Lennox Prodigy 2.0 User Manual

Page 51
EXAMPLE: The application calls for the discharge air occupied set point Parameter 180 to be 55.0°F when Return Air
Temperature is 70.0°F or higher. When the Return Air Temperature drops below 70°F, the set point needs to increase
proportionately with the Outdoor Air Temperature decrease (maximum set point increase of 10°F). The 10.0°F Return Air
Temperature difference is called Parameter 203 and the set point increase of 10.0°F is called the Parameter 204. See figure
15.
DACC RAT RS ADJ BND
Parameter 204
Example 10.0°F
DACC RAT RS PRP BND
Parameter 206
Example 10.0°F
Reset Set point Approx.60.0°F (at 65.0°F RAT)
55.0°F
65.0°
F
60.0°F Return
Air Temp.
Parameter 205 (DACC RAT RS ADJ SP)
70.0°F
Discharge Air Cooling Control or Free
Cooling Set point
Figure 15. Return Air Reset Example
To use example values, set the following parameters:
 Parameter 205 – Set to 70.0°F
 Parameter 206 – Set to 10.0°F
 Parameter 204 – Set to 10.0°F (this setting enables Discharge Air Control Cooling return air reset).
10.1.3. Discharge Air Control Cooling (DACC) Total Reset Limit
Parameter 207 with a default setting of 10.0°F defines the total Discharge Air Control Cooling set point reset limit. This total
limit is the sum of both return and outdoor Discharge Air Control Cooling resets. This parameter limits total DACC_SP
adjustment band and overrides the adjustment bands for Parameter 201 and Parameter 204 if necessary.
Table 42. Discharge Air Cooling Parameters Summary
Control Parameter Control Value Unit Description
No. Screen Name
Short
Description
Min. Default Max. Unit Description
111 COOL STAGING OPTION
Cooling Sta
ging Option
0
Check unit
parameter
label as default
may be altered
at factory test.
4 Option
Cooling staging options:
0- No cooling operation
1- Wired thermostat operation, Two cooling
stages and units with Economizers
Y1 = Free Cooling,
Y2 = Adds all mechanical stages.
2- Wired thermostat operation. Two cooling
stages and Units with Economizers
Y1=Free Cooling
Y2= adds first stage of mechanic
al.
3- Wired thermostat operation. Three cool
ing stages.
Y1 only = first stage,
Y2 only = second stage,
Y1+Y2 = third stage.
Units with Economizers Y2 only
adds first stage of mechanical,
Y1+Y2 adds first and second stage
of mechanical.
4- Discharge air control. Up to four stages.
180 DACC OCC SETPOINT
Discharge
Air Control
Cooling Oc
cupied Set
Point
40.0 55.0 80.0 °F
Discharge Air Control Cooling set point during
occupied period.

Lennox Prodigy 2.0 Specifications

General

Brand	Lennox
Model	Prodigy 2.0
Category	Controller
Language	English