York YCRS Series Installation and operating instructions

INSTALLATION, OPERATION AND
MAINTENANCE
YCRS
WATER COOLED LIQUID CHILLERS
New Release Form 201.25-NM1 (302)
60 HERTZ
STYLE A
REFRIGERANT TYPE: R-22
YCRS WATER COOLED REMOTE CONDENSER
YCRS0100SC – 0240SC
81 TONS THROUGH 194 TONS
(285 KW THROUGH 682 KW)
00635VIP

YORK INTERNATIONAL
2
FORM 201.25-NM1 (302)

FORM 201.25-NM1 (302)
3
YORK INTERNATIONAL
SECTION 1GENERAL CHILLER INFORMATION
& SAFETY
Introduction ............................................................... 6
Warranty ................................................................... 6
Safety ......................................................................... 6
Standards for Safety ............................................... 6
Responsibility for Safety .......................................... 7
About this Manual ..................................................... 7
Misuse of Equipment ................................................. 7
Suitability for Application ...................................... 7
Structural Support .................................................. 7
Mechanical Strength .............................................. 7
General Access ...................................................... 7
Pressure Systems ................................................... 7
Electrical ................................................................. 7
Refrigerants and Oils .............................................. 8
High Temperature and Pressure Cleaning .............. 8
Emergency Shutdown ................................................ 8
SECTION 2 PRODUCT DESCRIPTION
Introduction ............................................................... 9
Compressor ............................................................ 9
Motor Starting ...................................................... 10
Capacity Control .................................................. 10
Oil Separator ........................................................... 11
Oil Cooler ................................................................. 11
Refrigerant Circuits ............................................... 11
Condenser ............................................................... 11
Cooler ....................................................................... 11
Power and Control Panels ....................................... 12
Microprocessor Controls ........................................ 12
Motor Current Protection ....................................... 12
Motor Protector Module ...................................... 13
Current Overload .................................................. 13
Thermal Overload ................................................. 13
Current Unbalance / Loss of Phase...................... 13
Improper Phase Sequence .................................... 13
Keypad Controls ..................................................... 13
Status Key ............................................................ 13
Display Keys ........................................................ 14
Print Keys .............................................................. 14
Entry Keys ........................................................... 14
Setpoints Keys ..................................................... 14
Clock Keys ........................................................... 14
Program Key ......................................................... 14
Accessories and Options ....................................... 14
Alternative Refrigerants ........................................ 14
Electrical Options ................................................... 14
Accessories ............................................................ 15
Aternative Chilled Fluid Applications ................. 15
Nomenclature ......................................................... 16
Functional Description .......................................... 16
SECTION 3TRANSPORTATION, HANDLING
AND STORAGE
Delivery and Storage .............................................. 17
Inspection ............................................................... 17
Moving the Unit ...................................................... 17
Lifting by Crane / Hoist ........................................ 17
Lifting by Fork Lift ............................................... 18
Control Panel Removal .......................................... 18
Lifting Weights ...................................................... 18
SECTION 4INSTALLATION
Location Requirements .......................................... 19
Installation of Vibration Isolators ......................... 19
Pipework Connection ............................................. 19
General Requirements ........................................... 19
Water Treatment .................................................... 20
Glycol Solutions ................................................... 20
Pipework Arrangement ......................................... 21
Recommendations of the Building Services
Research Association .......................................... 21
Connection Types & Sizes ..................................... 21
Cooler Connections.............................................. 21
Option Flanges ..................................................... 22
Refrigerant Relief Valve Piping ............................ 22
Condenser Cooling Liquid Systems ...................... 22
Condenser Piping ................................................... 22
Discharge Lines.................................................... 22
Liquid Lines ........................................................... 22
Electrical Connection ............................................. 24
Power Wiring ......................................................... 24
Units with Single-Point Power Supply Wiring ..... 24
Units with Multi-Point Power Supply Wiring ...... 24
Control Transformer Primary Voltage Tappings ... 25
Remote Emergency Stop Device .......................... 25
Common Input Section Wiring .............................. 25
Chilled Liquid Pump ............................................. 25
Common Run Signal ............................................. 25
System Alarm ....................................................... 25
Control Panel Wiring ............................................ 25
Flow Switch .......................................................... 25
Remote Run / Stop ............................................... 26
Remote Print (PNT) ............................................... 26
Remote Setpoint Offset – Temperature ................ 26
Remote Setpoint Offset – Current ........................ 26
TABLE OF CONTENTS

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FORM 201.25-NM1 (302)
TABLE OF CONTENTS (CONT’D)
Customer Wiring Data .......................................... 27
Connection Diagram Legend and Notes ................. 28
SECTION 5COMMISSIONING
Commissioning ...................................................... 29
Preparation ........................................................... 29
Preparation – Power Off ....................................... 29
First Time Start-up ................................................ 31
SECTION 6UNIT OPERATION
Unit Operation ........................................................ 32
General Description .............................................. 32
Start-up ................................................................... 32
Normal Running and Cycling ................................ 32
Shutdown ................................................................ 32
SECTION 7MICROPANEL
1. Introduction and Descriptions ................................ 33
1.1 System Switches 1-2 ...................................... 33
1.2 Internal Clock & Memory Backup Battery .... 33
1.3 Power Supply Board ...................................... 33
1.4 Input / Output Expansion Board ................... 33
1.5 Relay Output Board ....................................... 33
1.6 Circuit Breakers .............................................. 34
1.7 Current Transformers (C.T.) ........................... 34
1.8 Transformers ................................................. 34
1.9 Motor Protector Modules .............................. 34
1.10 Logic Section ................................................. 34
1.11 Remote Start / Stop ........................................ 35
1.12 Remote Current Reset .................................... 35
1.13 Remote Setpoint Reset .................................. 36
1.14 Control Panel ................................................. 37
1.15 Remote Emergency Stop Device ................... 37
1.16 Common Input Power Section
Voltage Free Contacts .................................... 37
1.17 Alarm Contacts .............................................. 37
1.18 Chilled Liquid Pump Contact ......................... 37
1.19 Run Contact ................................................... 37
1.20 Anti-Recycle Timer ........................................ 37
1.21 Anti-Coincidence Timer ................................. 38
1.22 Compressor Heater Control ............................ 38
1.23 Pumpdown (LLSV) Control ............................ 38
1.24 Lead / Lag Compressor Selection ................... 38
2. CONTROL PANEL PROGRAMMING AND
DATA ACCESS ....................................................... 39
2.1 Display and Status Keys .............................. 39
2.2 Program and Setup Keys .............................. 39
3. STATUS KEYS ......................................................... 40
3.1 General ........................................................... 40
3.2 General Status Messages .............................. 40
3.3 Unit Warnings ............................................... 41
3.4 Anticipation Control Status Messages ........ 42
3.5 Unit Fault Status Messages .......................... 43
3.6 System Fault Status Messages .................... 44
3.7 Printout on Fault Shutdown .......................... 47
4. DISPLAY KEYS ....................................................... 48
4.1 General ........................................................... 48
4.2 Chilled Liquid Temps Key .............................. 48
4.3 System Data Keys ......................................... 48
4.4 Ambient Temp Key ........................................ 49
4.5 Motor Current Key ........................................ 49
4.6 Operating Hrs / Start Counter Key ................ 50
4.7 Options Key and Dip Switch Settings ........... 50
4.8 DIP Switch Settings ....................................... 51
4.9 Function Key ................................................. 51
5. PRINT KEYS ............................................................ 52
5.1 General ........................................................... 52
5.2 Oper Data Key ............................................... 52
5.3 Oper Data – Local Display Messages ........... 52
5.4 Oper Data – Remote Printout......................... 54
5.5 History Key ................................................... 55
5.6 History – Local Display Messages ............... 55
5.7 History – Remote Printout ............................. 58
5.8 Local Printer Option ....................................... 59
6. ENTRY KEYS ........................................................... 61
6.1 General ........................................................... 61
6.2 Numerical Keypad ......................................... 61
6.3 Enter Key ....................................................... 61
6.4 Cancel Key .................................................... 61
6.5  Keys ...................................................... 61
7. SETPOINT KEYS AND CHILLED
LIQUID CONTROL ................................................. 62
7.1 General ........................................................... 62
7.2 Chilled Liquid Temperature Control ............... 62
7.3 Slide Valve Control ........................................ 63
7.4 Load Timers ................................................... 63
7.5 Slide Valve Position ....................................... 63
7.6 Compressor Starting and Loading Sequence 63
7.7 Compressor Loading ..................................... 64
7.8 Loading Limiting ............................................ 64
7.9 Compressor Unloading and
Shutdown Sequence ...................................... 64
7.10 Local Cooling Setpoints Key......................... 64
7.11 Remote Cooling Setpoints Key ..................... 65
8. CLOCK KEYS .......................................................... 66
8.1 General ........................................................... 66
8.2 Set Time / Date Key ....................................... 66
8.3 Set Schedule / Holiday Key ........................... 67
8.4 Manual Override Key .................................... 68
9. PROGRAM KEYS .................................................... 69
9.1 General ........................................................... 69
9.2 User Programmable Values ............................. 69
9.3 Input /Output Display Routine...................... 72

FORM 201.25-NM1 (302)
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YORK INTERNATIONAL
TABLE OF CONTENTS (CONT’D)
10. EMS / BAS INTERFACE CARD KITS .................... 74
10.1 EMS / BAS Remote Temperature Reset ......... 74
10.2 BAS / EMS Remote Temperature
Reset Option .................................................. 74
SECTION 8 MAINTENANCE
General Requirements ............................................. 75
Daily Maintenance ................................................... 75
Scheduled Maintenance ........................................... 75
Standard Units ......................................................... 77
Troubleshooting Guide .............................................. 78
Sensor Calibration Charts ...................................... 80
Typical Control Panel Wiring .................................. 82
SECTION 9 TECHNICAL DATA
Flow Rate and Pressure Drop Graphs ..................... 84
Physical Data / Sound Data ..................................... 87
Electrical Data ......................................................... 88
Dimensions .............................................................. 94
Isolator Selection Data ............................................. 98
Isolator Details ......................................................... 99
Sound Data .............................................................. 100
Compressors .......................................................... 101
SECTION 10 SPARE PARTS
Recommended Spare Parts ...................................... 102
Recommended Compressor Oils .............................. 102
Associated Drawings .............................................. 102
SECTION 11 DECOMMISSIONING,
DISMANTLING AND DISPOSAL
General ..................................................................... 103

YORK INTERNATIONAL
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FORM 201.25-NM1 (302)
INTRODUCTION
YORK YCRS 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 solu-
tions and is not suitable for purposes other than those
specified in this manual.
This manual contains all the information required for
correct installation and commissioning of the unit, to-
gether with operating and maintenance instructions.
This manual should be read thoroughly before attempt-
ing 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 International warrants all equipment and materi-
als against defects in workmanship and materials for a
period of one year from initial start-up, or eighteen
months from delivery (whichever occurs first) unless
extended warranty has been agreed upon as part of the
contract.
The warranty is limited to parts only replacement and
shipping of any faulty part, or sub-assembly which has
failed due to poor quality or manufacturing errors. All
claims must be supported by evidence that the failure
has occurred within the warranty period, and that the
unit has been operated within the designed parameters
specified.
All warranty claims must specify the unit model, serial
number, order number and run hours/starts. These de-
tails are printed on the unit identification plate.
The unit warranty will be void if any modification to the
unit is carried out without prior written approval from
York International.
For warranty purposes, the following conditions must
be satisfied:
• The initial start of the unit must be carried out by
trained personnel from an Authorized YORK Ser-
vice Center. See Commissioning, page 29.
• Only genuine YORK approved spare parts, oils and
refrigerants must be used.
• 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 76.
• Failure to satisfy any of these conditions will auto-
matically void the warranty.
SAFETY
Standards for Safety
YCRS chillers are designed and built within an ISO
9002 accredited design and manufacturing organiza-
tion. 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
General Chiller Information & Safety

FORM 201.25-NM1 (302)
7
YORK INTERNATIONAL
1
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-
sponsible 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 per-
sonal injury. Usually an instruction will be
given, together with a brief explanation
and the possible result of ignoring the in-
struction.
A Caution identifies a hazard which
could lead to damage to the machine,
damage to other equipment and/or envi-
ronmental pollution. Usually an instruc-
tion will be given, together with a brief
explanation and the possible result of ig-
noring the instruction.
A Note is used to highlight additional infor-
mation 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, are the property of YORK which reserves all rights.
They may not be reproduced, in whole or in part, with-
out 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 specified
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 op-
erator, or damage to the equipment.
The unit must not be operated outside the design pa-
rameters specified in this manual.
Structural Support
Structural support of the unit must be provided as indi-
cated in these instructions. Failure to provide proper
support may result in injury to the operator, or damage
to the equipment and/or building.
Mechanical Strength
The unit is not designed to withstand loads or stresses
from adjacent equipment, pipework or structures. Ad-
ditional components must not be mounted on the unit.
Any such extraneous loads may cause structural fail-
ure and may result in injury to the operator, or damage
to the equipment.
General Access
There are a number of areas and features which may
be a hazard and potentially cause injury when working
on the unit unless suitable safety precautions are taken.
It is important to ensure access to the unit is restricted
to suitably qualified persons who are familiar with the
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 pres-
sure, release of which can be a danger and cause injury.
The user should ensure that care is taken during instal-
lation, operation and maintenance to avoid damage to
the pressure system. No attempt should be made to gain
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 with out first switching OFF, isolating and lock-
ing-off the power supply. Work on live equipment must

YORK INTERNATIONAL
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FORM 201.25-NM1 (302)
only be carried out by suitably trained and qualified per-
sonnel. No attempt should be made to gain access to
the control panel or electrical enclosures during normal
operation of the unit.
Refrigerants and Oils
Refrigerants and oils used in the unit are generally non-
toxic, non-flammable and non-corrosive, and pose no
special safety hazards. Use of gloves and safety glasses
are, however, recommended when working on the unit.
The build up of refrigerant vapor, from a leak for ex-
ample, does pose a risk of asphyxiation in confined or
enclosed spaces and attention should be given to good
ventilation.
High Temperature and Pressure Cleaning
High temperature and pressure cleaning methods (e.g.
steam cleaning) should not be used on any part of the
pressure system as this may cause operation of the pres-
sure relief device(s). Detergents and solvents which may
cause corrosion should also be avoided.
EMERGENCY SHUTDOWN
In case of emergency the electrical option panel is fitted
with an emergency stop switch CB3 (Circuit Breaker
3). Separate Circuit Breakers, CB1 (System 1) and CB2
(System 2), can also be used to stop the respective sys-
tem in an emergency. When operated, it removes the
electrical supply from the control system, thus shutting
down the unit.
General Chiller Information & Safety

FORM 201.25-NM1 (302)
9
YORK INTERNATIONAL
INTRODUCTION
YORK YCRS chillers are designed for water or wa-
ter-glycol cooling.
All models are designed for indoor installation. The units
are completely assembled with all interconnecting re-
frigerant piping and internal wiring, ready for field in-
stallation.
The unit consists of 2 screw compressors in a correspond-
ing number of separate refrigerant circuits, a shell and
tube DX evaporator, and oil separators for each circuit.
Before delivery, the unit is pressure tested, evacuated,
and fully charged with refrigerant and oil in each of the
independent refrigerant circuits. After assembly, an
operational test is performed with water flowing through
the cooler to ensure that each refrigerant circuit oper-
ates correctly.
The unit is shipped with a nitrogen holding charge. Re-
frigerant (R-22) must be added on site.
The unit framework is fabricated using heavy-gauge
galvanized steel which is zinc phosphate pre-treated and
powder coated to minimize corrosion.
Compressor
Twin helical semi-hermetic screw compressors, are
provided to ensure high operational efficiencies and re-
liable performance. Capacity control is achieved through
a single slide valve. The compressor is a positive dis-
placement type characterized by two helically grooved
rotors which are manufactured from forged steel. The
60 Hz motor operates at 3600 rpm to direct drive the
male rotor which in turn drives the female rotor on a
light film of oil.
Each compressor is direct drive, semi-hermetic, rotary
twin screw type and includes the following items:
Two screw rotors, with asymmetric profiles, manufac-
tured from forged steel.
A cast iron compressor housing precision machined to
provide optimal clearance for the rotors.
An internal discharge check valve to prevent rotor back-
spin during shutdown.
An acoustically tuned, internal discharge muffler to
minimize noise, while optimizing flow for maximum
performance.
Discharge and suction shut-off service valves.
A reliable suction gas cooled high efficiency, accessible
hermetic motor with redundant overload protection using
both thermistor and current overload protection.
A suction gas screen and serviceable, 0.5 micron full
flow oil filter within the compressor housing.
Refrigerant gas is injected into the void created by the
unmeshing of the five lobed male and seven lobed fe-
male rotor. Further meshing of the rotors closes the rotor
threads to the suction port and progressively compresses
the gas in an axial direction to the discharge port. The
SECTION 2
PRODUCT DESCRIPTION
1 COMPRESSOR
2 COOLER
3 POWER SECTION - SYSTEM 1
4 COMMON INPUT SECTION
5 POWER SECTION - SYSTEM 2
6 CONTROL PANEL
FIG. 1 – YCRS WATER COOLED LIQUID CHILLER
2
2
1
6
543
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00635VIP

YORK INTERNATIONAL
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FORM 201.25-NM1 (302)
gas is compressed in volume and increased in pressure
before exiting at a designed volume at the discharge end
of the rotor casing. Since the intake and discharge cycles
overlap, a resulting smooth flow of gas is maintained.
The rotors are housed in a cast iron compressor hous-
ing precision machined to provide optimal clearances
for the rotors. Contact between the male and female
rotor is primarily rolling on a contact band on each of
the rotor’s pitch circle. This results in virtually no ro-
tor wear and increased reliability.
The compressor incorporates a complete anti-friction
bearing design for reduced power input and increased
reliability. Four separated, cylindrical, roller bearings
handle radial loads. Angular-contact ball bearings
handle axial loads. Together they maintain accurate
rotor positioning at all pressure ratios, thereby mini-
mizing leakage and maintaining efficiency. A springless
check valve is installed in the compressor discharge
housing to prevent compressor rotor backspin due to
system refrigerant pressure gradients during shutdown.
Motor cooling is provided by suction gas from the
evaporator flowing across the motor. Redundant over-
load protection is provided using both thermistor and
current overload protection.
The compressor is lubricated by removing oil from the
refrigerant using an external oil separator.
A 350 watt (115V 1 Ø 60 Hz) immersion heater is lo-
cated in the compressor. The heater is temperature ac-
tivated to prevent refrigerant condensation.
Motor Starting
Compressor motor starting is Star/Delta (S/D) open
transition. The starter utilizes 3 motor contactors, a tran-
sition delay relay and a start relay. The starter allows
inrush current to be limited to approximately 33% LRA
for the first 4 to 10 seconds, with current increasing to
normal running current when the Delta connection is
completed.
When the microprocessor initiates a start signal to run
a compressor, the applicable relays are energized. The
transition of the relay contacts enable the ‘Star’ con-
nection of the motor start. The ‘Star’ connection of the
motor start is enabled for 4 to 10 seconds depending
upon motor current as sensed by the microprocessor.
Normally, the transition to Delta takes 10 seconds if
current is below 125% FLA. If motor current exceeds
125% FLA, the transition is made to Delta as long as
the “Star” has been enabled for at least 4 seconds.
Capacity Control
The compressors will start at the minimum load posi-
tion and provide a capacity control range from 10% to
100% per compressor using a continuous function slide
valve. The microprocessor controlled output pressure
regulating capacity control valve will command com-
pressor capacity independent of control valve input pres-
sure and balance the compressor capacity with the cool-
ing load.
FIG. 2 – SCREW COMPRESSOR
Product Description
LD03668
SUCTION
GAS IN
MOTOR
TERMINALS
LIFTING LUG
THREADED HOLE
OIL
HEATER
ECONOMIZER
GAS IN
DISCHARGE CASE OIL INLET FROM CONDENSER CODING COIL
DISCHARGE GAS
OUT
OIL FILTER BLEED &
EVACUATION POINT
OIL FILTER
COVER PLATE
CAPACITY CONTROL SOLENOID
(CAPACITY CONTROL, 3-WAY VALVE,
IS LOCATED UNDER THE SOLENOID)
LIFTING LUG
THREADED
HOLE
OIL PRESSURE
TRANSDUCER
LOCATION
ROTOR
STATOR
LOCKING BOLT

FORM 201.25-NM1 (302)
11
YORK INTERNATIONAL
The automatic spring return of the capacity control valve
to the minimum load position will ensure compressor
starting at minimum motor load.
OIL SEPARATOR
Each circuit has a high efficiency, augmented gas im-
pingement type oil separator to maximize oil extrac-
tion without fragile media to break down.
The oil separator, 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 drains back into the compressor through a re-
placeable 0.5-3.0 micron oil filter, and oil supply sole-
noid, is at high pressure. This high pressure “oil injec-
tion” forces the oil into the compressor where it is grav-
ity fed to the rotors and bearings for lubrication.
After lubricating the rotor and bearings, it is injected
through orifices on a closed thread near the suction end
of the rotors. The oil is automatically injected because
of the pressure difference between the discharge 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 re-
frigerant compression (volumetric efficiency).
The oil also provides cooling by transferring much of
the heat of compression from the gas to the oil keeping
discharge temperatures down and reducing the chance
for oil breakdown.
Oil injected into the rotor cage flows into the rotors at
a point about 1.2 x suction. This assures that a required
minimum differential of at least 26 psi (1.8 bar) exists
between discharge and 1.2 x suction, to force oil into
rotor case, a minimum of 9 psi (0.6 bar) is all that is
required to assure protection of the compressor. Oil
pressure is measured as the difference between dis-
charge pressure and the pressure of the oil entering the
rotor case.
Maximum working pressure of the oil separator is 31
bar (450 psi). The oil level should be above the mid-
point of the “lower” oil sight glass when the compres-
sor is running. The oil level should never be above the
top of the “upper” sight glass.
Oil temperature control is provided through liquid injec-
tion activated by the microprocessor, utilizing a tem-
perature sensor, and a solenoid valve.
OIL COOLER
Compressor oil cooling is provided by refrigerant liq-
uid, which is injected into the rotor suction when the
temperature setpoint has been exceeded.
REFRIGERANT CIRCUITS
Each refrigerant circuit uses copper refrigerant pipe
formed on computer controlled bending machines to
reduce the number of brazed joints resulting in a reli-
able and leak resistant system.
Liquid line components include: a manual shut-off
valve with charging port, a high absorption removable
core filter-drier, a solenoid valve, a sight glass with
moisture indicator, and a thermostatic expansion valve.
Suction lines are covered with closed-cell insulation.
CONDENSER
The condenser can be either a field supplied YORK
VCB/Remote Air-cooled condenser or an evaporative
condenser.
COOLER
The 4 pass dual circuit shell and tube type direct expan-
sion (DX) evaporator has chilled liquid circulating across
the tubes from one end to the other. The design working
pressures of the cooler are 150 psi (10 bar) on the wa-
terside (shell) and 300 psi (20 bar) on the refrigerant side
(tubes) which is protected by pressure relief valve(s).
The water baffles are fabricated from galvanized steel
to resist corrosion. Removable heads are provided for
access to internally enhanced, seamless, copper tubes.
Water vent and drain connections are included. The
cooler is insulated with flexible closed-cell foam.
The water nozzles are provided with grooves for
victualic couplings and should be insulated by the con-
tractor after pipe installation.
2

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FORM 201.25-NM1 (302)
POWER AND CONTROL PANELS
All controls and motor starting equipment are factory
wired and function tested. The panel enclosures are
designed to NEMA 1(IP33) and are manufactured from
powder painted galvanized steel.
The panel is divided into power sections for each elec-
trical system, a control section and a common input
section. Each section has separate hinged, latched, and
gasket sealed doors.
Each power section contains:
Compressor starting contactors, control circuit serving
compressor, compressor contactor coils and compres-
sor 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 input current, high input current,
unbalanced current, single phasing, phase reversal, and
compressor locked rotor.
The control section contains:
On/Off toggle switch, microcomputer keypad and dis-
play, microprocessor board (ARB), I/O expansion board
(AIOB), power supply board (APB) and customer ter-
minal block (-XTB1).
MICROPROCESSOR CONTROLS
The microprocessor has the following functions and
displays:
A liquid crystal 40 character display with text provided
on two lines and light emitting diode backlighting for
outdoor viewing.
A color coded, 35 button, sealed keypad with sections
for Display, Entry, Setpoints, Clock, Print, Program and
the unit Auto/Off switch.
The standard functions include: water or glycol cool-
ing, automatic pump down, demand load limiting from
external building automation system input, remote re-
set liquid temperature reset input, unit alarm and sta-
tus contacts, chilled liquid pump control, automatic re-
set after power failure, automatic system optimization
to match operating conditions.
The software is stored in non-volatile memory
(EPROM) to eliminate unit failure due to AC power
failure. The programmed setpoint is stored in a 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.
If the motor current exceeds the 115% FLA trip point
after 3 seconds of operation on Star/Delta starter, the
microprocessor 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 carried out before restart-
ing a system that has faulted on high motor current.
The microprocessor also provides low motor current
protection when it senses a motor current less than
10% FLA. Low motor current protection is activated 4
seconds after start on Star/Delta to allow the motor to
start. The microprocessor will shut the system down
whenever low motor current is sensed and will lock
out a system if three faults occur in 90 minutes. Once a
system is locked out on Low Motor Current, it must be
manually reset with the system switch.
The microprocessor also senses low motor current
whenever a High Pressure Cutout (HPCO) or Motor
Protector (MP) contact opens. The MP and HPCO con-
tacts are connected in series with the motor contactor.
Whenever either of these devices are open, the contactor
de-energizes and the motor shuts down. Since the mi-
croprocessor is sending a run signal to the contactor, it
senses the low motor current below 10% FLA and shuts
the system down.
Motor Protector Module
The mechanical motor protector module provides ther-
mal and current motor overload protection. This mod-
ule protects against phase to phase current imbalance,
over current, under current, and phase rotation. The
Product Description

FORM 201.25-NM1 (302)
13
YORK INTERNATIONAL
module, mounted in the power panel, utilizes a 7 seg-
ment display which provides operating status and fault
diagnostic information. The 7 segment display will dis-
play either a stationary or a flashing alphanumeric value
which can be decoded by the operator:
Whenever a motor protector trips, the motor protector
contacts wired in series with the motor contacts, open
and the motor contactor de-energizes allowing the mo-
tor to stop. The microprocessor senses the low motor
current and shuts the system down. The microproces-
sor will try two more starts before locking the system
out. The system locks out because the motor protector
is a manual reset device. After the first start the protec-
tor contacts will be open, thus preventing the motor
contactors from energizing. Power must be removed
and re-applied to reset the module.
Current Overload
The protector module uses integral current transform-
ers per phase to provide protection against rapid cur-
rent overload conditions. The module responds to
changes in current and must be set-up using the DIP
switches located on the module (refer to Section 5 for
details). Integral trip curves allow for in-rush currents
during Star/Delta starting without nuisance tripping.
Thermal Overload
Three PTC (positive temperature coefficient) ther-
mistors in the motor windings of each phase provide
thermal protection. The sensor resistance stays rela-
tively constant at 1 kW until 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 13 kW, the mod-
ule trips, which ultimately de-energizes the motor’s
pilot circuit. Reset is manual after the motor cools and
the sensor resistance drops to 3.25 kW.
Current Unbalance (Loaded & Unloaded)
Loss of Phase
A 2 second delay at start-up allows for any unbalances
resulting during normal starting conditions. After this
initial delay, the protector module compares the “Op-
erating Current” to the measured half line current. The
“Operating Current” is given by 0.65 x factory over-
load current setting.
An unloaded compressor condition occurs when any
measured half line current is less than the “Operating
Current.” A current unbalance 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 unbalance exceeding a
loaded level of 17% will result in the motor pilot cir-
cuit being de-energized.
Improper Phase Sequence
The protector module calculates the phase sequence at
start-up using the three current transducers to deter-
mine whether the three phase sequence on the load side
of the main contactor is miswired. Upon detection of a
miswired motor load, the module will de-energize the
main contactor pilot circuit within 50 millisecond re-
sponse time.
KEYPAD CONTROLS
For a detailed description of the keypad controls refer
to the Microprocessor Based Control System Operat-
ing Section 7.
Status Key
This key provides a display of the current operational
and/or fault status of the unit or the individual refriger-
0 NORMAL - NO FAULT DETECTED
FLASHING “0” MOTOR OFF OR UNLOADED < 5A 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 = 13 KOHM RESET =
3.25 KOHM
6 COMMUNICATION ERROR
E OUT OF RANGE OF RLA CALIBRATION
OTHER DEFECTIVE MODULE OR SUPPLY
SYMBOLS VOLTAGE
TABLE 1 – MOTOR PROTECTOR FAULTS
2

YORK INTERNATIONAL
14
FORM 201.25-NM1 (302)
ant systems. The display will show the ‘highest prior-
ity’ information as determined by the microprocessor.
The main categories of messages are: General Status
Messages; Unit Warnings; Anticipation Control Status
Messages; Chiller Fault Status Messages; System Fault
Status Messages.
Display Keys
Each key provides a real-time display of commonly re-
quired information about the chiller and individual re-
frigerant system operating conditions and settings. This
is particularly useful during commissioning, monitor-
ing the operation of the chiller, diagnosing potential
future problems and service troubleshooting. Param-
eters may be displayed in Imperial (°F and PSIG) or
Metric (°C and bar) units.
Print Keys
These keys allow control panel display or remote print-
out of both current real-time operating and programmed
data as well as fault history data from the most recent
six safety shutdowns.
Entry Keys
The numeric and associated keys are used for enter-
ing data required for programming the chiller. The
‘ENTER’ and ‘’ ‘’ keys are also used for scroll-
ing through information available after pressing other
keys.
Setpoints Keys
These keys are used for display and programming of
the local and remote offset chilled liquid temperature
setpoints.
Clock Keys
These keys are used for display and programming of
the clock and operating schedule for the chiller.
Program Key
This key is used for display and programming of the
chiller operational settings and limits.
ACCESSORIES AND OPTIONS:
Alternative Refrigerants
Contact your nearest YORK office for information and
availability on alternative HFC refrigerants.
ELECTRICAL OPTIONS:
MULTIPLE POINT POWER SUPPLY CONNEC-
TION – Standard field power wiring connection on
all models is Multiple Point Power Connection to fac-
tory-provided Terminal Blocks. Two field-supplied elec-
trical power circuits with appropriate branch circuit pro-
tection provide power to each of two motor control cen-
ter cabinets, located on either side of the Control panel
on the front of the chiller. Each cabinet contains starter
elements for one compressor.
Optional to the Terminal Blocks for field power con-
nection are Non-Fused Disconnects or Circuit Breaker
Switches with external, lockable handles.
SINGLE-POINT POWER CONNECTION – (Fac-
tory-mounted) An optional configuration for field con-
nection of a single electrical circuit to: either Terminal
Block or Non-Fused Disconnect Switch with lockable
external handle (in compliance with Article 440 of
N.E.C., to isolate unit power supply for service). Fac-
tory wiring is provided from the Terminal Block or Dis-
connect Switch to Factory supplied individual system
Circuit Breakers, Non-Fused Disconnect switch with
external, lockable handle or J Class Fuses/Fuse Block
in each of the two compressor motor control centers.
(Note: Single-Point Non-Fused Disconnect Switch will
not be supplied with individual system Non Fused Dis-
connect Switches with external, lockable handles in each
of the two compressor motor control centers).
65 Ka HIGH VOLTAGE PROTECTION – Non-
Fused Disconnect Switch with fuses (200 & 575V) or
Circuit Breakers (230, 380, & 460V) are used for ap-
plications where customers have a requirement for
Single-Point wiring with high “fault current” withstand-
ing capability. This option provides between 50Ka and
65Ka withstand protection to the equipment.
BUILDING AUTOMATION SYSTEM INTER-
FACE (Factory-mounted) – Provides means to reset
the leaving chilled liquid temperature or percent full
load amps (current limiting) from the BAS (Factory-
mounted):
• Printed circuit board to accept 4 to 20 milliamp, 0 to
10VDC, or dry contact closure input from the BAS.
• A YORK ISN Building Automation System can
provide a Pulse Width Modulated (PWM) signal
direct to the standard control panel via the stan-
dard onboard RS485 port.
Product Description

FORM 201.25-NM1 (302)
15
YORK INTERNATIONAL
FLOW SWITCH – The flow switch or its equivalent
must be furnished with each unit. 150 PSIG (10.5 bar)
DWP – For standard units. Johnson Controls model
F61MG-1C Vapor-proof SPDT, NEMA 4X switch (150
PSIG [10.5 bar] DWP), -20°F to 250°F- (29°C to
121°C), with 1" NPT connection for upright mounting
in horizontal pipe. (Field-mounted)
DIFFERENTIAL PRESSURE SWITCH –Alterna-
tive to the above mentioned Flow Switch. Pretemco
Model DPS 300A-P4OPF-82582-S (20.7bar max work-
ing pressure). SPDT 5 amp 125/250VAC switch. Range:
0 - 2.8 bar, deadband: 0.003 - 0.005bar, with 1/4 NPTE
pressure connections.
LANGUAGE LCD AND KEYPAD – Standard dis-
play language and keypad is in English. Spanish is avail-
able as an option.
PRINTER KIT – Printer for obtaining printout of unit
operating and history data. (Field-mounted)
MULTIPLE UNIT SEQUENCE CONTROL (Field-
mounted) – Sequencing Control with automatic unit
sequencing. Necessary items for operation and control
of up to eight units with parallel water circuits. Includes
software and mixed liquid temperature sensor (inter-
connecting wiring by others).
PRESSURE VESSEL CODES – Coolers and con-
densers can be supplied in conformance with the fol-
lowing pressure codes:
A.S.M.E. (Standard)
CHICAGO CODE RELIEF VALVES (Factory-
mounted) – Unit will be provided with relief valves to
meet Chicago Code requirements.
ACCESSORIES:
FLANGES (Weld Type) – Consists of 150 PSI (10.5
bar ) standard cooler (150 lb) R.F. flanges to convert to
flanged cooler-connections and includes companion
flanges. (Field-mounted)
FLANGES (Victaulic Type) – Consists of (2)
Flange adapter for grooved end pipe (standard 150
PSI [10.5 bar] cooler). Includes companion flanges.
(Field-mounted)
FINAL PAINT – The unit can be painted with an op-
tional coat of Caribbean Blue overspray paint. (Factory)
VIBRATION ISOLATION:
•Neoprene Isolators – Recommended for normal
installations. Provides very good performance in most
applications for the least cost. (Field- mounted)
•1" Spring Isolators – Level adjustable, spring and
cage type isolators for mounting under the unit base
rails. 1" nominal deflection may vary slightly by
application. (Field-mounted)
•2" Seismic Spring Isolators – Restrained Spring-
Flex Mountings incorporate a rugged welded steel
housing with vertical and horizontal limit stops.
Housings designed to withstand a minimum 1.0g
accelerated force in all directions to 2". Level ad-
justable, deflection may vary slightly by applica-
tion. (Field-mounted)
ALTERNATIVE CHILLED FLUID APPLICATIONS:
Standard water chilling application range is 40°F to
50°F (4.4°C to 10°C) Leaving Chilled Water Tempera-
ture. To protect against nuisance safety trips below 40°F
(4.4°C) and reduce the possibility of cooler damage due
to freezing during chiller operation, the unit micropro-
cessor automatically unloads the compressors at ab-
normally low suction temperature (pressure) conditions,
prior to safety shutdown.
•Process Brine Option – Process or other applica-
tions requiring chilled fluid below 40°F (4.4°C) risk
water freezing in the evaporator, typically overcome
by using antifreeze. For these applications, the chiller
system incorporates brine (ethylene or propylene
glycol solution), and the system design Leaving
Chilled Fluid Temperature must be provided on the
order form to ensure proper factory configuration.
•Thermal Storage Option – Thermal Storage re-
quires special capabilities from a chiller, including
the ability to ‘charge’ an ice storage tank, then pos-
sibly automatically reset for operation at elevated
Leaving Chilled Fluid Temperatures as required by
automatic building controls. The Thermal Storage
Option provides Ice Storage duty Leaving Chilled
Fluid setpoints from 25°F to 15°F ( -4°C to -10°C)
minimum during charge cycle, with a Reset range
of 36°F (20°C) supply fluid temperature.
2

YORK INTERNATIONAL
16
FORM 201.25-NM1 (302)
NOMENCLATURE
Low pressure liquid refrigerant enters the cooler tubes
and is evaporated and superheated by the heat energy
absorbed from the chilled liquid passing through the cooler
shell. Low pressure vapor enters the compressor where
pressure and superheat are increased. High pressure va-
por is passed through the oil separator where compressor
oil is removed and recirculated to the compressor. High
pressure superheated refrigerant enters the condenser shell
where heat is rejected to the condenser water passing
through the tubes. The fully condensed and subcooled liq-
uid leaves the condenser and enters the expansion valve,
where pressure reduction and further cooling takes place.
The low pressure liquid refrigerant then returns to the cooler.
Each refrigerant circuit utilizes a refrigerant to refrigerant
suction line heat exchanger to maximize chiller capacity
and efficiency by subcooling liquid refrigerant delivered to
the expansion valve and superheating suction gas deliv-
ered to the compressor.
FIG. 3 – FLOW DIAGRAM
Product Description
YCRS0140SC46YAA
:Design Series F
:Engineering
Change
or PIN Level
: YORK
: Chiller
: Remote
: Condenser
kW Standard Unit
: 0100: 0120: 0140
: 0180: 0200: 0220
: 0240
:R-22
:Wye-Delta
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
BASE PRODUCT TYPE NOMINAL CAPACITY UNIT DESIGNATOR REFRIGERANT VOLTAGE/STARTER DESIGN / DEVELOPMENT LEVEL
Y #### S C 1 7 A
C28Y A
R40
S46
58
High Pressure Superheated Vapou
r
High PressureSubcooledLiquid
Low Pressure Liquid
Oil Low Pressure Superheated Vapour
SV = Solenoid Valve SG = Sight Glass TEV = Thermostatic Expansion Valve
Refrigerant Circuit No 2
SV
Oil
Separators
SG
Compressor
Cooler
Oil Cooling
Liquid Injection
TEV
SG
Relief
Valve
Customer Option
Customer supplied
optional relief
valve
FUNCTIONAL DESCRIPTION
LD07755

FORM 201.25-NM1 (302)
17
YORK INTERNATIONAL
DELIVERY AND STORAGE
To ensure consistent quality and maximum reliability,
all units are tested and inspected before leaving the fac-
tory. Units are shipped completely assembled and con-
taining refrigerant under pressure. Units are shipped
without export crating unless this has been specified
on the Sales Order.
If the unit is to be put into storage, before installation,
the following precautions should be observed:
Ensure that all openings, such as water connections,
are securely capped.
Do not store where exposed to ambient air tempera-
tures exceeding 107°F (42°C).
The unit should be stored in a location where there is
minimal activity to limit the risk of accidental physical
damage.
To prevent inadvertent operation of the pressure relief
devices the unit must not be steam cleaned.
It is recommended that the unit is periodically inspected
during storage.
INSPECTION
Remove any transit packing and inspect the unit to en-
sure that all components have been delivered and that
no damage has occurred during transit. If any damage
is evident, it should be noted on the shipment docu-
mentation and a claim entered according to the instruc-
tions given.
Major damage must be reported immediately to your
local YORK representative.
MOVING THE UNIT
Before moving the unit, ensure that the installation site
is suitable for installing the unit and is capable of sup-
porting the weight of the unit and all associated services.
The units are designed to be lifted using either lifting
chains or a fork lift.
Lifting by Crane / Hoist
A spreader frame should be used to prevent damage to
the unit from the lifting chains.
The unit must only be lifted at the
points provided.
SECTION 3
TRANSPORTATION, HANDLING AND STORAGE
FIG. 4 – LIFTING INFORMATION
3
RIGGING INSTRUCTIONS
AND ESTIMATED SHIPPING
WEIGHT LBS.
MODEL WEIGHT
YCRS0100SC 5,989
YCRS0120SC 6,271
YCRS0140SC 6,584
YCRS0180SC 9,026
YCRS0200SC 9,132
YCRS0220SC 9,162
YCRS0240SC 9,252
LD07801

YORK INTERNATIONAL
18
FORM 201.25-NM1 (302)
Lifting by Fork Lift
Insert the forks into the lifting slots in the shipping skid.
The forks must pass through the lifting slots on both
sides of the unit to prevent damage.
CONTROL PANEL REMOVAL
For installation in locations where access width is lim-
ited, the control panel may be removed as shown in the
figure below.
FIG. 5 – CONTROL PANEL REMOVAL
LIFTING WEIGHTS
For details of weights and weight distribution refer to
Section 9.
Transportation, Handling and Storage
LD06595

FORM 201.25-NM1 (302)
19
YORK INTERNATIONAL
LOCATION REQUIREMENTS
To achieve optimum performance and trouble-free ser-
vice, it is essential that the proposed installation site
meets with the location and space requirements for the
model being installed. For dimensions, weight and space
requirements, including service access details, refer to
Section 9.
The clearances recommended are nomi-
nal for the safe operation and mainte-
nance of the unit and power and con-
trol panels. Local health and safety regu-
lations, or practical considerations for
service replacement of large compo-
nents, may require larger clearances
than those given in Section 9.
Units are designed for indoor installation and not in-
tended for wet, corrosive or explosive atmospheres.
Installation should allow for water drain, ventilation
and sufficient clearance for service, including tube
cleaning/removal.
For installation in equipment rooms near noise-critical
areas, common walls should be of adequate sound at-
tenuating construction, all doors should be tightly
gasketed, and the unit should have vibration isolators
fitted.
The unit must be installed on a suitable flat and level
concrete base (2) that extends to fully support the unit
base frame.
On basement foundations remove a portion of the base-
ment floor (3) so that a concrete base can be poured
resting on the ground (1) , with a corkboard (4) installed
on both sides, and a waterproof sealing compound (5).
The concrete base must capable of supporting 150% of
the operating weight. In case of upper floors, the unit
and piping should be isolated from walls and ceiling.
The unit may be bolted to the foundation using 1/2"
(13 mm) Ø holes in the base of the framework. When
lower transmitted vibration levels are required optional
anti-vibration isolators can be supplied loose for site
installation.
INSTALLATION OF VIBRATION ISOLATORS
An optional set of vibration isolators can be supplied
loose with each unit (refer to Section 9 for details).
PIPEWORK CONNECTION
General Requirements
The following piping recommendations are intended
to ensure satisfactory operation of the unit. Failure to
follow these recommendations could cause damage to
the unit, or loss of performance, and may invalidate
the warranty.
The maximum flow rate and pressure
drop for the cooler and condenser
must not be exceeded at any time. Re-
fer to Section 9 for details.
• The water must enter the heat exchanger(s) by the
inlet connection. Refer to Section 9 for details.
• A flow switch or differential switch must be installed
in the customer pipework at the outlet of the ex-
changers as shown in the arrangement diagrams, and
wired back to the control panel using screened cable.
For details refer to “Electrical Connection”. This is
to prevent damage to the exchanges caused inad-
equate liquid flow.
The flow switch used must have gold
plated contacts for low voltage/current
operation. Paddle type flow switches
suitable for 150 PSIG (10 bar g) work-
ing pressure and having a 1" N.P.T.
connection can be obtained from
YORK as an option for the unit.
• The liquid pump(s) installed in the pipework
system(s) should discharge directly into the unit
heat exchanger section of the system. The pump(s)
require an auto-starter (by others) to be wired to
the control panel. For details refer to “Electrical
Connection”.
SECTION 4
INSTALLATION
4

YORK INTERNATIONAL
20
FORM 201.25-NM1 (302)
• Pipework and fittings must be separately supported
to prevent any loading on the heat exchanger(s).
Flexible connections are recommended which will
also minimize transmission of vibrations to the
building. Flexible connections must be used if the
unit is mounted on anti-vibration mounts as some
movement of the unit can be expected in normal
operation.
• Pipework and fittings immediately next to the heat
exchangers should be readily de-mountable to en-
able cleaning prior to operation, and to facilitate
visual inspection of the exchanger nozzles.
• Each heat exchanger must be protected by a
strainer, preferably of 40 mesh, fitted as close as
possible to the liquid inlet connection, and provided
with a means of local isolation.
• The heat exchanger(s) must not be exposed to flush-
ing velocities or debris released during flushing. It
is recommended that a suitably sized bypass and
valve arrangement is installed to allow flushing of
the pipework system. The bypass can be used dur-
ing maintenance to isolate the heat exchanger with-
out disrupting flow to other units.
• Thermometer and pressure gauge connections
should be provided on the inlet and outlet connec-
tions of each heat exchanger.
• Drain and air vent connections should be provided
at all low and high points in the pipework to per-
mit drainage of the system, and to vent any air in
the pipes.
• Liquid systems at risk of freezing, due to low am-
bient temperatures, should be protected using in-
sulation and heater tape and/or a suitable glycol
solution. The liquid pump(s) must also be used to
ensure liquid is circulated when the ambient tem-
perature approaches freezing point. Insulation
should also be installed around the heat exchanger
nozzles.
Heater tape of 21 watts per meter un-
der the insulation is recommended,
supplied independently and controlled
by an ambient temperature thermostat
set to switch on at 37°F (3°C) above
the freezing temperature of the liquid.
Any debris left in the water pipework
between the strainer and heat ex-
changer could cause serious damage
to the tubes in the heat exchanger and
must be avoided. The installer/user
must also ensure that the quality of
the water in circulation is adequate,
without any dissolved gasses which
can cause oxidation of steel parts
within the heat exchanger(s).
WATER TREATMENT
The unit performance given in the Design Guide is
based on a fouling factor of 0.00025 ft²hr °F/Btu (0.044
m² °C/kW). Dirt, scale, grease and certain types of water
treatment will adversely affect the heat exchanger sur-
faces and therefore unit performance. Foreign matter
in the water system(s) can increase the heat exchanger
pressure drop, reducing the flow rate and causing po-
tential damage to the heat exchanger tubes.
Aerated, brackish or salt water is not recommended for
use in the water system(s). YORK recommends that a
water treatment specialist is consulted to determine that
the proposed water composition will not affect the
evaporator materials of carbon steel and copper. The
pH value of the water flowing through the heat exchang-
ers must be kept between 7 and 8.5.
Glycol Solutions
For unit operation with chilled liquid temperatures leav-
ing the cooler at below 40°F (4.4°C), glycol solutions
should be used to help prevent freezing. Section 9, gives
recommended solution strength with water, as a per-
centage by weight, for the most common types of gly-
col. It is important to check glycol concentration regu-
larly to ensure adequate concentration and avoid pos-
sible freeze-up in the cooler.
When using glycol solutions, pressure
drops are higher than with water. Spe-
cial care must be taken not to exceed
the maximum pressure drop allowed.
Installation