Reznor RXH (Outdoor PreevA) Unit Installation Manual - Manual (Page 54)

Form I-RDH/REH/RHH/RXH (12-14), Page 54
Fan Operation
When the slide is not in the OFF position and the unit is in the Occupied Mode based
upon the input, the fan will run continuously. In the Unoccupied Mode, the fan will
only run on a call for heating or cooling. The fan will be off if the slide is in the OFF
mode. Upon a call for the fan to run, if the air proving switch does not make after 180
seconds, the unit shuts down. Turn the unit FX05 controller OFF then ON, or press
the UP and Down arrows simultaneously for 5 seconds, to reset the alarm condition.
When the unit is locked out, heating and cooling functions will be disabled. Control will
display a flashing “AP”.
If cooling or heating operations are energized and fan proof is lost for three seconds,
the cooling or heating functions will be shut down, fan will be de-energized, and “AP”
will flash on the display.
In the unoccupied mode, when the slider switch is moved to the OFF position, or the
call for heating or cooling ends, the fan will run for an additional 30 seconds before
shutting off. This fan delay time is adjustable using variable “Fod”.
Occupied Mode
Unit will control to the Occupied Setpoints.
Cooling or Heating Slider Mode & Dial Setpoint (Options DG1 and DG2): The
dial setting is the working heating or cooling setpoint.
Auto Slider Mode & Dial Setpoint (Options DG1 and DG2): The dial setting is
the midpoint for the working heating and cooling setpoint. The actual setpoint
is adjusted by a value of “db” (deadband) which has a default value of 2°F.
The cooling setpoint = dial setting + db = 72°F + 2°F = 74°F
The heating setpoint = dial setting + db = 72°F - 2°F = 70°F
Auto, Cooling, or Heating Slider Mode, & Warmer/Cooler Dial (Options DG5
and DG6): The value HSP or CSP in the controller becomes the active heat-
ing and cooling setpoint basis. The warmer/cooler adjusts the setpoint by
± 6°F.
“HSP,” default 68°F
“CSP,” default 72°F
The cooling setpoint = dial setting + CSP = +6°F + 72°F = 78°F
The cooling setpoint = dial setting + CSP = -6°F + 72°F = 66°F
The heating setpoint = dial setting + HSP = +6°F + 68°F = 74°F
The heating setpoint = dial setting + HSP = -6°F + 68°F = 62°F
Note: When variable SSI = ON, Room Command Module with setpoint scale
should be used (DG1 or DG2). When SSI = OFF, Room Command Module with
warmer/cooler scale should be used (DG5 or DG6).
Unoccupied Mode
Unit will control to the Unoccupied Temperature Setpoints. The unoccupied setpoints
are the working Heating Setpoint minus the value of “UoU” which has a default of 10°F
and the working Cooling Setpoint plus the value of “UoU”.
Auto Slider Mode & Dial Setpoint (Options DG1 and DG2):
The cooling setpoint = dial setting + db + UoU = 72°F + 2°F + 10°F = 84°F
Boost Mode: Unit will add an adjustable amount BOU (nciBoostModeOffset)
(default 5°F) to the working heating setpoint and subtract from the working
cooling setpoint. Boost Mode will only operate in Heating Only or Cooling Only
modes. Boost is not available in Auto Mode.
Example: Cooling Slider Mode & Dial Setpoint:
The cooling setpoint = dial setting + BOU = 72°F - 5°F = 67°F
Heating Operation - The unit will initiate heating if the temperature sensed at the
space sensor or discharge falls below the “HSP” setpoint by the value of the heating
proportional band, “HPB” (Default value 5°F). When it does, full heating turns on
8.0 Controls and
Operation
(cont’d)
8.3 Digital Controls for
RDH, REH, RHH,
and RXH (cont’d)
8.3.1 Optional Digital Heating/Cooling/Makeup Air Controls, Options
DG1, DG2, DG5, DG6 - Model RDH only (cont’d)