Specifications

22 YORK INTERNATIONAL
SYSTEM RUN – LOW PRESSURE LIMIT IN EFFECT
Displayed when the chiller is running and the evapora-
tor pressure falls to 5.55 PSIA (R11); 4.50 PSIA (R123).
Simultaneously, the prerotation vanes will be prevented
from further opening. This action maintains chiller opera-
tion to prevent low-evaporator-pressure shutdown at 5.42
PSIA (R11); 4.40 PSIA (R123). When the evaporator
pressure rises to 5.65 PSIA (R11); 4.70 PSIA (R123),
the vanes will be permitted to open. Low pressure limit
feature is not used when program jumper (JP-3) is cut
(Brine application).
SYSTEM RUN – HIGH PRESSURE LIMIT IN EFFECT
Displayed when the chiller is running and the condenser
pressure rises to 28.8 PSIA. Simultaneously, the prero-
tation vanes will be inhibited from further opening. This
action occurs to prevent system shutdown on high con-
denser pressure at 29.7 PSIA. When the condenser
pressure falls to 28.6 PSIA, the vanes will be permitted
to open.
SYSTEM RUN – PRESS STATUS
Displayed when the chiller is running. It instructs the
operator to press the “STATUS” key, whereupon the fol-
lowing message will be displayed. The following “Warn-
ing Messages” are displayed alternately with the fore-
ground message. The foreground message is displayed
for 2 seconds, then the warning message is displayed
for 2 seconds, etc. It is not necessary to press the “STA-
TUS” key.
WARNING: COND OR EVAP TRANSDUCER ERROR
Indicates a probable condenser or evaporator transducer
problem, because the output is unreasonable. The mi-
croprocessor arrives at this conclulsion by subtracting
the evaporator transducer output from the condenser
transducer output. The result must be zero or some posi-
tive number. If the result is a negative number, it con-
cludes that there is a probable condenser or evaporator
transducer problem. This function is inhibited for the first
10 minutes of chiller run-time, and is checked every 10
minutes thereafter. Message is reset by pressing the
“WARNING RESET” key in the “SERVICE” mode.
WARNING: PURGE FLOAT SWITCH ERROR
Indicates the microprocessor is receiving conflicting digi-
tal signals from purge top float switch and purge bottom
float switch (i.e., liquid is simultaneously above TFS and
below BFS . . . an impossible condition). Message is
reset by pressing “WARNING RESET” key in the “Ser-
vice” mode.
Therefore:
(100%) (50% x 200) = 100A = Vanes stop opening
(104%) (50% x 200) = 104A = Vanes driven toward
close position
SYSTEM RUN – AUTO VANES
Displayed when the chiller is running, the MicroComputer
Control Center is in “SERVICE” mode, and the vanes
are operating in “AUTO” mode.
SYSTEM RUN – VANES OPENING
Displayed when the chiller is running and the Micro-
Computer Control Center is in “SERVICE” mode with:
• The vanes operating in “AUTO” mode and opening to
maintain the leaving chilled water temperature
setpoint.
-or-
• The operator has pressed the vanes “OPEN” key on
the keypad.
SYSTEM RUN – VANES CLOSING
Displayed when the chiller is running and the Micro-
Computer Control Center is in “SERVICE” mode with:
• The vanes operating in “AUTO” mode and closing to
maintain the leaving chilled water temperature
setpoint.
-or-
• The operator has pressed the vanes “CLOSE” key on
the keypad.
SYSTEM RUN – VANES HOLDING
Displayed when the chiller is running, the Micro-
Computer Control Center is in “SERVICE” mode, and
the operator has pressed the vanes “HOLD” key.
SYS READY TO START – VANES OPENING
Displayed when the chiller is not running and the opera-
tor has pressed the vanes “OPEN” key on the keypad.
SYS READY TO START – VANES CLOSING
Displayed when the chiller is not running and the opera-
tor has pressed the vanes “CLOSE” key on the keypad.
SYS READY TO START – VANES HOLDING
Displayed when the chiller is not running and the opera-
tor has pressed the vanes “HOLD” key on the keypad.