Reznor FX05 User Manual

Form CP-MAPS-D12 with FX05, P/N 209341 Rev 4, Page 7
Discharge
Air Setpoint
Outside Air
Temperature
dHL = 70ºF oH2 = 60ºF
dHH = 78ºF oH3 = 30ºF
Variable
Name
Description
Default Value
(Range)
dHL
Standard Discharge Air Setpoint (Primary Setpoint)
dHL is the value of the discharge air heating setpoint when
the outside air temperature is at its warmest value to allow
minimum heating. The discharge air temperature will not
change to a lower value than dHL regardless of the out-
side air temperature. If the reset option is disabled, the dHL
becomes the primary neutral air heat discharge air setpoint.
70ºF
(50 - 115ºF)
dHH
Outdoor Air Reset Option
dHH is the value of the discharge air heating setpoint when
the outside air temperature is at its coldest value to allow
maximum heating. The discharge air temperature will not
change to a higher value than dHH regardless of the outside
air temperature. The default value disables the option.
78ºF
(45 - 120ºF)
oH2
Outdoor Reset Dry Bulb Heating – High Setting
The value of the outside air temperature corresponding to
the dHL low heating setpoint value.
60ºF
(20 - 70ºF)
oH3
Outdoor Reset Dry Bulb Heating – Low Setting
The value of the outside air temperature corresponding to
the dHH high heating setpoint value.
30ºF
(-40 - 65ºF)
Disable
Making the dHH value lower than the dHL value disables this
functionality.
Disabled
Autom atic Changing of the Discharge Air
Setpoint Based Upon Outside Air
Tem perature
68.0 º F
70.0 º F
72.0 º F
74.0 º F
76.0 º F
78.0 º F
80.0 º F
30 ºF 40 ºF 50 ºF 60 ºF
Outside air Temperature
Discharge Air
Temperature
(example 78ºF). Therefore, when the outside air is 60ºF, the unit can deliver
70ºF neutral air. And, when the outside air temperature drops to 30ºF, the unit
can provide 78ºF neutral air. The higher neutral air setpoint provides neutral air
matching the space temperature, thus better comfort control.
Heat Staging
Upon a call for heat, to maintain the active discharge air setpoint, the unit will
enable a stage when the discharge air temperature is more than ½ of the heat-
ing proportional band (HPP) below the setpoint. Default HPP value is 10ºF.
Example: Active setpoint = 70ºF. A stage is enabled when the discharge
air temperature (dAt) is less then 65ºF. Likewise, if the discharge air tem-
perature is above 75ºF, an active stage of heating is turned OFF.
If the discharge air temperature rises above ½ HPP value above the setpoint
(70ºF + 5ºF = 75ºF) after initially starting, the 1st stage will remain ON for 180
seconds then turn OFF.
FIGURE 4 - Outside
Air Reset (dHH) allows
automatic changing
of discharge air
temperature based on
outside air temperature.

Reznor FX05 Specifications

General

Brand	Reznor
Model	FX05
Category	Computer Hardware
Language	English