R E M 0 T E L E A V I N G
W A T E R T E M P C O N T R O L
This message indicates that the cooling setpoint is un- der REMOTE control. When under remote control, the cooling setpoint will be determined by a remote device such as an ISN control. The message also indicates that the control point is based on LEAVING water tem- perature out of the evaporator.
R E M O T E R E T U R N
W A T E R T E M P C O N T R O L
This message indicates that the cooling setpoint is un- der REMOTE control. When under remote control, the cooling setpoint will be determined by a remote device such as an ISN control. This message also indicates that the control point is based on RETURN water tem- perature into the evaporator.
Immediately after the control mode message is dis- played, the COOLING SETPOINT entry screen will be displayed. If the unit is programmed for LEAVING liquid control the following message will be displayed:
S E T P O | I N T | = | 4 | 5 . 0 ° F |
R A N G E = | +/- | 2 | . 0 ° F | |
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(leaving chilled water control)
The above message shows the current chilled water tem- perature SETPOINT at 45.0°F (notice the cursor posi- tioned under the number 5). Pressing either the UP or DOWN arrow will change the setpoint in .5°F increments.
FORM
After using the UP and DOWN arrows to adjust to the desired setpoint, the ENTER/ADV key must be pressed to enter this number into memory and advance to the
RANGE SETPOINT.
This will be indicated by the cursor moving under the current RANGE setpoint. The UP and DOWN arrow keys are used to set the RANGE, in .5 °F increments, to the desired RANGE setpoint. After adjusting the setpoint, the ENTER/ADV key must be pressed to enter the data into memory.
Notice that the RANGE was programmed for +/- 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 previous message.
S E T P O | I N T | = | 4 | 5 | . | 0 | ° F |
R A N G E | = | + 2 | . | 0 | ° F | ||
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(return chilled liquid control)
Notice that the range no longer has a +/- X.X °F, but only a + X.X °F RANGE setpoint. This indicates that the setpoint is not centered within the RANGE but could be described as the bottom of the control range A listing of the limits and the programmable values for the COOL- ING SETPOINTS are shown in Table 27.
The SETPOINT and RANGE displays just described were based on LOCAL control. If the unit was pro- grammed for REMOTE control (under the OPTIONS key), the above programmed setpoints would have no effect.
Both LEAVING and RETURN control are described in detail under the section on Capacity Control.
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YORK INTERNATIONAL | 75 |
