Table 13 - Cooling Setpoints, Programmable Limits And Defaults; Return Chilled Liquid Control - York YCAL0019 Installation, Operation And Maintenance Manual

FORM 150.67-NM1
ISSUE DATE: 4/28/2017
Notice that the RANGE was programmed for plus or
minus X.X° F. This indicates the SETPOINT to be in
the center of the control range. If the control mode has
been programmed for RETURN LIQUID control, the
message below would be displayed in place of the pre-
vious message.
When in leaving chilled liquid temperature control,
the microprocessor will attempt to control the leaving
water temperature within the temperature range of the
setpoint plus or minus the range. In the above example,
control will be in the range of 43 to 47 °F.

Return Chilled Liquid Control

S E T P O I N T =
R A N G E =
In return chilled liquid control, the range no longer has
a plus or minus X.X °F, but only a plus X.X °F RANGE
setpoint. This indicates that the setpoint is not centered
within the RANGE but could be described as the bot-
tom of the control range. A listing of the limits and the
programmable values for the COOLING SETPOINTS
are shown in Table 13.
The SETPOINT and RANGE displays just described were
based on LOCAL control. If the unit was programmed for
REMOTE control (under the OPTIONS key), the above
programmed setpoints would have no effect.

TABLE 13 - COOLING SETPOINTS, PROGRAMMABLE LIMITS AND DEFAULTS

SETPOINT KEY
LEAVING CHILLED LIQUID SETPOINT
LEAVING CHILLED LIQUID CONTROL RANGE
RETURNED CHILLED LIQUID SETPOINT
RETURN CHILLED LIQUID CONTROL RANGE
MAX EMS-PWM REMOTE TEMPERATURE RESET
* Refer to Engineering Guide for operation below 30°F (-1.1°C). Alternate thermal expansion valves must be used below 30°F (-1.1°C).
* When using glycol, Leaving Chilled Liquid Setpoint should not be set below 20°F (-6.7°C).
** Do not exceed 55°F (12.8°C) setpoint before contacting the nearest Johnson Controls Office for application guidelines.
JOHNSON CONTROLS
4 5 . 0 ° F
+ 1 0 . 0 ° F
WATER COOLING
GLYCOL COOLING
WATER COOLING *
GLYCOL COOLING *
When in return chilled liquid temperature control, the
microprocessor will turn all compressors OFF at set-
point and will turn compressors on as return chilled
liquid temperature rises. All compressors will be ON
at setpoint plus the range. If the range equals the tem-
perature drop across the evaporator when fully loaded,
the leaving chilled liquid temperature will remain near
the setpoint plus or minus a few degrees as the chiller
loads and unloads according to return chilled liquid
temperature.
Both LEAVING and RETURN control are described in
detail under the section on Capacity Control.
Remote Setpoint Control
Pressing the COOLING SETPOINTS key a second
time will display the remote setpoint and cooling
range. This display automatically updates about every
2 seconds. Notice that these setpoints are not "locally"
programmable, but are controlled by a remote device
such as an ISN control, remote reset option board, or
remote PWM signal. These setpoints would only be
valid if the unit was operating in the REMOTE mode.
The following messages illustrate both leaving chilled liq-
uid control and return chilled liquid control respectively.
R E M S E T P
R A N G E =
(leaving chilled liquid control)
MODE LOW LIMIT
40.0°F
4.4°C
*10.0°F
-12.2°C
1.5°F
—
0.8°C
40.0°F
4.4°C
10.0°F
-12.2°C
— 4.0°F
2.2°C
2°F
—
1.0°C
SECTION 7 – UNIT CONTROLS
= 4 4 . 0 ° F
+ / - 2 . 0 ° F
HIGH LIMIT DEFAULT
**70.0°F 44.0°F
21.1°C 6.7°C
**70.0°F 44.0°F
21.1°C 6.7°C
2.5°F 2.0°F
1.4°C 1.1°C
70.0°F 44.0°F
21.1°C 6.7°C
70.0°F 44.0°F
21.1°C 6.7°C
20.0°F 10.0°F
11.1°C 5.6°C
40°F 20°F
22.0°C 11.0°C
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