York Millennium YK M3 M3 G4 THRU YK S6 S4 J2 Installation and operation manual

OPERATING & MAINTENANCE
Supersedes: Nothing Form 160.49-O2 (1296)
MILLENNIUM
TM
CENTRIFUGAL LIQUID CHILLERS
MODELYK M3 M3 G4THRUYK S6 S4 J2 (STYLE C)
R-22 (COOLING ONLY)
MODELYK LB LB G4THRUYK SE SC J4 (STYLE C)
R-134a (COOLING ONLY)
WITH MICROCOMPUTER CONTROL CENTER
PART #371-01200-010, 371-01200-011 & 371-01200-015
FOR ELECTRO-MECHANICAL STARTER,
SOLID STATE STARTER & VARIABLE SPEED DRIVE
WW
WW
WARNINGARNING
ARNINGARNING
ARNING
SYSTEM CONTAINS REFRIGERANT UNDER PRESSURE.
SERIOUSINJURYCOULDRESULTIF PROPER PROCEDURESARENOT
FOLLOWED WHEN SERVICING SYSTEM. ALL SERVICE WORK SHALL
BE PERFORMED BY A QUALIFIED SERVICE TECHNICIAN IN ACCOR-
DANCEWITHYORK INSTALLATION/OPERATION MANUAL.
27385A

2YORK INTERNATIONAL
TT
TT
TABLE OF CONTENTSABLE OF CONTENTS
ABLE OF CONTENTSABLE OF CONTENTS
ABLE OF CONTENTS
SECTION 1 – Description of System and
Fundamentals of Operation ......................................... 4
SECTION 2 – MicroComputer Control Center ...................................... 6
SECTION 3 – System Operating Procedures..................................... 30
SECTION 4 – System Component Description .................................. 37
SECTION 5 – Operational Maintenance ............................................. 42
SECTION 6 – Trouble Shooting........................................................... 44
SECTION 7 – Maintenance ................................................................. 49
SECTION 8 – Preventive Maintenance............................................... 58
REFERENCE INSTRREFERENCE INSTR
REFERENCE INSTRREFERENCE INSTR
REFERENCE INSTRUCTIONSUCTIONS
UCTIONSUCTIONS
UCTIONS
DESCRIPTION FORM NO.
Solid State Starter – Operation & Maintenance 160.46-OM3.1
Variable Speed Drive – Operation 160.00-O1
Installation 160.49-N5
Installation and Operation of Printers 160.49-N7
Wiring Diagram – Unit with Electro-Mechanical Starter 160.49-PW7
Wiring Diagram – Field Connections (E-M Starter) 160.49-PW10
Wiring Diagram – Field Control Modifications 160.49-PW13
Wiring Diagram – Control Center with SS Starter 160.49-PW8
Wiring Diagram – Field Connections (SS Starter) 160.49-PW11
Wiring Diagram – Solid State Starter 160.49-PW14
Wiring Diagram – Unit with Solid State Starter 160.49-PW8
Wiring Diagram – Unit with Variable Speed Drive 160.49-PW9
Wiring Diagram – Field Connections (V.S.D.) 160.49-PW12
Wiring Diagram –Variable Speed Drive 160.49-PW15
Page

YORKINTERNATIONAL 3
FORM 160.49-O2
R-22 UNITS
YK N2 N1 H1 – CX C
DESIGN LEVEL (C)
POWERSUPPLY
– for 60 HZ
5 for 50 HZ
COMPRESSOR CODE
G4, H0, H1, H2, J1, J2
CONDENSER CODE
M3, M4, N3, N4, P3, P4, Q3, Q4, R3, R4, S3, S4
COOLER CODE
M3, M4, N3, N4, P3, P4, P5, P6, Q3, Q4, Q5, Q6,
R3, R4, R5, R6, S5, S6
MODEL
{MOTOR CODE:
60 HZ 50 HZ
CH CX 5CE 5CT
CJ CY 5CF 5CU
CK CZ 5CG 5CV
CL CA 5CH 5CW
CM CB 5CI 5CX
CN DA 5CJ 5DA
CP DB 5CK 5DB
CR DC 5CL 5DC
CS DD 5CM 5DD
CT DE 5CN 5DE
CU DF 5CO 5OF
CV DH 5CP 5OG
CW DJ 5CQ 5OH
5CR 5OJ
5CS
R-134a
YK NB PB H1 – CX C
DESIGN LEVEL (C)
POWERSUPPLY
– for 60 HZ
5 for 50 HZ
COMPRESSOR CODE
G4, H0, H1, H2, J1, J2, J3, J4
CONDENSER CODE
LB, LC, MB, MC, NB, NC,
PB, PC, QB, QC, RB, RC, SB, SC
COOLER CODE
LB, LC, MB, MC, NB, NC, PB, PC, PD, PE,
QB, QC, QD, QE, RB, RC, RD, RE, SD, SE
MODEL
{MOTOR CODE:
60 HZ 50 HZ
CH CX 5CE 5CT
CJ CY 5CF 5CU
CK CZ 5CG 5CV
CL CA 5CH 5CW
CM CB 5CI 5CX
CN DA 5CJ 5DA
CP DB 5CK 5DB
CR DC 5CL 5DC
CS DD 5CM 5DD
CT DE 5CN 5DE
CU DF 5CO 5DF
CV DH 5CP 5DG
CW DJ 5CQ 5DH
5CR 5OJ
5CS
NOMENCLATURE

4YORK INTERNATIONAL
SECTION 1
DESCRIPTION OF SYSTEM AND FUNDAMENTALS OF OPERATION
FIG. 1 – MODELYK MILLENNIUM CHILLER
SYSTEM OPERATION DESCRIPTION (See Fig. 2)
The YORK Model YK Millennium Chiller is commonly
applied to large air conditioning systems, but may be
used on other applications. The chiller consists of an
open motor mounted to a compressor (with integral
speed increasing gears) condenser, cooler and flow
control chamber.
The chiller is controlled by a modern state of the art
MicroComputer Control Center which monitors its op-
eration.The Control Center is programmed by the op-
erator to suit job specifications. Automatic timed start-
ups and shutdowns are also programmed to suit
nighttime, weekends, and holidays.The operating sta-
tus,temperatures, pressures, andother informationper-
tinent to operation of the chiller are automatically dis-
played and read on a 40 character alphanumeric
message display. Other displays can be observed by
pressing the keys as labeled on the Control Center.
The chiller with the MicroComputer Control Center is
applied with an electro-mechanical starter,YORK Solid
State Starter (optional), or Variable Speed Drive (op-
tional).
In operation, a liquid (water or brine to be chilled) flows
through the cooler, where boiling refrigerant absorbs
heat from the water. The chilled liquid is then piped to
fan coil units or other air conditioning terminal units,
where it flows through finned coils, absorbing heat from
the air.The warmed liquid is then returned to the chiller
to complete the chilled liquid circuit.
The refrigerant vapor, which is produced by the boiling
action in the cooler, flows to the compressor where the
rotating impeller increases its pressure and tempera-
ture and discharges it into the condenser.Water flowing
through the condenser tubes absorbs heat from the re-
frigerant vapor, causing it to condense.The condenser
water is supplied to the chiller from an external source,
usuallyacooling tower.Thecondensedrefrigerantdrains
fromthe condenserintothe flowcontrolchamber,where
the flow restrictor meters the flow of liquid refrigerant
to the cooler to complete the refrigerant circuit.
Themajorcomponents ofachiller areselected tohandle
the refrigerant which would be evaporated at full load
CONTROL
CENTER
COMPRESSOR
MOTOR
COOLER
27382A
DISCHARGELINE PRE-ROTATION
VANE
ACTUATOR
CONDENSER
OILRESERVOIR/
PUMP
27385A

YORKINTERNATIONAL 5
FORM 160.49-O2
7619A(D)
DETAIL A – COMPRESSOR PREROTATION VANES
designconditions.However, mostsystemswill becalled
upon to deliver full load capacity for only a relatively
small part of the time the unit is in operation.
CAPACITY CONTROL
The major components of a chiller are selected for full
loadcapacities,thereforecapacity mustbecontrolled to
maintain a constant chilled liquid temperature leaving
the cooler. Prerotation vanes (PRV), located at the en-
tranceto thecompressor impeller, compensateforvaria-
tion in load (See Fig. 2. Detail A).
The position of these vanes is automatically controlled
through a lever arm attached to an electric motor lo-
cated outside the compressor housing. The automatic
adjustment of the vane position in effect provides the
performance of many different compressors to match
various load conditions from full load with vanes wide
open to minimum load with vanes completely closed.
FIG. 2 – REFRIGERANT FLOW-THRU CHILLER
PREROTATIONVANES
(SeeDetail A)
SUCTION
COOLER
ELIMINATOR
OILCOOLER
LD00924
FLOWCONTROL
ORIFICE
SUB-COOLER
CONDENSER
DISCHARGE
BAFFLE
DISCHARGE
COMPRESSOR

6YORK INTERNATIONAL
SECTION 2
MICROCOMPUTER CONTROL CENTER
LD00953
26879A
FIG. 3 – MICROCOMPUTER CONTROL CENTER AND KEYPAD
NOTE: This instruction covers operationof chillersequippedwith Electro-Mechanicalor SolidState Starters.Ifchiller
is equipped with Variable Speed Drive, Form 160.00-O1 is to be used in conjunction with this manual.
WARNING
This equipment generates, uses and can radiate radio frequency energy and if not installed and used in accor-
dance with the instructions manual, may cause interference to radio communications.Operation of this equip-
ment in a residential area is likely to cause interference in which case the user at his own expense will be
required to take whatever action may be required to correct the interference.
Additionally, anyelectronicequipment cangenerate EMI(electromagnetic interference) which,depending upon
the installation and magnitude, may affect other electronic equipment.The amount of EMI generated is deter-
mined by the source inductance, load inductance, and circuit impedances. Responsibility for assuring the
satisfactory operation of other equipment included in the same power source as the YORK equipment rests
solely with the user.YORK disclaims any liability resulting from any interference or for the correction thereof.

YORKINTERNATIONAL 7
FORM 160.49-O2
INTRODUCTION
The YORK MicroComputer Control Center is a micro-
processorbased controlsystem forR-22 orR134a cen-
trifugal chillers.It controls the leaving chilled water tem-
peraturevia pre-rotationvanecontroland hasthe ability
tolimitmotor currentviacontrol ofthe pre-rotationvanes.
Further, it is compatible with YORK Solid State Starter
(optional),Variable Speed Drive (optional), and electro-
mechanical starter applications.
A keypad mounted on the front of the Control Center
(see Fig.3) allows the operator to display system oper-
ating parameters on a 40 character alphanumeric dis-
play that is part of the keypad.These readings are dis-
played via “Display” keypad as follows: (In the English
mode; temperatures in °F, pressures in (PSIG) (in the
metric mode, temperatures in °C, Pressures in KPa).
If unit is equipped with EPROM version C.02F(T).12 or
later, the Control Center can be equipped with an op-
tional Chinese language display, either as a field retrofit
or factory supplied option on new units. This display
mounts on the control center door, directly above the
standard display. Both the standard and Chinese dis-
play will be present, providing display messages simul-
taneously in both English and Chinese language.
The Control Center must be configured for Chinese dis-
play by a qualified service technician. Instructions are
contained inYORK service manual, Form 160.49-M3.
• CHILLED LIQUID TEMPERATURES – LEAVING AND
RETURN
• REFRIGERANT PRESSURES – EVAPORATOR AND
CONDENSER
• DIFFERENTIAL OIL PRESSURE
• CONDENSER LIQUIDTEMPERATURES – OPTIONAL
FIELD INSTALLED – LEAVING AND RETURN
• OPTIONS
• PRINT *
• HISTORY PRINT *
• MOTOR CURRENT IN % OF FULL LOAD AMPS
• SATURATIONTEMPERATURES–EVAPORATORAND
CONDENSER
• DISCHARGETEMPERATURE
• OILTEMPERATURE
• HIGH & LOW OIL PRESSURETRANSDUCER PRES-
SURE
• SOLID STATE STARTER MOTOR CURRENT / VOLTS
(When Supplied)
• CONDENSER REFRIGERANT LEVEL
The system setpoints (see Fig.3) are operator entered
on the front control center Setpoints keypad. These
setpoints can also be displayed on the 40 character al-
phanumeric display.The system setpoints are:
• CHILLED LIQUIDTEMPERATURE (LCWT)
• % CURRENT LIMIT
• PULLDOWN DEMAND LIMIT
• CLOCK (TIME-OF-DAY)
• DAILY SCHEDULE (7 DAY TIME-CLOCK PROGRAM-
MING)
• HOLIDAY
• REMOTE RESETTEMPERATURE RANGE
• DATA LOGGER
• CONDENSER REFRIGERANT LEVEL
Thecause ofall system shutdowns (safety orcycling) is
preserved (until the system is reset or restarts) in the
microcomputer’smemory forsubsequent viewingon the
keypad display. The operator is continually advised of
systemoperating conditionsbyvariousbackground and
warning messages. The keypad contains special ser-
vice keys for use by the service technician when per-
forming system troubleshooting.
The MicroComputer Control Center is designed to be
compatible with most Energy Management Systems
(EMS) in use today. The standard design allows for the
following EMS interface:
1. Remote Start
2. Remote Stop
3. Remote LCWT Setpoint (Pulse Width Modulated sig-
nal)
4. Remote Current Limit Setpoint (PulseWidth Modulated
signal)
5. A “Remote Mode Ready to Start” Status Contacts
6. Safety Shutdown Status Contacts
7. Cycling Shutdown Status Contacts
As an enhancement to the standard EMS features, an
optional card file with plug-in printed circuit boards is
available. These optional cards will accept a remote
LCWT 0 to 10°F or 0 to 20°F setpoint offset and/or re-
mote current limit setpoint interface from three user in-
put choices.
1. 4-20mA
2. 0-10VDC
3. Contact Closures
*These keys provide a print-out when the customer connects a com-
patible printer to the Micro Board RS-232 serial port. (See Form
160.49-N7.)

8YORK INTERNATIONAL
CONTROL CENTER
The Control Center front panel layout consists of five
key groups, one switch and a 1 line by 40 character al-
phanumeric vacuum fluorescent display: (see Fig.3.)
CHARACTERISTIC DISPLAY – The alphanumeric
vacuum fluorescent display is located to the right of the
STATUS key. All messages,parameters,setpoints,and
data can be viewed at this location.The main communi-
cations between the operator or service technician and
the MicroComputer Control Center occurs on this dis-
play.
DISPLAY – Provide a direct readout of each monitored
parameter on the alphanumeric display.
ENTRY – These keys are used to enter the values for
theoperatorprogrammedsetpoints.Thesekeysareused
in conjunction with the Setpoint keys while in PRO-
GRAM mode.
SETPOINTS – These keys are used as follows:
1. To view each setpoint, in any mode, or
2. To selectthe individualsetpointsthatare programmed
by the operator in PROGRAM mode only.
Pressing the appropriate key enables the operator to
program that setpoint pressing the Entry keys.
SERVICE – Includedin thisgroupofkeysarethosefunc-
tions that are only relevant to servicing the chiller.
Typically, these keys would not be used for daily chiller
operation.
ACCESS CODE – Permits operator to access the pro-
gram.
PROGRAM – Permits operator to program the Control
Center.
MODE – Permitsoperatorto check whatmodethe Con-
trol Center is presently in (LOCAL, REMOTE or SER-
VICE).
1. Service – allows manual PRV control with visual
display readout of PRV operation.
2. Local – allows manual compressor start from the
COMPRESSOR switch on the Control Center front.
3. Program – allows operator programming of system
setpoints.
4. Remote – allows remote start, remote stop of com-
pressor and remote reset of LCWT and % current
limit.
COMPRESSOR-START, RUN, STOP/RESET
SWITCH – This 3-position rocker switch is used to start
(except in REMOTE mode), stop/run/reset the system.
OPERATION
DISPLAYING SYSTEM PARAMETERS
The Display keys are used to display selected
monitored parameters as follows: (Refer to Fig. 3.)
• Press and release the appropriate Display key – the
message will be displayed for 2 seconds.
– or –
• Pressand holdthe appropriateDisplaykey –the mes-
sage will be displayed and updated every 0.5 sec-
onds until the Display key is released.
– or –
• Pressand releaseappropriateDisplaykey,thenpress
and release the DISPLAY HOLD key – the message
will be displayed and updated every 2 seconds until
the DISPLAY HOLD key is again pressed and re-
leased,or10 minuteshaveelapsed, whichevercomes
first.
NOTE: If the display actually displays X’s, then the
monitored parameter is out of normal operat-
ingrange(refer toFig.4).Ifthe“English/Metric”
jumper is installed on the Micro Board, all tem-
peratures are displayed in degrees Fahrenheit
(°F) and all pressures are displayed in pounds
per sq. inch gauge (PSIG) except oil pressure
whichis displayedin poundsper sq.inch differ-
ential (PSID). If the “English/Metric” jumper is
not installed, all temperatures are displayed in
degrees Centigrade (°C) and all pressures are
displayed in Kilo-Pascals (kPa).

YORKINTERNATIONAL 9
FORM 160.49-O2
To Display CHILLED LIQUID TEMPERATURES:
Press CHILLED LIQUIDTEMPS display key as de-
scribed onpage 7toproduce thefollowingalphanu-
meric display message:
CHILLED LEAVING = XXX.X°F, RETURN = XXX.X°F
To Display REFRIGERANT PRESSURE:
Use REFRIGERANT PRESSURE display key as
described onpage 7toproduce thefollowing alpha-
numeric display message:
EVAP = XXX.X PSIG; COND = XXX.X PSIG
To Display OIL PRESSURE:
Use OIL PRESSURE display key as described on
page 7 to produce the following alphanumeric dis-
play message:
OIL PRESSURE = XXXX.X PSID
The differential pressure displayed is the pressure dif-
ference between the high side oil pressure transducer
(output of oil filter) and the low side oil pressure trans-
ducer (compressor housing). Displayed value includes
offset pressure derived from auto-zeroing during
“START SEQUENCE INITIATED”. If either transducer
is out-of-range, XX.X is displayed. Oil pressure is
calculated as follows:
______ PSID = (HOP – LP) – OFFSET PRESSURE
OFFSET PRESSURE: Pressure differential between
the HOP transducer and LOP transducer outputs dur-
ing a 3 second period beginning 10 seconds after the
start of “START SEQUENCE INITIATED”. During this
time, the transducers will be sensing the same pres-
sure and their outputs should indicate the same pres-
sure. However, due to accuracy tolerances in trans-
ducer design, differences can exist.Therefore, to com-
pensate for differences between transducers and as-
sure differential pressure sensing accuracy, the OFF-
SET PRESSURE is subtracted algebraically from the
differential pressure. The offset pressure calculation
willnot beperformedif eithertransduceris out-of-range.
The offset value will be taken as 0 PSI in this instance.
To Display OPTIONS:
This key is not used.
NO OPTIONS INSTALLED
is displayed when this key is pressed.
To Display SSS MOTOR CURRENT /VOLTS:
(Solid State Starter Applications Only)
Ifchillerisequipped withaYORKSolid StateStarter,
use SSS MOTOR CURRENT / VOLTS key to dis-
play3-phasecompressor motorcurrent and3-phase
Solid State Starter input line voltage.
Continuously pressing this key will display the mo-
tor current and line voltage alternately.When used
with the DISPLAY HOLD key, motor current and
line voltage will alternately be displayed each time
this key is pressed.The messages are as follows:
A AMPS = XXXX; B AMPS = XXXX; C AMPS = XXXX
V A-B = XXXX; VB-C = XXXX; V C-A = XXXX
If chiller is not equipped with a Solid State Starter,
this key produces the following message:
SOLID STATE STARTER NOT INSTALLED
In PROGRAM mode, this key is used to display the
applicable line voltage range (200-208VAC, 220-
240VAC, 380VAC, 400VAC, 415VAC, 440-480VAC,
500-600VAC, SupplyVoltageRange Disabled).The
correct line voltage range is programmed at the
YORK factory and is checked by the service tech-
nician at start-up. For security reasons, a special
access code is required to program the line volt-
age range.The line voltage range is used to deter-
mine a low line voltage threshold for cycling shut-
down. Refer to “System Setpoints” for Trip/Reset
values.
DISPLAY
READS
CONDENSER PRESS. = < 6.8 PSIG, or > 300 PSIG XX.X PSIG
EVAPORATOR PRESS. = < 50 PSIG, or > 125 PSIG XX.X PSIG
EVAP.PRESS.(BRINE) = < 25 PSIG, or > 100 PSIG XX.X PSIG
HOPTRANSDUCER = < 59.1 PSIG, or > 314.9 PSIG XX.X PSIG
LOPTRANSDUCER = < 23.2 PSIG, or > 271.8 PSIG XX.X PSIG
DISCHARGETEMP. = < 20.3°F; > 226.4°F XXX.X°F
OILTEMP. = < 20.3°F; > 226.4°F XXX.X°F
LEAVING CONDENSER
WATER TEMP. = < 8.4°F; > 134.1°F XXX.X°F
ENTERING CONDENSER
WATER TEMP. = < 8.4°F; > 134.1°F XXX.X°F
LEAVING EVAPORATOR = < 0°F XX.X°F
WATER TEMP. = > 81.1°F XX.X°F
ENTERING EVAPORATOR = < .1°F XX.X°F
WATER TEMP. = > 93°F XX.X°F
FIG. 4 – SYSTEM PARAMETERS – OUT OF
RANGE READINGS

10 YORK INTERNATIONAL
To Display CONDENSER LIQUID TEMPERATURES
(Field Installed Option Package):
Use CONDENSER LIQUIDTEMPS display key as
described above to produce the following alphanu-
meric display message:
COND LEAVING = XXX.X°F; RETURN = XXX.X°F
NOTE: If the condenser liquid thermistors are not con-
nected, or both thermistors are “out of range”,
the display will blank when this key is pressed.
To Initiate a PRINT to Printer:
Press the PRINT key to initiate a printout to an op-
tional printer.When the key is pressed,
PRINT ENABLE is displayed.
Refer to “MicroComputer Control Center – System
StatusPrinters”instruction,Form 160.49-N7forde-
tails of the optional printers.
To Display MOTOR CURRENT:
Press the % MOTOR CURRENT display key as
described above to display motor current as a per-
cent of Full Load Amps (FLA). The message is as
follows:
MOTOR CURRENT = XXX% FLA
NOTE: • Liquid-CooledSolid StateStarterApplications
– the % Motor Current displayed is the highest
ofthreeline currentsdivided bytheprogrammed
chiller FLA value x 100%.
• Electro-MechanicalStarterApplications – the
% Motor Current displayed is the highest of the
three line currents.
To Display OPERATING HOURS and STARTS
COUNTER:
Use the OPERATING HOURS key as described on
page 8, to produce the following message:
OPER. HOURS = XXXXX; START COUNTER = XXXXX
NOTE: The operating hours and starts counter can be
reset to zero.Refer to“Programming the Micro-
Computer Control Center”, page 14. However,
the purpose of the OPERATING HOURS key
is to display the total accumulated chiller run
time.Therefore, the operating hours should not
be arbitrarily reset.
SYSTEM SETPOINTS
The system setpoints may be programmed by the sys-
tem operator. The Setpoints keys are located on the
ControlCenterkeypad(seeFig.3).To program,see“Pro-
gramming System Setpoints”, page 14. The following
is a description of these setpoints (with the English/
Metric jumper installed on the Micro Board):
CHILLED LIQUID TEMP – This key displays the leav-
ingchilledwatertemperature(LCWT) setpointin degrees
Fahrenheit.Ifnot programmed,the defaultvalueis 45°F.
See “Programming System Setpoints”, page 15).
NOTE: If an Energy Management System is interfaced
to the Control Center for the purpose of remote
LCWT setpoint reset, then the operator-pro-
grammed chilled liquid temperature will be the
base or lowest setpoint available to the Energy
Management System (EMS).This chilled liquid
temperaturevaluemust alsobeentered intothe
EMS. Further, any subsequent change to this
value must also be entered into the EMS.
% CURRENT LIMIT – This key displays the maximum
valueofmotor currentpermitted byits programmedset-
ting.The value is in terms of percent of Full Load Amps
(FLA).Ifnot programmed,the default valueis100%.(See
“Programming System Setpoints”, page 15.)
If chiller is equipped with a YORK Solid State Starter,
the system FLA is also displayed. This value is pro-
grammed by the factory and should never be changed.
The Micro Board uses this value to calculate and dis-
play the % motor current parameter that is displayed
whenthe % MOTOR CURRENT display keyis pressed.
Also, proper current limit control depends on the cor-
rectly programmed FLA value. For security reasons, a
specialaccesscodeisrequiredtoprogramtheFLAvalue.
It should only be changed by a service technician.
PULL DOWN DEMAND – This function is used to pro-
vide energy savings following the chiller start-up. This
key displays a programmable motor current limit and a
programmable period of time. Operation is as follows:
Whenever the system starts, the Pull Down Demand
Limit is maintained for the programmed time, then the
current limit control returns to % current limit setpoint.
The maximum permitted motor current is in terms of %
FLA.The duration of time that the current is limited is in

YORKINTERNATIONAL 11
FORM 160.49-O2
terms of minutes (to a maximum of 255). If not pro-
grammed, the default value is 100% FLA for 00 min-
utes.(See“Programming SystemsSetpoints”,page 16.)
Thus, no pull down demand limit is imposed following
system start, and the % current limit setpoint is used.
CLOCK – This keydisplaysthe day ofthe week,time of
day and calendar date. If not programmed, the default
value is SUNDAY 12:00 AM 1/1/92 .
(See “Programming System Setpoints”, page 16.)
DAILYSCHEDULE – This keydisplaystheprogrammed
daily start and stop times, from Sunday thru Saturday
plus Holiday. If desired, the Control Center can be pro-
grammed to automatically start and stop the chiller as
desired.This schedule will repeat on a 7-day calendar
basis.If the Daily Schedule is not programmed, the de-
fault value is 00:00 AM start and stop times for all days
of the week and the holiday. (Note that the system will
not automatically start and stop on a daily basis with
these default values because 00:00 is an “Impossible”
time for the Micro Board. See “Programming System
Setpoints”, page 17.) Finally, one or more days in the
week can be designated as a holiday (see description
under HOLIDAY setpoint) and the Control Center can
be programmed (usually Daily Schedule setpoint) to
automatically start and stop the chiller on those days so
designated. The operator can override the time clock
at any time using the COMPRESSOR switch.
Note that if only a start time is entered for a particular
day, the compressor will not automatically stop until a
scheduled stop time is encountered on a subsequent
day.
HOLIDAY – This keyindicateswhichdaysin theupcom-
ing week are holidays. On those designated days, the
chiller will automatically start and stop via the holiday
start and stoptimes programmed in the DAILY SCHED-
ULE setpoint.It will do this one time only and the follow-
ing week will revert to the normal daily schedule for that
day.
REMOTE / RESETTEMP RANGE – This key displays
themaximumoffset ofremoteLCWT setpointreset.This
offset is either 10° or 20°F as programmed.When in the
REMOTE mode, thisvalueis addedto theoperatorpro-
grammedCHILLED LIQUIDTEMP setpointandthe sum
equals the temperature range in which the LCWT can
be reset. For example, if the operator programmed
CHILLED LIQUIDTEMP setpoint isprogrammedwitha
valueof 10°F, then the CHILLED LIQUIDTEMP setpoint
can be remotely reset over a range of 46°F to 56°F (46
+ 10 = 56).If not programmed, the default value for this
parameter is 20°F.
For additional information on remote LCWT reset, refer
to Form 160.49-PW13.
NOTE: If an Energy Management System is interfaced
to the Control Center for the purpose of remote
LCWT setpoint reset, then the operator pro-
grammed REMOTE RESET TEMP RANGE
value determines the maximum value of tem-
perature reset controlled by the Energy Man-
agement System.
DATE LOGGER – This key is used when an optional
printer isconnected tothe MicroComputerControlCen-
ter. Refer to Form 160.49-N7 for operation instructions.
SSS MOTOR CURRENT/VOLTS – This key is used on
Solid State Starter applications only. Although this is a
display key, it is used to program the applicable AC
power line voltage range (380VAC, 400VAC, 415VAC,
440-480VAC, 550-600VAC). The MicroComputer Con-
trol Center uses this entry to determine the under-volt-
age and overvoltage shutdown threshold. For each
line voltage category, there is an undervoltage and ov-
ervoltage shutdown threshold.If the AC power line volt-
age exceeds these thresholds for 20 continuous sec-
onds, the chiller shuts down and displays
MON 10:00 AM LOW LINE VOLTAGE
– or –
MON 10:00 AM HIGH LINE VOLTAGE
This overvoltage and undervoltage protection can be
disabled.Refer to chart below:
For security reasons, a special access code is required
toprogramthe supplyvoltagerange.Thesupply voltage
range is programmed at the factory and should only be
changed by a service technician.
LOW / HIGH LINEVOLTAGETRIP / RESETVALUES
COMPRESSOR LOW LINEVOLTAGE HIGH LINEVOLTAGE
MOTOR OPERATING POINT OPERATING POINT
SUPPLYVOLTAGE CUTOUT-(V) CUTIN-(V) CUTOUT-(V) CUTIN-(V)
RANGE – (V) (ON FALL) (ON RISE) (ON RISE) (ON FALL)
380 305 331 415 414
400 320 349 436 435
415 335 362 454 453
440-480 370 400 524 523
550-600 460 502 655 654
Supply Voltage NONE 0 NONE 0
Range Disabled

12 YORK INTERNATIONAL
DISPLAYING SYSTEM SETPOINTS
The currently programmed Setpoint values can be
viewed at any time (see page 22) in SERVICE, LOCAL
or REMOTE operating mode as follows:
• Press and release the appropriate Setpoint key– the
message will be displayed for 2 seconds.
– or –
• Press and hold the appropriate Setpoint key – the
message will be displayed as long as the key is
pressed.
– or –
• Press and release the appropriate Setpoint key, then
press and release the DISPLAY HOLD key.The mes-
sagewill bedisplayeduntil theDISPLAY HOLD keyis
again pressed and released, or 10 minutes have
elapsed, whichever comes first.
To Display CHILLED LIQUIDTEMP Setpoint:
Use CHILLED LIQUID TEMP setpoint key as de-
scribed on page 10 to produce the following mes-
sage:
LEAVING SETPOINT = XX.X °F
NOTE: Thevaluedisplayedisthe actualLCWT setpoint.
For example, the value displayed in LOCAL or
PROGRAM modesis thatwhichis operatorpro-
grammed. ThevaluedisplayedintheREMOTE
modeis thatbase setpointwithaddedtempera-
ture reset by an Energy Management System,
viaremote LCWTsetpoint (PWMsignal) ifa re-
mote reset signal was received within 30 min-
utes.
To Display % CURRENT LIMIT Setpoint:
Use % CURRENT LIMIT setpoint key as described
above to produce the following message:
CURRENT LIMIT = XXX % FLA
NOTE: The valuedisplayed isthe actual% currentlimit
setpoint. For example, the value displayed in
LOCAL or PROGRAM mode is that which is
operator programmed. The value displayed in
the REMOTE mode is that which has been pro-
grammed by the Energy Management System
via the remote current limit setpoint input.
If chiller is equipped with a YORK Solid State Starter,
the message is:
CURRENT LIMIT = XXX % FLA; *MTR CUR = 000 FLA
NOTE: On SolidState Starterapplications,this value is
programmed at theYORK factory.A special ac-
cess code is required.
To Display PULL DOWN DEMAND Setpoint:
Use PULL DOWN DEMAND setpoint key as de-
scribed on page 10 to produce the following mes-
sage:
SETPOINT = XXX MIN @ XX % FLA XXX MIN LEFT
To Display CLOCK Setpoint (Time of Day):
Use CLOCK setpoint key as described above to
produce the following message:
TODAY IS DAY XX:XX AM/PM 1/1/92
To Display DAILY SCHEDULE Setpoints:
• Press and hold the DAILY SCHEDULE setpoint key.
The chiller start and stop times for each day of the
week are sequentially displayed, beginning with Sun-
day and ending with Holiday.The display will continu-
ously scroll until the DAILY SCHEDULE key is re-
leased. – or –
• Pressandrelease theDAILYSCHEDULEsetpointkey.
Then press and release the DISPLAY HOLD key.The
chiller start and stop times for each day of the week
aresequentially displayedbeginningwith Sundayand
endingwithHoliday.Thedisplaywillcontinuously scroll
until the DISPLAY HOLD key is again pressed and
released, or 10 minutes have elapsed, whichever
comes first.
The display message for DAILY SCHEDULE will scroll
in the following sequence:
SUN START = 08:30 AM STOP = 06:00 PM
MON START = 05:00 AM STOP = 07:00 PM

YORKINTERNATIONAL 13
FORM 160.49-O2
TUE START = 05:00 AM STOP = 07:00 PM
WED START = 05:00 AM STOP = 07:00 PM
THU START = 05:00 AM STOP = 07:00 PM
FRI START = 05:00 AM STOP = 07:00 PM
SAT START = 05:00 AM STOP = 01:00 PM
HOL START = 00:00 AM STOP = 00:00 PM
To Display HOLIDAY Setpoints:
Use HOLIDAY setpoint key as described in the be-
ginningof thissection toproducethefollowingmes-
sage:
S_ M_ T_ W_ T_ F_ S_ HOLIDAY NOTED BY *
NOTE: On the days that are designated by an *, the
chiller will automatically start and stop per the
holidayschedule establishedin DAILY SCHED-
ULE setpoints.
To Display REMOTE RESET TEMP RANGE Setpoint:
Use REMOTE RESET TEMP RANGE setpoint key
as described above to produce the following mes-
sage:
REMOTE RESET TEMP RANGE = 10°F
– or –
REMOTE RESET TEMP RANGE = 20°F
To Display DATA LOGGER setpoints:
RefertoYORK,Form 160.49-N7foroperationof this
key.
To Display UNDERVOLTAGE setpoints:
(Solid State Starter Applications Only)
PressSSS MOTOR CURRENT/VOLTS keyin PRO-
GRAM mode to display the selected voltage range.
One of the following messages will be displayed.
SUPPLY VOLTAGE RANGE 380
– or –
SUPPLY VOLTAGE RANGE 400
– or –
SUPPLY VOLTAGE RANGE 415
– or –
SUPPLY VOLTAGE RANGE 440-480
– or –
SUPPLY VOLTAGE RANGE 550-600
– or –
SUPPLY VOLTAGE RANGE DISABLED
A special access code is required to program the Sup-
ply Voltage Range. The Supply Voltage Range is pro-
grammedatthe factoryand checkedat systemstart-up.
(Note to service technician: Refer to programming in-
structions in Service Instruction, Form 160.49-M3.)

14 YORK INTERNATIONAL
PROGRAMMING
THE MICROCOMPUTER CONTROL CENTER
FIG. 5 – KEYPAD – PROGRAMMING SYSTEM
SETPOINTS
PROGRAMMING SYSTEM SETPOINTS
The system setpoints can be entered at any time .. .. .
even when the system is running.Proceed as follows to
enter system setpoints.(Refer to Fig.5.)
1. Press ACCESS CODE key.
2. ENTER VALID ACCESS CODE _ _ _ _ is displayed.
3. Using ENTRY keys, enter 9 6 7 5.
4. As each digit is entered, the characters Y O R K are
displayed.
NOTE: If digits other than 9 6 7 5 are entered,
YORKis still displayed.
NOTE: Forease inrememberingthe code,note that
theletters YORKcorrespondto thedig-
its 9675on a telephone dial .
5. Press ENTER key.
NOTE: Ifdigitsotherthan9675wereentered instep
No. 4, INVALID ACCESS CODE is displayed
when the ENTER key is pressed. If this oc-
curs, enter the correct access code (9675)
and proceed.
6. ACCESS TO PROGRAM KEY AUTHORIZED is displayed.
NOTE: Unless terminated by pressing theACCESS
CODE key again, the operator will have ac-
cess to the PROGRAM key for 10 minutes.
When 10 minutes have elapsed, access to
PROGRAM keywillbeautomatically disabled
and the operator must return to step No.1 to
gain access.
7. Press PROGRAM key.
8. PROGRAM MODE, SELECT SETPOINT is displayed.
9. Entersetpoints asdetailed below.If you makea mis-
takewhen enteringa value,press CANCEL keyand
thenENTER key.Thedisplaywillrevert tothedefault
values and the cursor will return to the first change-
able digit.You can then proceed to enter the correct
values.If the entered value exceeds acceptable lim-
its, OUT OF RANGE – TRY AGAIN!
message will be displayed for 2 seconds, then the
PROGRAM MODE, SELECT SETPOINT message will re-
appear.
10.When all the desired setpoints have been entered,
press the ACCESS CODE key to exit PROGRAM
mode and terminate access to PROGRAM mode.
ACCESS TO PROGRAM MODE DISABLED is displayed.
The Control Center will automatically return to LO-
CAL, REMOTE or SERVICE mode . . . . whichever
was last selected.
LD00954

YORKINTERNATIONAL 15
FORM 160.49-O2
To enter CHILLED LIQUID TEMP Setpoint: (Refer to
Fig.6.)
1. Press andreleaseCHILLED LIQUID TEMP setpoint
key.The following program prompt message will be
displayed:
LEAVING SETPOINT = XX.X °F (BASE)
(BASE) refers to the base or lowest setpoint avail-
able to an Energy Management System.If any En-
ergyManagementSystemis applied,this valuemust
be entered into the Energy Management System.
Refer to previous explanation or REMOTE/RESET
TEMP RANGE, page 11.
2. Use ENTRY keys to enter desired value.
3. Press and release ENTER key.
PROGRAM MODE, SELECT SETPOINT
message is displayed.
FIG. 6 – KEYPAD – PROGRAMMING “LEAVING
CHILLED WATER TEMP” SETPOINT
To Enter % CURRENT LIMIT Setpoint:
(Electro-Mechanical Starter, refer to Fig.7)
1. Press and release % CURRENT LIMIT setpointkey.
Thefollowingprogramprompt messageis displayed:
CURRENT LIMIT = XXX% FLA
2. Use ENTRY keys to enter desired value.
3. Press and release ENTER key.
PROGRAM MODE, SELECT SETPOINT
message is displayed.
(Solid State Starter, refer to Fig.7)
1. Press and release % CURRENT LIMIT setpointkey.
Thefollowingprogramprompt messageis displayed:
CURRENT LIMIT = XXX% FLA; MTR CUR = _ _ _ FLA
2. Use ENTRY keys to enter desired value.
NOTE: Motor CurrentFLA valueis enteredbyYORK
factory and checked at system start-up. It
cannot be changed without special access
code. (Note to service technician: refer to
“Programming Instructions” in Service in-
struction, Form 160.49-M3.
3. Press and release ENTER key.
PROGRAM MODE, SELECT SETPOINT
message is displayed.
FIG. 7 – KEYPAD – PROGRAMMING “% CURRENT
LIMIT” SETPOINT
LD00955
LD00956

16 YORK INTERNATIONAL
To Enter PULL DOWN DEMAND Setpoint:
(Refer to Fig.8.)
1. Press and release PULL DOWN DEMAND setpoint
key.The following program prompt message is dis-
played:
SETPOINT = XXX MIN @ XXX % FLA, XXX MIN LEFT
2. Use Entry keys to enter desired values. For expla-
nation, see PULL DOWN DEMAND, page 12.Note
that “XX min left”is not an operator entered value.
3. Press and release ENTER key.
PROGRAM MODE, SELECT SETPOINT
message is displayed.
FIG. 8 – KEYPAD – PROGRAMMING “PULL DOWN
DEMAND” SETPOINT
To Enter CLOCK Setpoint: (Refer to Fig.9.)
1. Assure Micro Board Program jumper J57 is in
“CLKON”position.
2. Press and release CLOCK setpoint key.The follow-
ing program prompt message is displayed:
TODAY IS MON 10:30 PM 1/1/92
3. Press ADVANCE DAY / SCROLL key until the pro-
gram per day of week appears on the display.
4. Use Entry keys to enter proper time of day.
5. Press AM/PM key to change the AM to PM or vice
versa.
6. Use Entry keys to enter proper calendar date,
(MONTH/DAY/YR). Ifmonth anddayare singledigit
entries, precede the entry with “0”. For example,
02/04/88.
7. Press and release ENTER key.
PROGRAM MODE, SELECT SETPOINT
message is displayed.
FIG. 9 – KEYPAD – PROGRAMMING“CLOCK”
SETPOINT
LD00957
LD00958

YORKINTERNATIONAL 17
FORM 160.49-O2
To Enter DAILY SCHEDULE Setpoint:
(Refer to Fig.10.)
1. Press and release DAILY SCHEDULE setpoint key.
The following prompt message is displayed:
SUN START = XX:XX AM, STOP = XX:XX AM
2. If the displayed start and stop time is not the desired
schedule, enter the desired start and stop times as
follows:
a. Ifyoudo notwant thechiller toautomatically start
and stop on this day, press CANCEL key.
b. Use the Entry keys to enter desired hours and
minutes start time.
c. Ifnecessary, pressthe AM/PMkeytochange“AM”
to “PM” or vice versa.
d. Use the Entry keys to enter desired hours and
minutes stop time.
e. Ifnecessary,press theAM/PMkeytochange“AM”
to “PM” or vice versa.
3. Pressandrelease ADVANCEDAY/SCROLLkey.The
following prompt message is displayed:
MON START = XX:XX AM, STOP = XX:XX AM
4. Enter the desired start and stop time per Step 2.
5. Pressandrelease ADVANCEDAY/SCROLLkey.The
following prompt message is displayed:
REPEAT MON SCHEDULE MON-FRI? YES = 1; NO = 0
a. If you press the 1 Entry key, Monday’s start and
stop time will be automatically entered for Tues-
day through Friday.
– or –
b. If you press the 0 Entry key,Tuesday through Fri-
day can be programmed with different start and
stop times.
6. Use the ADVANCE DAY / SCROLL key with proce-
dure in Step 2. To enter start and stop times for
remainder of the week plus a holiday schedule if
required.
7. Press the ENTER key.
PROGRAM MODE, SELECT SETPOINT is displayed.
FIG. 10 – KEYPAD – PROGRAMMING “DAILY
SCHEDULE” SETPOINT
LD00959

18 YORK INTERNATIONAL
To Enter HOLIDAY Setpoint: (Refer to Fig.11.)
1. Press and release HOLIDAY setpoint key. The fol-
lowing program prompt message is displayed:
S_ M_ T_ W_ T_ F_ S_ HOLIDAY NOTED BY r
2. Press and release ADVANCE DAY/SCROLL key to
movecursor tothe day thatyouwish todesignate as
a holiday.
3. Press and release r entry key. An r will appear
next to the selected day.
4. After you have placed an r next to each of the days
that you wish to designate a holiday, press ENTER
key PROGRAM MODE, SELECT SETPOINT
message is displayed.
Tocancel allof thedesignated holidays: perform Step
1, press CANCEL key, and then press ENTER key.
PROGRAM MODE, SELECT SETPOINT
message is displayed.
To cancel one of the designated holidays: perform
Step 1, press ADVANCE DAY / SCROLL key until
the cursor appears to the right of the desired day,
press the r key, then press the ENTER key. FIG. 11 – KEYPAD – PROGRAMMING “HOLIDAY”
SETPOINT
To Enter REMOTE/ RESET TEMP RANGE Setpoint:
(Refer to Fig.12.)
1. Press andrelease REMOTE/RESET TEMP RANGE
setpointkey.The followingprogramprompt message
is displayed:
REMOTE TEMP SETPOINT RANGE = XX °F
2. Use Entry keys desired value (10 or 20).
3. Press and release ENTER key.
PROGRAM MODE, SELECT SETPOINT
message is displayed.
To Enter DATA LOGGER Setpoint:
Refer to Form 160.49-N7 for operation of this key.
FIG. 12 – KEYPAD – PROGRAMMING “REMOTE
RESET”TEMP RANGE
LD00961
LD00962

YORKINTERNATIONAL 19
FORM 160.49-O2
FIG. 13 – KEYPAD – SERVICE KEYS LOCATION
The Service keys are provided for the service techni-
cian’susewhen performingroutinemaintenanceorwhen
troubleshootingthe system.TheWARNINGRESET and
PRE-ROTATIONVANES keysare enabledin SERVICE
mode only.The remainder of the Service keys are en-
abled in SERVICE, LOCAL or REMOTE mode.
PRE-ROTATION VANES KEYS
If chiller is equipped with the REFRIGERANT LEVEL
CONTROL (and EPROM version C.02F(T).13 or later),
the pre-rotation vanes keys can be used to manually
control the refrigerant level variable orifice or the pre-
rotation vanes. The procedure to select either manual
vane or manual variable orifice control is contained in
“Special Setpoints and Programming Procedures”sec-
tion of Service manual, Form 160.49-M3 and must be
performed by a qualified service technician only.
OPEN – Press and release this key to drive the pre-
rotation vanes open.If the chiller is running,
SYSTEM RUN – VANES OPENING is displayed. If chiller is
not running, SYS READY TO START – VANES OPENING is
displayed. The vanes will continue to open until the
CLOSE, HOLD, or AUTO (if temperature error requires
it) keys are pressed and released.
HOLD – Press and release this key to hold the pre-
rotation vanes in their present position. If the chiller is
running, SYSTEM RUN – VANES HOLDING is displayed.
If chiller is not running,
SYS READY TO START – VANES HOLDING is displayed.The
vanes will remain stationary until the OPEN, HOLD, or
AUTO keys are pressed and released.
AUTO – Press andrelease this keytoput the pre-rota-
tion vanes under LCWT control as long as the current
limit setpoint is not reached, which causes the current
limit function to override the LCWT control. If system is
running, SYSTEM RUN – AUTO VANES is displayed. The
actual opening and closing of the vanes is indicated on
the display.When the vanes are opening,
SYSTEM RUN – VANES OPENING is displayed.If the vanes
are closing, SYSTEM RUN – VANES CLOSING is displayed.
WhenevertheControl Centeris inLOCAL,REMOTE or
PROGRAM mode,thevanecontrol circuitry isautomati-
cally placed in AUTO mode and the vanes operate to
control the leaving chilled water temperature to the pro-
grammed setpoint.
CLOSE – Press and release this key to drive the pre-
rotation vanes closed.If the chiller is running,
SYSTEM RUN – VANES CLOSING is displayed. If chiller is
not running, SYS READY TO START – VANES CLOSING is
displayed.When the vanes are full closed,
SYS READY TO START –VANES CLOSED is displayed. The
vanes will continue to close until the OPEN, HOLD, or
AUTO keys are pressed.
SERVICE KEYS
LD00963

20 YORK INTERNATIONAL
OTHER SERVICE KEYS
WARNING RESET – Press and release this key to re-
set any “WARNING” or “STATUS” message that can be
reset with this key, unless the condition still exists. To
reset any cycling or warning message, place the Con-
trol Center in SERVICE mode and press WARNING
RESET key. To reset any safety shutdown message,
press WARNING RESET key in SERVICE mode with
the COMPRESSOR switch in the STOP/RESET posi-
tion.
MANUAL OIL PUMP – This key is operational in any
mode. Press and release this key to run the oil pump.
Press and release the key again to stop the oil pump.A
10-minutemaximumis imposedon therunning ofthe oil
pump (i.e., the oil pump will automatically shut off after
10 minutes).If a longer running time is desired, the key
must be pressed again.The manual oil pump feature is
disabled during “START SEQUENCE INITIALIZED” to
allow for auto-zeroing of oil pressure transducers.
DISPLAY DATA – This key is operational in any three
of the Control Center modes of operation (SERVICE,
LOCAL or REMOTE). It is used to display certain sys-
tem operating parameters that are relevant to trouble-
shooting the chiller system.
Press and the DISPLAY DATA key.The following mes-
sages will sequentially scroll on the display. Each mes-
sage will be displayed for 2 seconds.
Messages 1 and 2 are only displayed if unit is equipped
with EPROM version C.02F(T).13 or later and Refriger-
ant Level Control has been enabled by a qualified ser-
vice technician using the “Special Setpoints and Pro-
gramming”procedures sectionof Service manual,Form
160.49-M3.
NO.1
MANUAL VANE OPERATION ALLOWED –Displayed when the
PRE-ROTATION VANES service keys have been se-
lected for manualVANE control.This allows these keys
tomanually controlthevanesin Service mode.Thepro-
cedure to select manual vanes control is in Service
manual,Form160.49-M3 andshouldbe performed only
by a qualified service technician.
– or –
NO.1
MANUAL LEVEL CONTROL ALLOWED –Displayed when the
PRE-ROTATION VANES keys have been selected for
manual REFRIGERANT LEVEL control. This allows
these keys to manually control the refrigerant level con-
trol variable orifice in Service mode.When manual re-
frigerant levelcontrol isselected, thepre-rotation vanes
Service keys cannot be used to control the vanes.The
procedure to select manual refrigerant level control is in
Service manual, Form 160.49-M3 and should be per-
formed only by a qualified service technician.
NO.2
PULLDN LEVEL = XXX%; SETP = XXX%; ACTUAL = XXX%
–Displayed when there is a refrigerant level setpoint
pulldown(ramp)in effect. PULLDN LEVEL isthe refrig-
erant level setpoint that is presently in effect. SETP is
therefrigerantlevelsetpoint thathas beenprogrammed
by theservicetechnician andACTUAL isthe refrigerant
level in the condenser. The pulldown period is 15 min-
utes in duration. During the pulldown period, a linearly
increasing ramp is applied to the level setpoint. This
causes the setpoint to increase from 0% to the pro-
grammedvalueoveraperiodof15minutes.After the15
minutes have elapsed, the setpoint remains the pro-
grammed value and this message is replaced by the
message ACTUAL = XXX%; LEVEL SETP = XXX% as
described below.
Arefrigerantlevelsetpointpulldownis putintoeffectwhen
thevanesare driven froma fullyclosedtoanopen posi-
tion, if the actual refrigerant level is less than the level
setpoint when the vane motor end switch (VMS) opens.
If the actual level is greater than the setpoint when the
VMS opens, the level is controlled to the programmed
setpoint.Whenever the vanes go to the fully closed po-
sition(VMS closed),anypulldownthat isin effectis can-
celled.
– or –
NO.2
ACTUAL LEVEL = XXX%; LEVEL SETP = XXX% –Displays
the actual refrigerant level in the condenser and the re-
frigerantlevel setpointprogrammedbythe service tech-
nician. This message replaces the previous message
after a refrigerant level setpoint pulldown period termi-
nates.
NO.3
SAT TEMPS EVAP = XX.X°F; COND = XX.X°F –This is the
refrigerantsaturationtemperaturesfortheevaporatorand
condenser.
NO.4
DISCHARGE TEMP = XXX.X°F; OIL TEMP = XXX.X°F
NO.5
HOP = XX.X PSIG; LOP = XX.X PSIG –This is the low oil
pressure (LOP) as measured at the oil sump and the
high oil pressure (HOP) as measured at the compres-
sor bearing input.