McQuay OM 751
27
Description of Operation
Remote Wall-Mounted Sensor with +/–3°F
Adjustment (optional)
When the optional remote wall-mounted sensor with +/–3°F adjustment dial is used, the UVC
effectively writes the value of the set point adjustment dial to the Set Point Offset Input
variable.
Note –
If a network connection is used to adjust the Set Point Offset Input variable, you must not
use the optional remote wall-mounted sensor with +/–3°F adjustment.
–
If the keypad/display is used by room occupants to adjust the Set Point Offset, do not use
the optional remote wall-mounted sensor with +/–3°F adjustment.
If you have the optional remote wall-mounted sensor with +/–3°F adjustment and an
occupant uses the keypad to make Set Point Offset adjustments, this overrides any
+/–3°F adjustment on the optional remote wall-mounted sensor since the keypad/display
has higher priority. If you find that changes to the +/–3°F adjustment on the remote wall-
mounted sensor have no effect, it is likely that an occupant used the keypad/display to
make a Set Point Offset change. Cycle unit power to clear this situation and restore the
ability to change the Set Point Offset from the +/–3°F adjustment on the remote
wall-mounted sensor.
Remote Wall-Mounted Sensor with 55°F to 85°F
Adjustment (optional)
When the optional remote wall-mounted sensor with 55°F to 85°F adjustment dial is used, the
UVC will effectively write the value of the set point dial to the Space Temp Set Point Input
variable.
Note –
If a network connection is using the Space Temp Set Point Input variable, do not use the
optional remote wall-mounted sensor with 55°F to 85°F adjustment.
–
If it is intended that the LUI will be used by room occupants to adjust the Setpoint Offset,
then you must not use the optional remote wall-mounted sensor with 55
°
F to 85
°
F
adjustment. When using the optional remote wall-mounted sensor with 55
°
F to 85
°
F
adjustment, the UVC will ignore any Setpoint Offset changes made at the LUI.
Effective Set Point Calculations
The UVC calculates the effective set point (Effective Set Point Output) based on several
factors. These factors include the six occupancy set points for heating and cooling (Occupancy
Temperature Set Point), occupancy mode, the value of the network variables Space Temp Set
Point Input, Set Point Offset Input, and the Set Point Shift Input as well as the optional wall-
mounted sensor’s set point adjustment knob. As always, network inputs have priority over
hardwired connections.
The UVC determines if heating or cooling is required based on the current unit mode (Heat/
Cool Mode Output) and then calculates the required set point for heating or cooling. After
calculating, the Effective Set Point Output network variable is set equal to the calculated set
point. The Effective Set Point Output is the temperature set point that the UVC maintains,
which normally appears on the keypad/display.
