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FORM 150.60-NM3
65
YORK INTERNATIONAL
the internal clock. Default values will also be loaded into
memory for all setpoints and cut-outs. These may re-
quire reprogramming to assure they meet chiller op-
erating requirements. In addition, the low battery mes-
sage which is displayed for this condition will disappear.
NOTE: If a power failure should again occur, the above
process will again need to be repeated to bring
the chiller back on line.
In the unlikely event the low battery message should ever
appear, it will require the RTC Chip U13 on the Micropro-
cessor Board (Fig. 12) to be replaced. Care should be
taken to assure that the chip is properly installed. Pin 1
(dimple in the top of the chip) must be oriented as shown
(Fig. 12). The part number for the RTC Chip is
031-00955-000.
CRANKCASE HEATER
The crankcase heater for a compressor will be ON when-
ever the compressor is not running. The heater is inter-
locked into the compressor motor contactor and is not
controlled by the microprocessor.
The purpose of the crankcase heater is to prevent the
migration of refrigerant to the crankcase during shutdown
assuring proper lubrication of the compressor on
start-up.
Anytime power is removed from the chiller for more than
an hour, the crankcase heater should be left on for 24
hours prior to start. This can be accomplished by apply-
ing 115VAC to the control panel.
EVAPORATOR HEATER
The evaporator heater prevents water standing in the
evaporator from freezing. Whenever outdoor ambient
temperature drops below 40°F, the microprocessor will
turn the evaporator ON. If temperature rises above 45°F,
the heater will be turned off.
METRIC DISPLAY
The control panel is capable of providing displays of pres-
sure and temperature in metric values. Temperatures will
be displayed in °C and pressures in kPa.
A Metric to English temperature conversion table is pro-
vided inside the rear cover of this manual. Pressure can
be converted from PSI to kPa using the formula PSI x
6.89 = kPa.
To obtain panel displays in metric, Switch 5 of Dip
Switch S1 on the Microprocessor Board must be placed
in the OPEN position (Page 28). The positioning of this
switch can then be verified by pushing the OPTIONS key
and verifying that METRIC UNITS READOUT is pro-
grammed (Page 26).
EMS/BAS CONTROLS
The microprocessor is capable of REMOTE START/
STOP, REMOTE UNLOADING (Pulldown demand limit-
ing), and REMOTE SETPOINT RESET. These functions
can be easily utilized by connecting use supplied dry
contacts to the Microprocessor Board.
REMOTE START/STOP BY A CYCLING DEVICE
OR TIME CLOCK
Remote START/STOP is accomplished by connecting a
time clock or other dry contact in series with the flow
switch on terminals 13 & 14. See Fig.11 for the location
of the terminals. The contact must be closed to allow the
chiller to run. Any time the contact opens, the chiller will
shut down and the following status message will be dis-
played.
Wiring from these contacts should not exceed 25 ft. and
should be run in grounded conduit that does not carry
any wiring other than control wiring. Additionally, if an
inductive device (relay, contactor) is supplying these
contacts, the coil of the device must be suppressed with
a user supplied YORK P/N 031-00808 suppressor.
REMOTE SETPOINT RESET
(REMOTE RESET TEMP RANGE)
Remote Setpoint Reset allows resetting the setpoint up-
ward from the programmed value in memory. This is ac-
complished by connecting a dry contact between ter-
minals 13 & 17. See Fig. 11 for the location of these
terminals. Closing the contact for a defined period of time
allows reset of the setpoint upward by up to 40°F above
the setpoint programmed in memory.
The maximum desired reset must be programmed into
memory and can be a value of 02 to 40°F. This value will
vary according to the users requirements. To program
the reset, press the REMOTE SETPOINT TEMP
RANGE key. The following message will appear.
The display will indicate the REM SETPOINT which is
always equal to the chilled liquid setpoint plus the offset
from the reset signal. The display will also show the
REM RANGE which is the same as the maximum reset
required. Key in the maximum reset for the REM
S Y S # 1
N O
R U N
P E R M
S Y S # 2
N O
R U N
P E R M
R E M
S E T P O I N T
=
4 0 . 0
R E M
R A N G E
=
2 0
D E G F
Содержание YCAJ44HE8
Страница 16: ...16 YORK INTERNATIONAL WIRING DIAGRAMS LD02165 FIG 5 ELEMENTARY DIAGRAM...
Страница 17: ...FORM 150 60 NM3 17 YORK INTERNATIONAL FIG 5 ELEMENTARY DIAGRAM Cont d LD02166...
Страница 20: ...20 YORK INTERNATIONAL CONNECTION DIAGRAM ELECTRICAL BOX FIG 7 CONNECTION DIAGRAM LD02171...
Страница 21: ...FORM 150 60 NM3 21 YORK INTERNATIONAL FIG 7 CONNECTION DIAGRAM Cont d LD02172...