FORM 201.10-NM4
113
YORK INTERNATIONAL
MISSIONING THE CHILLER. FAILURE TO
PROPERLY PROGRAM THESE VALUES MAY
CAUSE DAMAGE TO THE CHILLER OR OP-
ERATING PROBLEMS.
8.2 PROGRAM KEY
USER PROGRAMMABLE VALUES
Refrigerant Type
The Refrigerant Type value is used to program the chiller
for the type of refrigerant and is password protected.
This value MUST be programmed correctly. Failure to
do so may cause serious damage to the chiller. The
type of refrigerant used on individual models is noted in
the Engineering Data stamped on the chiller nameplate.
To program for R22, key in 022. To program for R134a
key in 134. Press the Enter key to store the pro-
grammed value into memory.
NOTE: The type of refrigerant programmed must match
the refrigerant selected on the SW1 Dip Switch
on the Microprocessor Board. These selections
can be viewed by pressing the Options key (see
Section 3.7). If these two selections do not match,
the following message will appear:
The chiller will not operate until this situation is
corrected.
High Discharge Pressure Cutout
The Discharge Pressure Cutout is a microprocessor
backup for the mechanical high pressure cutout located
in each refrigerant circuit. This safety is bypassed for the
first 5 seconds of operation after which if the cutout point
is exceeded for 3 seconds, the system will shut down.
Normally air-cooled chillers such as YCAS/YDAS chill-
ers should have the cutout set at 395 PSIG for R22
models and 275 PSIG for R134a models. The micro
will, however, accept values between 200 - 399 PSIG
for R22 models and between 128 - 275 PSIG for R134a
models. For this cutout to be functional, the Discharge
Pressure Read-out Option must be installed (fitted as
standard on 50 Hz models). This programmable value
is password protected.
To program the Discharge Pressure Cutout, key in the
desired value and press the Enter key to store the value
into memory and scroll to the next display.
Low Ambient Temperature Cutout
The Low Ambient Cutout is used to select the ambient
temperature below which the chiller may not operate. If
the ambient temperature falls 1°F below this point, the
chiller will shut down. Restart will occur automatically,
when temperature rises more than 1°F above the cut-
out and cooling demand is present (see also Section
2.4). This programmable value is password protected.
If the SW1 Dip Switch on the Microprocessor Board is
set for Standard Ambient Control (see Section 3.7)
the low ambient cutout is set at 25°F and is NOT pro-
grammable. If the Dip Switch is set for Low Ambient
Control, programming of the cutout between 00.0° -
50.0°F is allowed. This allows higher values than 25°F
to be programmed to shut down the chiller when other
cooling methods become operational. Values below
25°F can be used for applications requiring chiller op-
eration at lower temperatures. If operation is occasion-
ally needed below 1°F, the cutout should be set at 00.0°F.
This will allow operation at any temperature as the mi-
cro will only recognize temperatures above 1°F. Tem-
peratures below 1°F will not be displayed.
To program the Low Ambient Cutout, key in the required
setting and press the Enter key to store the value into
memory and scroll to the next display.
NOTE: Operation below 1°F may occasionally cause
nuisance low pressure safety shutdowns. This
will not cause a problem provided ambient tem-
perature is not expected to be below 1°F for
more than a short time.
High Ambient Temperature Cutout
The High Ambient Cutout is used to select the ambient
temperature above which the chiller may not operate. If
the ambient temperature rises 1°F above this point, the
chiller will shut down. Restart will occur automatically, when
temperature falls more than 1°F below the cutout and cool-
ing demand is present.
This cutout is normally set at 130°F to allow operation to
the absolute maximum temperature capability of the elec-
tromechanical components, however, values between
100.0 - 130.0°F are accepted. This programmable value
is password protected.
To program the High Ambient Cutout, key in the required
setting and press the Enter key to store the value into
memory and scroll to the next display.
R E F R I G E R A N T
T Y P E
2 2
O R
1 3 4
2 2
R E P R O G R A M
T Y P E
O F
R E F R I G E R A N T
T O
R U N
D I S C H A R G E
P R E S S U R E
C U T O U T
=
3 9 5 . 0
P S I G
L O W
A M B I E N T
T E M P
C U T O U T
=
2 5 . 0 ° F
H I G H
A M B I E N T
T E M P
C U T O U T
=
1 3 0 . 0 ° F
