York W1LC420 User manual

GENERAL
YORK’s W1LC Packaged Air-Cooled Liquid Chillers provide
chilled liquid for all air conditioning applications. They are
competely self contained chilling systemsutilizing an accessi-
ble hermetic compressor, liquid cooler, air cooled condenser
coils and electrical control panel all mounted on a steel base.
They are factory piped, wired, dehydrated, evacuated, leak
tested, pressure tested, functionally tested and fully charged
with Refrigerant-22.
All controls are located in the front of the unit and are readily
accessible for maintenance, adjustment and service. All wiring
(power and control) can be made through the bottom of the
compressor compartment.
REFERENCE
Additionalinformationonthedesign,installation,operationand
service of air conditioning equipment is available in the follow-
ing reference forms.
•55.70-N1 - General Installation
•55.70-N2 - Pre-start & Post-start Check List
•55.70-N3 - General Service Information
•55.05-NM - Evacuation and Charging
Renewal Parts:
•Refer to Parts Manual for complete listing of replacement
parts on this equipment.
The above forms and all other forms referenced in thisinstruc-
tion may be ordered from:
Publications Distribution Center
Unitary Products Group
P.O. Box 1592, York, Pa. 17405
INSPECTION
As soon as a unit is received, it should be inspected for possible
damage during transit. If damage is evident, the extent of the
damage should be noted on the carrier’s freight bill. A separate
request for inspection by the carrier’s agent should be made in
writing. See Form 50.15-NM for additional information.
LIQUID CHILLER
(AIR COOLED)
INSTALLATION INSTRUCTION Supersedes: 570.05-N2Y (494)
570.05-N4Y (495)
Installer should pay particular attention to the words: NOTE, CAUTION and WARNING . Notes are intended to clarify or make
theinstallation easier. Cautions are given to prevent equipment damage.Warnings are givento alert installerthat personal injury
and/or equipment damage may result if installation procedure is not handled properly.
MODELS W1LC420 AND 530
STYLE B
035-13054
®
Only -25 and -46
voltage codes
CAUTION
THIS PRODUCT MUSTBE INSTALLED IN STRICTCOMPLIANCE
WITHTHEENCLOSEDINSTALLATIONINSTRUCTIONSANDANY
APPLICABLE LOCAL, STATE, AND NATIONAL CODES
INCLUDING, BUT NOT LIMITED TO, BUILDING, ELECTRICAL,
WARNING
INCORRECT INSTALLATION MAY CREATE A CONDITION
WHERE THE OPERATION OF THE PRODUCT COULD CAUSE
PERSONAL INJURY OR PROPERTY DAMAGE

General ................................................................................ 1
Inspection............................................................................. 1
Reference ............................................................................1
Approvals............................................................................. 1
Nomenclature....................................................................... 2
INSTALLATION
Limitations............................................................................ 3
Handling............................................................................... 3
Location ...............................................................................3
Clearances........................................................................... 4
Compressor Hold-Down Nuts.............................................. 4
Discharge Line Hold-Down Bracket..................................... 4
Chilled Liquid Piping............................................................4
Electrical Wiring................................................................... 5
Power Wiring................................................................ 5
Control Wiring............................................................... 5
Multiple Units................................................................5
Wiring To External Water Line Heaters ........................ 5
OPERATION
Checking Prior To Initial Start Up......................................... 8
Applying Power To The Unit................................................. 8
Sequence of Operation........................................................ 8
Compressor No. 1 Operation...............................................8
Part-Winding Start........................................................ 9
Pumpdown.................................................................... 9
Anti-Short Cycling......................................................... 9
Oil Failure .....................................................................9
High / Low Pressure Lockout ....................................... 9
Compressor No. 2 Operation...............................................9
Part-Winding Start........................................................ 9
Pumpdown.................................................................... 9
Anti-Short Cycling......................................................... 9
Oil Failure .....................................................................9
High / Low Pressure Lockout ....................................... 9
Water Cooler Freeze Prevention....................................... 10
Compressor Motor Protection System .............................. 10
Condenser Fan Motor Control........................................... 10
Electric Controls..................................................................11
MAINTENANCE
General.............................................................................. 12
Cleaning Condenser Surface ............................................ 12
Lubricating Fan Motors...................................................... 12
Compressor Replacement................................................. 12
Secure Owner’s Approval.................................................. 12
TABLES
No. Description Page
1 Application Data.......................................... 3
2 Physical Data.............................................. 4
3 Electrical Data............................................. 6
4 Electrical Data (International Models) ........ 6
5 Water Side Pressure Drop.......................... 6
FIGURES
No. Description Page
1 Unit Handling .............................................. 3
2 Support Beam Locations............................ 4
3 Compressor Hold-Down Nuts..................... 4
4 Field Wiring Diagram.................................. 5
5 Unit Dimensions and Clearances............... 7
6 Condenser Fans Orientation ...................... 10
W 1 L C
2
5
2 A
PRODUCT NOMENCLATURE
PRODUCT GENERATION
1 = New or Current
PRODUCT CATEGORY
W = Air-Cooled Chiller
PRODUCT IDENTIFIER
LC = Liquid Chiller
VOLTAGE CODE
25 = 208/230-3-60
40 = 380-3-60
46 = 460-3-60
50 = 380/415-3-50
NOMINAL COOLING
CAPACITY
420 = 429 MBH (35.8 Tons)
530 = 538 MBH (44.8 Tons)
FACTORY INSTALLED HEAT
A= Not Applicable
(Cooling only)
4 0
TABLE OF CONTENTS
570.05-N4Y
2Unitary Products Group

LIMITATIONS
These units must be installed in accordance with all national
andlocalsafetycodes.Ifnolocalcodesapply,installationmust
conform with the appropriate national codes. See Table 1 for
Application Data. Units with voltage codes 25 and 46 are
certified by the Electrical Testing Laboratory (ETL) as meeting
the requirements of the ANSI/UL465 Central Cooling Air Con-
ditioner Standard. If components are to be added to a unit to
meet local codes, theyare to be installed at the dealer’s and/or
the customer’s expense.
HANDLING
These chillersare shipped ascompletelyassembledunits with
a full operating charge. Care should be taken to avoid damage
due to rough handling.
CAUTION: Units are not designed for stacking.
A unit should be lifted by inserting hooks through the holes in
the base rails.
CAUTION: Spreader bars of greater width than the unit must
be used to avoid crushing the unit frame or panels
with lifting chains or cables.
When preparing to move the unit, always determine the center
of gravity in order to equally distribute the weight. Slings
connected to the compressor end of the unit will usually have
to bemade shorter thanthose to therear ofthe unit, so theunit
will lift evenly. Refer to Figure 1.
LOCATION
These units are designed for outdoor installations on ground
or rooftop. The location should be selected for minimum sun
exposure and to insure an adequate supply of fresh air for the
condenser.Avoidlocationsbeneathwindowsorbetweenstruc-
tures where normal operating sounds may be objectionable.
The condenser fans are propeller typeand are not suitable nor
intended for use with duct work in the condenser air stream.
On either rooftop or ground level installations, rubber padding
canbeappliedbetweenthebaserailsoftheunitanditssupport
to lessen the transmission of vibration.
GROUND LEVEL LOCATIONS
It is important that the units be installed on a substantial base
that will not settle. See Table 2 for unit weights. Setting could
cause strain on the refrigerant or water lines resulting in leaks.
A one-piece concrete slab with footers that extend below the
frost line is recommended.
INSTALLATION
Unit
Power Supply Voltage Variations
Min. Volts Max. Volts
208/230-3-60 187 253
460-3-60 414 506
380/415-3-60 342 440
380-3-60 355 415
TABLE 1 - APPLICATION DATA
FIG. 1 - UNIT HANDLING
Model Dimensions (Inches))
DEXY
W1LC420 118-5/8 86-7/8 43 46
W1LC530 118-5/8 86-7/8 41 46
Limitations Model
W1LC420 W1LC530
Cooler Liquid
(GPM) Min. 55 70
Max. 150 160
Leaving Liquid
Temp. (°F) Min.132 32
Max. 50 50
Air Entering
Condenser (°F) Min.220 20
Max. 115 115
1For applications below 40°F leaving liquid temperature, a mixture of ethylene glycol and
water must be used.
2Water in the cooler is protected from freeze-up to 0°F ambient by a heater under the
insulation.
570.05-N4Y
Unitary Products Group 3

Additionally, the slab should NOT be tied to the main building
foundationsas noise due to vibration may be transmitted.
For ground level installations, precautions should be taken to
protecttheunitfromtamperingandunauthorizedpersonsfrom
injury. Screwson access panels will prevent casual tampering.
Further safety precautions such as a fenced enclosure or
locking devices on the panels may be advisable. Check local
authorities for safety regulations.
ROOFTOP LOCATIONS
Choose a spot with adequate structural strength to safely
support the entire weight of the unit and service personnel.
Care must be taken so as not to damage the roof. Consult the
building contractor or architect if the roof is bonded. The unit
must be mounted level on a minimum of two beams. The
beamsshould(1)bepositionedperpendiculartotheroofjoists,
(2) extend beyond the dimensions of the section to distribute
the load onthe roof, (3) be capable of supporting the weight of
the unit and (4) be positioned parallel to the longer base rails
of the unit OR parallel to the shorter base rails of the unit as
shown in Figure 2.
CLEARANCES
The units must be installed with sufficient clearance for air to
enter the condenser coil and not be recirculated after dis-
charge. Sufficient clearance must also be provided for service
access. Refer to the unit illustration in Figure 5 for minimum
clearances.
Theareawithintheclearancesandtheareaundertheunitmust
be kept clear of all obstructions thatwould impede free air flow
to the unit. In installations where low ambient operation is
intended and snow accumulation is expected, additional unit
height must be provided to insure full air flow.
COMPRESSOR HOLD-DOWN NUTS
For shipping, the compressor hold-down nuts are tightened,
drawing the compressor mounting feet down to the shipping
stops.
CAUTION: After the unit is in its final position, remove the
compressor hold-down nuts and shipping spac-
ers. Install rubber grommets (shipped in bagtied
tocompressor).Replacethehold-down nutsand
tighten until they start to bind the rubber grom-
mets. Continue to tightened additional half turn.
See Figure 3.
DISCHARGE LINE HOLD-DOWN BRACKET
CAUTION: Do NOT remove the discharge line support brack-
ets located within the compressor compartment. It
reduces vibration during unit operation.
CHILLED LIQUID PIPING
Thecoolerinletandoutletliquidconnectionsare3inchnominal
pipe size. The connections are made with grooved ends de-
signed to accept Victaulicgrooved pipe couplings only. Re-
move the shipping caps and discard.
CAUTION: The liquid pipingRETURNING to the chiller MUST
be attached to the cooler connection CLOSEST to
the compressor end of the unit. The liquid piping
LEAVING the cooler MUST be attached to the
cooler connection FURTHEST from the compres-
sor end of the unit. See Figure 5 for liquid inletand
outlet connections.
FIG. 2 - SUPPORT BEAM LOCATIONS
Model Dimensions (Inches)
DEPQR
W1LC420 118-5/8 86-3/4 30 70 76
W1LC530 118-5/8 86-3/4 30 70 76
Model
Compressor1Condenser Unit Weight
(Lbs.) Oper.
Charge,
(R-22)
(Lbs.)
Cap.
Reduction
(%)
Fan (Propeller) Fan
Motors3Coil (Copper Tube - Aluminum Fin)
Nom.
Cap.
(Tons)
No.
of
Cyl.
Stages
of
Cap. Qty.2Dia.
(In.) Pitch (Deg.) Nom. CFM HP RPM Face
Area
(Ft.2)Rows
Deep Rows Wide Tube
OD
(in.)
Fins
per
inch Ship. Oper.
W1LC420
System 1
System 2 20 20 4 42 23 324 30 16,050 16,050 3/4 1075 30.0 30.0 3 336 36 3/8 12 3,380 3,480 26.0 26.0 25,50 75,100
W1LC530
System 1
System 2 20 30 4 62 23 424 30 14,400 19,400 3/4 1075 35.0 35.0 4 430 42 3/8 12 3,720 3,820 26.0 35.0 20,40 60,100
1All compressors are semi-hermetic.
2During low ambient conditions, the motor for one of these fans will operate at 450 RPM.
3These PSC motors are directly connected to the condenser fans and have inherent protection, ball bearings and a 48 frame. Their rotation is clockwise when viewing the shaft endof
the motor.
TABLE 2 - PHYSICAL DATA
FIG. 3 - COMPRESSOR HOLD-DOWN NUTS
570.05-N4Y
4Unitary Products Group

The chilled liquid lines that are exposed to outdoor ambient
should be wrapped with supplemental heater cable and insu-
lated to protect against freeze-up during low ambient periods
and to prevent formation of condensation on lines in warm
humid climates. The unit provides electrical contact closure
whentheoutdoorambientislowandcoolerwaterisnotflowing
to energize these supplemental heaters but power must be
supplied from a separate power source. Refer to Figure 4.
Awater flow switch is installed on the leavingwater connection
of the cooler. For proper operation, there should be s straight
horizontal run of at least 5 pipe diameters down stream of the
switch.
The chilled liquid piping system must be laid out so that the
circulating pump discharges into the cooler. Hand stop valves
are recommended for use in all lines to facilitate servicing.
Drainconnectionsshouldbeprovidedatalllowpointstopermit
complete drainage of the cooler system and piping. The cooler
barrelisprovidedwitha3/4inchdrainconnectiononthebottom
of the cooler and a 1/4 inch air purge connection on the top of
thecooler. Astrainer(40 mesh)isrecommendedforuseonthe
inlet to the cooler.
NOTE: When filling the piping system with liquid, purging the
system of air is essential for the unit to achieve design
capacity. Be sure to slowly fill the system with liquid
andtoopenallpurgeconnectionsinthesysteminclud-
ing the 1/4 inch connection on top of the cooler. Close
all connections after all air has been purged from the
system.
As an aid to servicing, thermometers and pressure gauges are
recommended in the inlet and outlet water lines. A 1/4 inch
pluggedconnectionisprovidedoneachconnectionforthefield
to install these devices.
ELECTRICAL WIRING
WARNING:Allpowerandcontrolwiringmustbeinaccordance
with national and local electrical codes.
POWER WIRING
These units are designed for single pointpower source. Check
the available power and unit nameplate to see if the voltages
are the same. Run the necessary number of properly sized
wires to the unit. Provide a disconnect switch and fusing as
required. Route the conduit to the large knockout located on
the bottom of the electrical box. Remove the plastic plug from
the knockout and discard. See Table 3 or 4 for electrical data.
The disconnect switch may be bolted to the side of the unit but
not to any of the removable panels; this would interfere with
access to the unit. Make sure that no refrigerant lines or coils
will be punctured when mounting the disconnect switch, and
note that it must be suitable for outdoor installation.
CONTROL WIRING
ll control wiring is connected to the field wiring terminal block,
5 TB, located in the bottom of the control box. Amore detailed
description of operating controls is given in the Operation
Section.
WARNING:Allcontrolwiringis120voltssinglephase.Properly
sized and insulated wiring should be used.
An indoor room thermostat is not required to operate these
units. Each unit contains an automatic temperature control
which maintains a constant return liquid temperature to the
cooler. Several recommended and optional field hookups are
connected to the 3TB terminal strip. They are:
1. Chilled Water Pump Starting Circuit - terminals K and H.
(Recommended, not to be used for normal start.)
2. Day/NightSwitch Contacts forCycling UnitOn andOffwith
Unit Pumpdown - terminals G and C. Remove jumper J1.
(Recommended)
3. Low Leaving Liquid Temperature Alarm - terminals B and
48. (Optional)
4. LossofLiquidFlowAlarm/AuxPumpStart-terminalsAand
48. (Optional)
MULTIPLE UNITS
For increased compressor protection and to reduce power
inrush at start-up on multiple chiller installations, provisions
must be made to preventsimultaneousstart-up of two or more
units. Also, some method may be employed to automatically
cycle on or off one or more of the units to permit more efficient
operation at part load conditions.
WIRING TO EXTERNALWATER LINE HEATERS
When the outdoor ambient drops below 36°F and there is no
water flow, a contact in the unit closes across terminals W and
Lon the 2TB terminal block located in the bottom of the control
box. This contact closure may be used to energize field in-
stalled heaters located on waterlines to the unit. See Figure 4.
WARNING:The unit contact closure does NOT provide power
fortheheaters.Singlephase120or240voltpower
must come from a separate, field installed fused
disconnect. Heater power must not exceed 1200
watts.
FIG. 4 - FIELD WIRING DIAGRAM
570.05-N4Y
Unitary Products Group 5

Model Compressor Condenser Fan Motors Unit Ampacity
(Amps)
Max.
Fuse
Size
(Amps)
Min. Wire
Size,4
(AWG)
Max. Wire
Lg.5
(Ft.)
Power Supply Qty. RLA LRA Power Supply HP Qty. FLA
(each)
W1LC420 A25 208/230-3-60 2 88.5
each 4281 each 208/230-1-60 3/4 4 24.2 4.5 225 250 0000 212 @ 208 227 @ 230
A46 460-3-60 2 44.3
each 214 each 460-1-60 3/4 4 22.3 2.5 114 125 2 374
W1LC530 A25 208/230-3-60 1
188.5 135 4281 5652208/230-1-60 3/4 5 24.2 4.5 288 300 350 226 @ 208 237 @ 230
A46 460-3-60 1
144.3 67.5 214 283 460-1-60 3/4 5 22.3 2.5 146 175 0 424
1250 Amps on part winding start. 4Based on three, 75°C insulated copper conductors in steel conduit.
2340 Amps on part winding start. 5Based on a 3% voltage drop.
TABLE 3 - ELECTRICAL DATA
Model Compressor Condenser Fan Motors Unit Ampacity
(Amps)
Max.
Fuse
Size
(Amps)
Min. Wire
Size,4
(AWG)
Max. Wire
Lg.5
(Ft.)
Power Supply Qty. RLA LRA Power Supply HP Qty. FLA
(each)
W1LC420 A50 380/415-3-50 2 38.0
each 1651 each 380/415-1-50 3/4 4 22.3 2.5 105 110 2 320 @ 380 368 @ 415
A40 380-3-60 2 52.1
each 208 each 460-1-60 3/4 4 22.3 2.5 135 150 0 377
W1LC530 A50 380/415-3-50 1
138.0 62.7 1651 2252380/415-1-50 3/4 5 22.3 2.5 135 150 0 369 @ 380 412 @ 415
A40 380-3-60 1
152.1 77.8 208 307 460-1-60 3/4 5 22.3 2.5 170 200 00 357
1100 Amps on part winding start. 4Based on three, 75°C insulated copper conductors in steel conduit.
2150 Amps on part winding start. 5Based on a 3% voltage drop.
TABLE 4 - ELECTRICAL DATA (International Models)
TABLE 5 - WATER SIDE PRESSURE DROP
W1LC420
GPM PSIG FEET
55 2.6 5.9
60 2.9 6.8
65 3.4 7.8
70 3.9 9.0
75 4.3 10.0
80 4.9 11.3
85 5.4 12.5
90 6.1 14.0
95 6.6 15.3
100 7.4 17.0
105 8.0 18.5
110 8.7 20.0
115 9.3 21.5
120 10.0 23.0
125 10.8 25.0
W1LC530
GPM PSIG FEET
70 2.5 5.7
75 2.8 6.5
80 3.2 7.4
85 3.6 8.3
90 4.0 9.3
95 4.5 10.4
100 5.0 11.5
105 5.5 12.8
110 6.1 14.0
115 6.7 15.4
120 7.2 16.5
125 7.8 18.0
130 8.5 19.5
135 9.1 21.0
140 9.8 22.5
145 10.4 24.0
150 11.1 25.5
155 11.7 27.0
570.05-N4Y
6Unitary Products Group

Alldimensionsare ininches.Theyaresubject
to change without notice. Certified dimen-
sions will be provided upon request.
FIG. 5 - UNITDIMENSIONS AND CLEARANCES
MODEL A B C D E F G
W1LC420 127-1/4 91-1/8 51-5/8 118-5/8 86-7/8 22-1/2 6-1/4
W1LC530 127-1/4 91-1/8 55-5/8 118-5/8 86-7/8 26 6-1/4
BASIC UNIT DIMENSIONS
MODEL COOLER SIZE
(Dia. x Lg.)
WATER
CONNS.*
(Inlet & Outlet) JK LM
COOLER
WEIGHT
(Lbs.)
Oper. Dry
W1LC420 10" x 7’ 4" 13 72-1/2 12-7/8 26 800 700
W1LC530 10" x 7’ 4" 13 72-1/2 12-7/8 26 800 700
*Nominal pipe size - victaulic type.
COOLER DIMENSIONS & WEIGHTS
FRONT 36"
BACK 24"*
LEFT SIDE 24"*
RIGHT SIDE 24"*
TOP 120"
*One side only.
NOTE: The area within the clearances shown above and area under the unit
must be kept clear of all obstructions that would impede free air flow to the
unit. In installations where winter operation is intended and snow accumula-
tions are expected, additional unit height must be provided to insure full air
flow.
CLEARANCES
570.05-N4Y
Unitary Products Group 7

CHECKING THE SYSTEM PRIOR TO
INITIAL START UP
Withthesystem piping andelectricalwiring completed,theunit
is ready to have electrical power applied. Before applying
power, however, the following checks should be made:
1. Compressor shipping brackets have been removed and
rubber isolators installed.
2. The Return Liquid Temperature Contron (TC) has been
adjusted to the desired Return Liquid Temperature and
Between Stage Differential.
3. The Freeze Control thermostat (FC) has been set to the
proper setting. (Factory setting is 36°F.)
4. Fan blades rotate freely.
5. Compressor crankcase oil level shows 1/3 to 1/2 in sight
glass.
6. Suction,dischargeandliquidlinekingvalves,locatedinthe
compressor section, are open. There are two systems in
these units and each system employs one of these valves.
CAUTION: Suction, discharge and liquid line valves are
shipped closed.
7. The power supply voltage is the same as the unit name-
plateu voltage.
8. Proper fuses are in main disconnect power circuits.
APPLYING POWER TO THE UNIT
CAUTION With the preceding steps completed, make sure
the DAY/NIGHT switch is in the NIGHT or UNOC-
CUPIED position or the unit will start immediately
and compressor damage may occur.
1. The main power disconnectswitch maynow beturned ON.
CAUTION: Checktoinsurethatthecompressorcrankcase
heater is energized. Allow at least 24 hours
warm-up to allow all liquid refrigerant to be
driven from the compressors. After warm-up,
the crankcase should be warm to the touch.
2. Startthechilledwatercirculatingpump.Assurethattheflow
rate is approximately correct by checking the water pres-
sure drop across the coolerwith the data shownin Table 5.
3. Check that the liquid freeze prevention thermostat (FC)
does not need to be reset. It may have tripped if the unit
wasexposedtolowoutdoortemperaturesduringshipment.
4. Turn the DAY/NIGHT switch to the DAY or OCCUPIED
position. If the water flow switch is closed, the unit will start
after the required time delays built into the control circuit,
provided the return liquid temperature is warm and the
temperature control (TC) is calling for cooling.
5. Allowtheunittooperate,butbereadytostoptheunitshould
any unusual noise or other adverse condition develop.
NOTE: Opening the DAY/NIGHT switch will only shut the
unit off after completion of the pumpdown cycle.
Turning OFF the main power supply will stop the
unit immediately.
6. To determine if the unitis operatingproperly, the refrigerant
subcooling and superheat should be checked.
SEQUENCE OF OPERATION
NOTE: The contact opening and closing times for 50 HZ
units are 5/6 of those listed for 60 HZ units.
System start-up and staging is controlled by the TC which is
energized through the day/night switch, optional field installed
pump aux. contact, FC and WFS. The FC opens below 36°F
leaving water temperature andcloses above42°F with manual
reset.TheWFS closesatwaterflowratesabove55GPM.The
TC is a solid state thermostat which maintains the desired
chilled (supply) liquid temperature by sensing and regulating
the return liquid temperature (see the ELECTRICAL CON-
TROLS section). It employs an encapsulated thermistor lo-
cated in a well in the return liquid line.
NOTE: The timing intervals described in the following proce-
dure are nominal. Some variations will naturally occur
due to differences in individual components, ambient
temperature, or line/control voltage.
COMPRESSOR NO. 1 OPERATION
When the first stage of the TC calls for cooling.:
1. TC-1 closes and energizes relay 16R. 16R-1 will energize
compressorprotectormoduleMP,andaftera 2minutetime
delay 1MP contacts will close. Contact 16R-3 closes
energizing contactors 1M, 5M, relays 1R, 20R, and timer
1TR. 16R-2 energizes liquid line solenoid valve 1LLS,and
liquid refrigerant will flow to the expansion valve.
2. Relay 1R contacts close, with 1R-1 and 1R-2 closing in
parallel with contacts 16R-1 and 16R-3 respectively main-
taining operation during the pumpdown cycle.
3. Contactor 1M energizes compressor #1, and contactor 5M
energizes the condenser fans #1, #2 and #3. Contact 20R
opensto de-energize compressor crankcase heater1CCH
while the compressor runs.
4. After 2 minutes, low pressure bypass timer 1TR-1 opens.
Ifthecompressorsuctionpressureremainsabnormallylow
after initial start-up, the compressor circuit will lock out as
described in the HIGH / LOW PRESSURE LOCKOUT
section.
When the second stage of the TC calls for cooling:
1. Contacts TC-3 will close to energize relay 4R, and con-
denser fan No. 2 will start up, providing the temperature of
the outdoor air is above the 45°F set point of thermostat
2TH.
2. ContactTC-4willopentode-energizecompressorsolenoid
valve 2SOL, and the 20 ton compressor will operate at full
capacity.
OPERATION
570.05-N4Y
8Unitary Products Group

PART-WINDING START (SYSTEM #1)
Unitswithvoltagesof208/230and380/415havetwocompres-
sorcontactorsandincludepartwindingstart.Onstart-up,timer
4TR prevents contactor 2M from being energized until 1
second after contactor 1M is energized. This 1-second delay
reduces the LRAof the compressor substantially. Refer to the
electrical data in Table 3or 4.
PUMPDOWN (SYSTEM #1)
Whenthecompresorisrunningatpartloadandwhentheliquid
cooling requirementbecomes satisfied, contact TC-1 will open
to de-energize relay 16R. Contact 16R-2 will open tode-ener-
gize liquid line solenoidvalve 1LLS, and no refrigerant will flow
to the 20 ton side of the cooler. Contact 16R-1 will open but
contact1R-2 will keepthe20 toncompressorin operationuntil
the low side of the system is pumped out and low pressure
control LP opens to shut the No. 1 system down.
ANTI-SHORT CYCLING (SYSTEM #1)
WhenlowpressurecontrolLP openstode-energizethe20ton
compressor and the condenser fans, relay 1R will also be
de-energized. 1R-1 opensand de-energizes 1MP.When 1MP
is re-energized, contacts 1MP close after a 2 minute delay
which provides anti-short cycle protection.
OIL FAILURE (SYSTEM #1)
If the oil to suction pressure differential drops below 14 psig (±2),
1 OPA in the oil pressure control will close and energize timer
2TR. If this low pressure condition exists for more than 90
seconds, 2TR contac will open to shut down the compressor
and condenser fans.
HIGH / LOW PRESSURE LOCKOUT (SYSTEM #1)
If the compressor discharge pressure exceeds398 psig or the
suction pressure drops below 30 psig, 1HP or 1LP will open
and shut downthecompressor #1 andoutdoorfans #1, #2and
#3. At the same time, lockout relay 18R will energize. 18R-1
willopenandpreventtheunitfromrestartingwhen1HP or1LP
closes. The unit can be reset by momentarily opening the unit
disconnect switch provided 1HP and 1LP have closed. After
reset, the unit will start after the 2 minute time delay provided
there is a call for cooling.
COMPRESSOR NO. 2 OPERATION
When the third stage of the TC (81) calls for cooling.:
1. TC-5 closes and energizes relay17R. 17R-1 will energize
compressor protector module 2MP, and after a 2 minute
time delay 2MP contacts will close. Contact 17R-3 closes
energizing contactors 3M, 6M, relays 7R, 21R, and timer
5TR. 17R-2 energizes liquid line solenoid valve 2LLS, and
liquid refrigerant will flow to the expansion valve.
2. Relay 7R contacts close, with 7R-1 and 7R-2 closing in
parallel withcontacts 17R-1 and 17R-3 respectively main-
taining operation during the pumpdown cycle.
3. Contactor 3M energizes compressor #2, and contactor 6M
energizes the condenser fans #4, #5 and #6. 21R opens
to de-energize compressor crankcase heater 2CCH while
the compressor runs.
4. After 2 minutes, low pressure bypass timer 5TR-1 opens.
Ifthecompressorsuctionpressureremainsabnormallylow
after initial start-up, the compressor circuit will lock out as
described in the HIGH / LOW PRESSURE LOCKOUT
section.
When the fourth stage of the TC (81) calls for cooling:
1. Contacts TC-7 will close to energize relay 11R and 12R.
2. When relay 11R is energized condenser fan No. 5 will start
up, providing the temperature of the outdoor air is above
the 45°F set point of thermostat 4TH. When relay 12R
closes, condenser fan No. 6 will start.
NOTE: If the temperature of the O.D. air is above the 75
° F
set point of 5TH, condenser fan No. 6 will already
be in operation.
3. Contact TC-8 will open to de-energize compressor sole-
noid valve 4SOLand 5SOLand the 30ton compressor will
operate at full capacity.
PART-WINDING START (SYSTEM #2)
Unitswithvoltagesof208/230and380/415havetwocompres-
sorcontactorsand includepartwindingstart.Onstart-up,timer
8TR prevents contactor 4M from being energized until 1 sec-
ond after contactor 3M is energized. This 1-second delay
reduces the LRA of the compressor substantially. Refer to the
electrical data in Table 3 or 4.
PUMPDOWN (SYSTEM #2)
When the compresor #2 is running at part load and when the
third stage of the TC becomes satisfied, contact TC-5 will
open and de-energize relay 17R. Contact 17R-2 will open to
de-energize liquid line solenoid valve 2LLS, and no refrigerant
will flow to the 30 ton side of the cooler. Contact 17R-1 will
open but contact 7R-2 will keep the 30 ton compressor in
operation until the low side of the system is pumped out and
low pressure control 2LP opens to shut the unit down.
ANTI-SHORT CYCLING (SYSTEM #2)
When low pressure control 2LP opens to de-energize the 30
ton compressor and the condenser fans, relay 7R will also be
de-energized. 7R-1 opens and de-energizes 2MP. When 2MP
is re-energized, contacts 2MP close after a 2 minute delay
which provides anti-short cycle protection.
OIL FAILURE (SYSTEM #2)
If the oil to suction pressure differential drops below 14 psig (±2),
2 OPA in the oil pressure control will close and energize timer
6TR. If this low pressure condition exists for more than 90
seconds, 6TR contact will open to shut down the compressor
and condenser fans.
HIGH / LOW PRESSURE LOCKOUT (SYSTEM #2)
If the compressor discharge pressure exceeds398 psig or the
suction pressure drops below 30 psig, 3HP or 2LP will open
and shut downthecompressor#2 andoutdoorfans#4,#5 and
#6. At the same time, lockout relay 19R will energize. 19R-1
will open and prevent the unit from restarting when 3HP ( or
2LP closes. The unitcan be reset by momentarily opening the
unit disconnect switch provided 3HP and 2LP have closed.
After reset, the unit will start after the 2 minute time delay
provided there is a call for cooling.
570.05-N4Y
Unitary Products Group 9

WATER COOLER FREEZE PREVENTION
Off-cycle cooler freeze protection is provided when liquidis not
flowing to the cooler and the outdoor ambient is low. Under
theseconditions,thewaterflowswitchcontactWFS isrelaxed,
and the cooler heater HTR and 15R relay are energized
through the 7TH thermostat which closes below 36°F. The
cooler heater is a pad type heater fixed to the cooler under the
insulation. The 15R contact closes to energize field installed
water line heaters. The power for these heaters comes from a
separate disconnect switch. See Figure 4.
COMPRESSOR MOTOR PROTECTION SYSTEM
Thesolidstatemotorprotectionsystemconsistsofasolidstate
overload protector moduleand threesensors embedded inthe
compressor motor windings. The sensors areconnectedto the
solid state overload protector module 1MP and 2 MP. Refer to
the wiring label on the inside of the compressor terminal box
cover. This system provides2 minute off-time delaybefore the
compressor can restart.
CONDENSER FAN MOTOR CONTROL
Condenser fans motors cycle with the temperature of the
outdoor air to maintain sufficient head pressure for stable
operation over a wide range of conditions. One condenser fan
motor per compressor can operate at a reduced speed without
overheating. When the discharge pressure drops below 180
psig, the speed of this motor drops from 1075 to 450 RPM.
When the discharge pressure rises above 222 psig, the motor
will return to 1075 RPM. Thisspeed reduction is accomplished
by using a choke coil to reduce the voltage to the motor. A 10
second time delay relay is included in the control circuit so
these motors will always start at highspeed.Refer to Figure 6.
EXAMPLE W1LC420:
NO. 1 (20 TON) SYSTEM - Under 65°F, the #1 condenser fan
will shut off. Under 45°F, the #2 condenser fan will shut off. At
1/2 capacity, the #2 condenser fan will shut off. When the
discharge pressure drops below 180 psig, high pressure con-
trol 2HP will close to energize relay 3R. When contact 3R-1
opens and contact 3R-2 closes, condenser fan #3 will be
powered through choke coil 1CH and its speed will drop to450
RPM. Timer 3TR will remain open for 10 seconds after unit
start-upsothecondenserfan#3willalwaysstartathighspeed.
NO. 2 (20 TON) SYSTEM - Under 65°F, the #4 condenser fan
will shut off. Under 45°F, the #5 condenser fan will shut off. At
1/2 capacity, the #5 condenser fan will shut off. When the
discharge pressure drops below 180 psig, high pressure con-
trol 4HP will close to energize relay 10R. When contact 10R-1
opens and contact 10R-2 closes, condenser fan #6 will be
powered through choke coil 2CH and its speed will drop to450
RPM. Timer 7TR will remain open for 10 seconds after unit
start-upsothecondenserfan#6willalwaysstartathighspeed.
EXAMPLE W1LC530:
NO. 1 (20 TON) SYSTEM - Under 65°F, the #1 condenser fan
will shut off. Under 45°F, the #2 condenser fan will shut off. At
1/2 capacity, the #2 condenser fan will shut off. When the
discharge pressure drops below 180 psig, high pressure con-
trol2HP closetoenergizerelay3R.Whencontact3R-1 opens
and contact 3R-2 closes, condenser fan #3 will be powered
through choke coil 1CH and its speed will drop to 450 RPM.
Timer 3TR will remain open for 10 seconds after unit start-up
so the condenser fan #3 will always start at high speed.
NO. 2 (30 TON) SYSTEM - Under 65°F, the #4 condenser fan
will shut off. Under 45°F, the #5 condenser fan will shut off. At
1/3 capacity, the #5 condenser fan will shut off and the #6
condenser fan will shut off if the ambienttemperature isbelow
75°F.Whenthedischargepressuredropsbelow180psig,high
pressure control 4HP will close to energize relay 10R. When
contact 10R-1 opensand contact 10R-2 closes,condenserfan
#7 will be powered through choke coil 2CH and its speed will
drop to 450 RPM. Timer 7TR will remain open for 10 seconds
after unit start-up so the condenser fan #7 will always start at
high speed.
FIG. 6 - CONDENSER FANS ORIENTATION
570.05-N4Y
10 Unitary Products Group

ELECTRIC CONTROLS
RETURN LIQUID TEMPERATURE CONTROL (TC)
The YORK model TC-6Areturn liquid temperature control is a
4stagesolidstatethermostatthatmaintainsthedesiredchilled
liquid temperature by sensing and regulating the liquid tem-
perature returning to the cooler. The control is mounted in the
compressor compartment, to the left of the main control box in
frontofthesystem2compressor.Thereturnwatertemperature
issensedbyathermistor(SENSOR)locatedinthereturnliquid
line.Its resistance varieswithchanges in returnliquidtempera-
ture. Changes in the thermistor resistance are interpreted by
the controller and are amplified to energize output relay con-
tacts. The circuitry is such that the controller shuts down the
compressor in the event the thermistor is disconnected or
accidentally cut. The return water temperature is adjustable
between 4°F and 70°F. This adjustable range is much greater
than applicable to this chiller. See Table 1 for limitations in
leaving liquid temperatures. The Between Stage Differential is
adjustable between 1°F and 3.75°F.
On both the W1LC420 and 530, the control is factory adjusted
to 54°F Return Liquid Temperature with the Between Stage
Differential set at 2.5°F which results in a 44°F (10°Range)
leaving liquid temperature at nominal conditions. Check that
these settings are still corrector change the settingas required
but do not exceed the application limitations in Table 1.
If the factory temperature control settings which provide 44°F
leavingliquidtemperaturewitha10°Fliquidtemperaturerange
are not desired for the W1LC420 or 530 installation, the re-
quiredleaving liquid temperature and liquid temperature range
must be specified before the new temperature control settings
can be determined. To determine the Between Stage Differen-
tial setpoint on the temperature control for the W1LC420/530,
dividethespecifiedrangeby4.TheReturnLiquidTemperature
setpoint on the control is calculated by adding the specified
liquid temperature range to the specified leaving liquid tem-
perature.
EXAMPLE:
(W1LC420/530)Specified45°Fleavingliquidtemperaturewith
an 8°F liquid temperature range.
Calculate Between Stage Differential Setpoint.
8°F - 4°F = 2°F
Calculate Return Liquid Temperature Setpoint.
45°F + 8°F = 53°F
As an example of how the TC-6Acontrol works in application,
consider the W1LC420 chiller with the control set to maintain
a 54°F return water temperature with a 2.5°F Between Stage
Differential. The flow rate is set to 2.4 GPM/measured TON,
(10°F range) and the workingfluid is water. The W1LC420 is a
4 stage machine with stages at 25%, 50%, 75% and 100%
capacity. All temperatures considered are for a TC-6A control
and thermistor working at design conditions. Allowable toler-
ances could change the actuation temperatures by ±1.25°F.
With the RETURN water temperature to the cooler rising due
to increasing cooling load for the application, the #1 compres-
sor will start at part load when theRETURN water temperature
reaches 47.75°F. The LEAVING water temperature will quickly
drop to 45.25°F. If the cooling load continues to increase, the
#1 compressor will be fully loaded by the controller when the
RETURN water temperature reaches 50.25°F. With increasing
load, the controller will start the #2 compressor at 52.75°F
RETURN water temperature and fully loaded it at 55.25°F.
Under increasingload, the minimum LEAVING water tempera-
tue will be 45.25°F and the maximum 47.75°F. As the demand
for cooling load decreases, the controller will unload compres-
sor stages in reverse order to the way they were loaded at
52.75, 50.25, 47.75 and 47.75°F RETURN watertemperature.
During decreasing load, the minimum LEAVING water tem-
perature will be 42.75°F and the maximum 45.25°F.
FREEZE CONTROL PREVENTION THERMOSTAT (FC)
The leaving liquid freeze prevention thermostat is designed to
prevent the liquid temperature in the cooler from dropping
below the freezing point of the fluid while the unit is running.
CAUTION: Freezing fluid in the cooler can cause damage
which can lead to total replacement of the cooler.
If the temperature of the liquid leaving the cooler drops below
its setpoint thecontrol energizes 2R.2R-1 and2R-2 openand
shut both compressors off immediately. The control must be
manually reset when the bulb temperature rises to 6°F above
the setpoint cutout temperature. The body of the control is in
the compressor compartment attached to the left hand side of
the control box. The sensing bulb is the capillary type located
in a well in the leaving water connection at the far end of the
cooler. This is a cross ambient sensing device that is not
effected by changes in ambient temperature.
The freeze control is factory set to shut down the unit at 36°F
(±2)and ismanuallyresetwhenthe bulbtemperaturereaches
42°F.This settingisfora workingliquidofpurewaterandmany
light brine applications. In heavy brine applications, the control
may be field adjusted using the adjustmentscrew at the top of
the control.
CAUTION: It is recommended that the adjusted cutout tem-
peraturebe atleast 4
° F above thefreezing point of
thefluid.In nobrine applicationshouldthesetpoint
be adjusted below 30 ° F.
If during delivery to the job site or during non-op-
erational periods whenthe ambienttemperatureof
thefreezecontrolbulbdropsbelow36
° F,thefreeze
controlmayhavetrippedandneedstobemanually
reset before the unit will start.
570.05-N4Y
Unitary Products Group 11

GENERAL
It is good practice to include the W1LC chiller in the routine
schedule of daily or weekly operational checks. This should
include but not be limited to checking compressor crankcase
oil level, checking refrigerant liquid line sight glass for proper
charge andsigns of moisture, and checking forobstructions on
the condenser coil such as leaves or paper that would reduce
normal air flow.
WARNING:Prior to performing any service or maintenance,
disconnect all electrical power to the unit.
CLEANING CONDENSER SURFACE
Dirt should not be allowed to accumulate on the condenser
coils.Theundersideofthecoilswillcollectdirtandotherforeign
matter first. Cleaning should be as often as necessary to keep
the condenser coils clean. Use a brush, vacuum cleaner at-
tachment, or other suitable means. Take care so as not to
damage or bend the condenser fins.
LUBRICATING FAN MOTORS
Thecondenserfanmotorsareequippedwithfactorylubricated
and sealed ball bearings, requiring no maintenance.
COMPRESSOR REPLACEMENT
Obtain replacement compressors or parts from your local
Copeland Wholesaler. See Instruction Form 55.72-RD2.2 for
replacement compressor reference data.
SECURE OWNER’S APPROVAL
WHEN THE SYSTEM IS FUNCTIONING PROPERLY, EX-
PLAIN THE OPERATION OFTHE UNIT TO THE OWNER OR
DESIGNATED REPRESENTATIVE. EXPLAIN THE FUNC-
TION OF THE LOCKOUT PROTECTION FEATURES AND
HOW TO RESET THEM. SHOW HIM THE LOCATION OF
ALL DISCONNECT SWITCHES. INSTRUCT HIM HOW TO
STOPAND START THE UNIT.
BE SURE THE WARRANTY REGISTRATION CARD HAS
BEEN FILLED OUT AND RETURNED TO THE FACTORY.
MAINTENANCE
Unitary Products Group
P.O. Box 1592, York, Pennsylvania USA17405-1592
Subject to change without notice. Printed in U.S.A
Copyright  by York International Corporation 1994. All Rights Reserved. Code: SBY
570.05-N4Y