26 YORK INTERNATIONAL
FIG. 18 – WATER COOLING RANGE SELECT
(SET FOR ± 2.0°F CONTROL)
SINGLE CIRCUIT UNITS
WATER COOLING RANGE CODE
0 3.4°C
1 3.9°C
2 4.4°C
3 5.0°C
4 5.6°C
5 6.1°C
6 6.7°C
7 7.8°C
RETURN WATER TEMPERATURE CONTROL
Follow the steps below to set up the panel switches prior
to operating the chiller. Setpoints of –9.9° to 9.9°C can
be programmed in to the panel if the Micro Logic Board
is equipped with a GEII.4M REV.1 EPROM (Fig. 26).
A. Before any control panel switches are set, SW3 (Fig.
26), on the Micro Logic Board must be placed in the
OFF position for RWT control.
B. Determine what the desired RWT must be and fill in
the blanks below:
1. Design RWT Setpoint = .
2. *Design Cooling Range = .
(Temp. difference across cooler)
*Select from those listed below. These are also listed on the con-
trol panel.
C. Subtract the Cooling Range from the RWT Setpoint:
i.e.:Design RWT Setpoint: 12.7°C
Design Cooling Range: –5.6°C
7.1°C
Computed Setpoint
D. Determine whether the “Computed Setpoint” falls into
the temperature range of –9.9°C to 0°C or 0° to 9.9°C.
1. If the “Computed Setpoint” falls into the tempera-
ture range from –9.9° to 0°C, place SW1 on the
Micro Logic Board to the OFF position (see Page
32). This places an imaginary minus sign into the
micro’s memory in front of the setpoint dialed for
the setpoint switches.
2. If the ”Computed Setpoint” falls into the tempera-
ture range from 0 to 9.9°C, place SW1 on the Mi-
cro Logic Board to the ON position (see page 32.)
E. Place the two Setpoint Switches to the “Computed
Setpoint”. (See Fig. 19.)
i.e.: 7,1 = 7.1°C from Step C if SW1 on the Micro
Logic Board is ON (Step C).
CHILLED WATER TEMPERATURE SET-POINT AND COOLING RANGE SELECTION
METRIC ONLY
CAUTION: Selection of the Cooling Range should be
made according to the deviation from set-
point which can be tolerated and whether
more than normal system cycling of the load-
ers and compressor is experienced due to a
cooling range which is too tight (small). Code
7,
±
2.0°F is recommended.
System Loading & Unloading
See pages 29 & 30 for loading and unloading points for
both return and leaving water temperature control.
2
LD01857
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