
Unusual Fire and Explosion Hazards: None
Special Fire Fighting Techniques: Burning uid may evolve irritating/noxious fumes.
Fireghters should use NIOSH/MNSA-approved self-contained breath-
ing apparatus. Use water fog to cool re-exposed containers. USE
WATER CAREFULLY NEAR EXPOSED/BURNING LIQUIDS. May
cause frothing and splashing of hot materials.
General Chiller Information & Safety

14 JOHNSON CONTROLS
Section 6 – REACTIVITY DATA
Stability: Stable
Hazardous Polymerization: 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 unidentied 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 phy-
sician.
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
Respiratory Protection: Use in well ventilated area
Ventilation: Local exhaust
Protective Gloves: Strongly recommended, especially for prolonged exposure.
Eye/Face Protection: Goggles
Fireghters should use NIOSH/MNSA-approved self-contained breathing apparatus. Use water fog to cool re-ex-
posed 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: Wear suitable protective equipment, especially goggles. Stop source of spill. Dike spill area. Use
absorbent materials to soak up uid (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
otherwise exposed to this product. YORK believes the information in this document to be reliable and up to date as
of the date of publication, but makes no guarantee that it is.
1

15
JOHNSON CONTROLS
FORM 201.18-NM7
INTRODUCTION
YORK YCAS chillers are designed for water or wa-
ter-glycol cooling. All units are designed to be located
outside on the roof of a building or at ground level.
The units are completely assembled with all intercon-
necting refrigerant piping and internal wiring, ready for
eld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 owing
through the cooler to ensure that each refrigerant circuit
operates correctly.
The unit structure is manufactured from heavy gauge,
galvanized steel. All external structural parts are coated
with “Desert Sand” baked-on enamel powder paint. This
providesanish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 (equivalent
to ASTM D1654 rating of “6”).
All exposed power wiring is be routed through liq-
uid-tight, non-metallic conduit.
General Description
The Air Cooled Screw Chiller utilizes many components
which are the same or nearly the same as a standard
reciprocating chiller of a similar size. This includes
modular frame rails, condenser, fans and evaporator.
The chiller consists of 2 screw compressors in a corre-
sponding number of separate refrigerant circuits, a single
shellandtubeDXcounterow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eciencies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 60 Hz motor
operates at 3550 RPM to direct drive the male rotor
whichinturndrivesthefemalerotoronalightlmofoil.
PRODUCT DESCRIPTION
FIG. 1 – COMPONENT LOCATIONS
1 System Fans
2 System 1 Power Panel
3 System 2 Power Panel
4 Control Panel
5 Power Entry
6 System 1 Compressor
7 Cooler
8 System 2 Compressor
9 System 1 Condenser
10 Option Box
4
10
23
1
8
7
65
9
28971AR
Product Description

16 JOHNSON CONTROLS
Refrigerant gas is injected into the void created by the
unmeshingofthevelobedmaleandsevenlobedfe-
male rotor. Further meshing of the rotors closes the rotor
threads to the suction port and progressively compresses
the gas in an axial direction to the discharge port. The
gas is compressed in volume and increased in pressure
before exiting at a designed volume at the discharge end
of the rotor casing. Since the intake and discharge cycles
overlap,aresultingsmoothowofgasismaintained.
The rotors are housed in a cast iron compressor housing
precision machined to provide optimal clearances for
the rotors. Contact between the male and female rotor
is primarily rolling on a contact band on each of the
rotor’s pitch circle. This results in virtually no rotor
wear and increased reliability, a trademark of the screw
compressor.
The compressor incorporates a complete anti-friction
bearing design for reduced power input and increased
reliability. Four separated, cylindrical, roller bearings
handle radial loads. Angular-contact ball bearings han-
dle axial loads. Together they maintain accurate rotor
positioning at all pressure ratios, thereby minimizing
leakageandmaintainingeciency.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 evap-
oratorowingacrossthemotor.Redundantoverload
protection is provided using both thermistor and current
overload protection.
The compressor is lubricated by removing oil from the
refrigerant using an external oil separator. The pressur-
ized oil is then cooled in the condenser coils and piped
back to the compressor for lubrication. The compressor
design working pressure is 450 PSIG (31 bar). Each
chiller receives a 300 PSIG (21 bar) low side and a 450
PSIG (31 bar) high side factory test. A 350 watt (115-
1-60) cartridge heater is located in the compressor. The
heater is temperature activated to prevent refrigerant
condensation.
The following items are also included:
• Internal discharge check valve to prevent rotor
backspin or shutdown.
 • Anacousticallytuned,internaldischargemuerto
minimizenoise,whileoperatingowformaximum
performance.
 • Dischargeandsuctionshutovalves.
• A rain-tight terminal box.
• A suction gas screen and serviceable, 0.5 micron
fullowoillterwithinthecompressorhousing.
Evaporator
ThesystemusesahigheciencyShellandTubetype
Direct Expansion Evaporator. Each of the 2 refrigerant
circuits consists of 4 passes with the chilled liquid cir-
culating back and forth across the tubes from one end
to the other.
The design working pressure of the cooler on the shell
side is 150 PSIG (10 bar), and 350 PSIG (24 bar) for the
tube(refrigerantside).Thewaterbaesarefabricated
from galvanized steel to resist corrosion. Removable
heads are provided for access to internally enhanced,
seamless, copper tubes. Water vent and drain connec-
tions are included.
The cooler is equipped with a thermostatically controlled
heater for protection to -20°F (-29°C) ambient and
insulatedwith3/4”(19mm)exibleclosed-cellfoam.
The water nozzles are provided with grooves for
mechanical couplings and should be insulated by the
contractor after pipe installation.
Condenser
Thenandtubecondensercoilsaremanufacturedfrom
seamless,internallyenhanced,highcondensingcoe-
cient, corrosion resistant copper tubes arranged in stag-
FIG. 2 – SCREW COMPRESSOR
00485VIP
2

17
JOHNSON CONTROLS
FORM 201.18-NM7
gered rows and mechanically expanded into corrosion
resistantaluminumalloynswithfullheightncollars.
They have a design working pressure of 450 PSIG
(31 bar). Each coil is rested to 495 PSIG (34 bar).
Multiple fans move air through the coils. They are
dynamically and statically balanced, direct drive with
corrosion resistant glass ber reinforced composite
blades molded into low noise, full airfoil cross section,
providingverticalairdischargefromextendedorices
foreciencyandlowsound.Eachfanislocatedina
separatecompartmenttopreventcrossowduringfan
cycling. Guards of heavy gauge, PVC coated galvanized
steel are provided.
Thefanmotorsarehigheciency,directdrive,6-pole,
3-phase, Class- “F,” current overload protected, totally
enclosed (TEAO) type with double sealed, permanently
lubricated ball bearings.
Oil Separator/System
The external oil separator, with no moving parts and
designed for minimum oil carry-over, is mounted in
the discharge line of the compressor. The high pressure
discharge gas is forced around a 90 degree bend. Oil is
forced to the outside of the separator through centrifugal
action and captured on wire mesh where it drains to the
bottom of the oil separator and into the compressor.
Theoil(YORK“L”oil–aPOEoilusedforallrefriger-
ant applications), which drains back into the compressor
throughareplaceable0.5-3.0micronoillter,andoil
supply solenoid, is at high pressure. This high pressure
“oil injection” forces the oil into the compressor where
it is gravity fed to the gears and bearings for lubrication.
After lubricating the gears and bearings, it is injected
throughoricesonaclosedthreadnearthesuctionend
of the rotors. The oil is automatically injected because
ofthepressuredierencebetweenthedischargepres-
sure and the reduced pressure at the suction end of the
rotors. This lubricates the rotors as well as provides
an oil seal against leakage around the rotors to assure
refrigerant compression (volumetric e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ows
into the rotors at a point about 1.2x suction. This assures
thatarequiredminimumdierentialofatleast30PSID
(2.1 bar) exists between discharge and 1.2x suction, to
force oil into rotor case, a minimum of 10 PSID (0.6
bar) is all that is required to assure protection of the
compressor. Oil pressure safety is monitored as the
dierencebetweensuctionandthepressureoftheoil
entering the rotor case.
Maximum working pressure of the oil separator is 450
PSIG (31 bar). A relief valve is installed in the oil sep-
arator 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 liq-
uid injection activated by the microprocessor, utilizing
a discharge temperature sensor, and a solenoid valve.
Oil Cooling
Oil cooling is provided by routing oil from the oil sep-
arator through several of the top rows of the condenser
coils and back to the compressor.
Capacity Control
The compressors will start at the minimum load position
and provide a capacity control range from 10% - 100% of
the full unit load using a continuous function slide valve.
The microprocessor modulates the current signal to a
3-way pressure regulating capacity control valve which
controls command compressor capacity, independent of
system pressures, and balances the compressor capacity
with the cooling load. Loading is accomplished by vary-
ing pressure through the pressure regulating capacity
control valve to move the slide valve against the spring
pressure to promote stable smooth loading.
Automatic spring return of the slide valve to the min-
imum load position will ensure compressor starting at
minimum motor load.
Power and Control Panel
All controls and motor starting equipment are factory
wired and function tested. The panel enclosures are
designed to IP55 and are manufactured from powder
painted galvanized steel.
Product Description

18 JOHNSON CONTROLS
The Power and Control Panel are divided into power
sections for each compressor and associated fans, a con-
trol section and an electrical options section. The power
and control sections have separate hinged, latched, and
gasket sealed doors equipped with wind struts.
Each power compartment contains:
Compressor and fan starting contactors, fan motor
external overloads, control circuit serving compressor
capacity control, compressor and fan contactor coils and
compressor motor overloads.
The current transformers for the compressor motor
overloads sense each phase, as an input to the micro-
processor. This protects the compressor motors from
damage due to: low current input, high input current,
unbalanced current, single phasing, phase reversal, and
compressor locked rotor.
The control section contains:
ON/OFF switch, microcomputer keypad and display,
microprocessor board, I/O expansion board, relay boards
and power supply board.
The options sections contain:
A control circuit transformer complete with service
switch providing 115/1/60 Hz power to the unit control
system.
Electrical options as described in “Accessories and
Options.”
Microprocessor Controls
The microprocessor has the following functions and
displays:
• A liquid crystal 40 character display with text pro-
vided on two lines and light emitting diode back-
lighting outdoor viewing.
• A color coded, 35 button, sealed keypad with sec-
tions for Display, Entry, Setpoints, Clock, Print,
Program and Unit ON/OFF.
The standard controls shall include: brine chilling, ther-
mal storage, automatic pump down, run signal contacts,
demand load limit from external building automation
system input, remote reset liquid temperature reset
input, unit alarm contacts, chilled liquid pump control,
automatic reset after power failure, automatic system
optimization to match operating conditions.
The software is stored in non-volatile memory (EPROM)
to eliminate chiller failure due to AC power failure.
The Programmed Setpoint is stored in lithium battery
backed 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 accom-
plished by sending 3-phase current signals proportional
to motor current from the Motor Protector module to the
Power Supply Board where the signals are conditioned
and routed to the I/O Expansion board to be multi-
plexed and sent to the Microprocessor Board. If the
motor current exceeds the 115% FLA trip point after
3 seconds of operation on either Wye-Delta or ACL
starters, the micro will shut the system down and lock
it out after one fault. A manual reset of the respective
system switch is required to clear the fault and restart
the system. A thorough check of the motor, wiring, and
refrigerant system should be done before restarting a
system that has faulted on high motor current.
The micro also provides low motor current protection
when it senses a motor current less than 10% FLA. The
micro will shut the system down whenever low motor
current is sensed and will lock out a system if three faults
occur in 90 minutes. Low motor current protection is ac-
tivated 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 system switch. See
also Motor Protection Module section below.
The micro senses low motor current whenever a HPCO
or Motor Protector contact opens. This occurs because
the 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.
2

19
JOHNSON CONTROLS
FORM 201.18-NM7
Motor Protection Module
The mechanical motor protector is a Texas Instruments
2ACE Three Phase Protection Module (Fig. 45, page
125) thermal and current motor overload protection.
This module protects against phase to phase current im-
balance, 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ashing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.
0 Normal - no fault detected (Running)
Flashing “0” Motor o󰀨 or unloaded < 5A (Running)
AC current level.
1 High current fault.
2 Loaded phase to phase current
imbalance > 17%.
3 Unloaded phase to phase current
imbalance > 25%.
4 Improper incoming phase rotation.
5 High motor temperature. Trip point =
13kW, reset = 3.25kW.
6 Communication error.
7 Unload imbalance ( > 50%)
8 Phase Loss (> 60%)
E Out of range of RLA calibration.
Other symbols Defective module or supply voltage.
Working voltage 18 - 30 VAC, 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
motor to stop. The micro senses the low motor current
and shuts the system down. The micro will try two
more starts before locking the system out. The system
locks out because the motor protector is a manual
resetdevice.Aftertherststartthemodules’contacts
will be open preventing the motor contactors from
energizing. Power must be removed and reapplied to
reset the module.
Current Overload
The 2ACE module design uses one integral current
transformer per phase to provide protection against
rapid current overload conditions. The module responds
to changes in current and must be calibrated using DIP
switches located on the module. Integral trip curves
allow for in-rush currents during Wye-Delta, part wind,
or ACL starts without nuisance tripping.
To check the factory setting of the 2ACE module current
overload trip value. See Table 1 (pages 20 and 21).
For the location of the dip switches and determining the
ON position refer to the “Note” below and Figure 45.
For the location of the dip switches and determining the
ON side of the switches, refer to Figure 45, page 125. As
indicated, to place a switch in the ON position requires
pushing the switch to the left.
A switch must be pushed to the left to
place the switch in the ON position.
It is recommended that an YORK
Service Technician or the YORK
factory be consulted before changing
these settings for any reason, since
damage to the compressor could re‑
sult. Changes should never be made
unless it is veried that the settings
are incorrect.
Anytime a dip switch change is made,
power must be cycled o and on to the
module to reprogram the module to the
new valve.
Product Description

20 JOHNSON CONTROLS
Thermal Overload
ThreePTC(positivetemperaturecoecient)thermistors
in the motor windings of each phase provides thermal
protection. The sensor resistance stays relatively con-
stant at 1kΩuntil a temperature of 266°F (130°C) 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 “Oper-
ating Current” to the measured half line current. The
“Operating 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 circuit
being de-energized.
Imbalance isdened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
response time.
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