Lennox PRODIGY M2 User Manual

10. Discharge Air Control
Page 45
PRODIGYT M2 UNIT CONTROLLER
Control Parameter
No. Name
DescriptionUnits
Control Value
Min. Default Max
8.06
DACC_OAT_
RS_ Proportion-
al_ Band.
1
1
31
20
94
60
Counts
O:DegF
Discharge Air Control Cooling outdoor ambient temperature cooling proportional
band. Also used to reset free cooling setpoint (6.23).
8.07
DACC_OAT_
RS_ Adjust_
Band
0
0
0
0
47
30
Counts
O:DegF
Discharge Air Control Cooling outdoor temperature ambient cooling adjustment
reset band. 0 disables outdoor air cooling reset. Also used to reset free cooling
setpoint (6.23).
10.5. Heating
The discharge air control heating (DACH) option automatically cycles up to 4 stages of heating to maintain a discharge air
control heating setpoint (DACH_SP).
DACH option applies to gas/electric and electric /electric units only; DACH is not allowed with heat pumps units.
Refer to figure 23 for DACH heating stages.
Adjust ECTO 5.09 to option 1 to enable discharge air control.
IMPORTANT − Discharge air sensor RT6 must be moved to the supply air duct, preferably after a 90 degree branch off of the
main duct.
DACH is initiated by an input in one of three ways:
1. W1 input from an external deviceECTO 6.01 must be set to 0, local thermostat mode.
2. Heating demand while in zone sensor modeECTO 6.01 must be set to 1, 2, or 3.
3. L Connection network commandECTO 6.01 must be set to 4, 5, 6 or 7.
110
111
112
113
114
115
109
108
107
110°F Default Occupied DACH Setpoint
H1
ON
OFF
110°F + 5°F
ECTO 7.10 + 7.12
7.11 Unoccupied DACH_SP is adjusted
7.13 DACH Stage−Up Delay 3 minutes
7.14 DACH Stage−Down Delay 2 minutes
Compressor Minimum Run Times Apply
106
105
104
5°F DACH Deadband
(All Stages Same Setting)
H2
ON
OFF
110°F − 2°F Diff
ECTO 7.10 − 7.15
ON
OFF
H4
ON
OFF
H3
110°F − (2°F Diff X 2)
110°F − (2°F Diff X 3)
ECTO 7.10 − ( 7.15 X 3)
ECTO 7.12
ECTO 7.10
ECTO 7.10 − (7.15 X 2)
H1=Heating Stage 1
H2=Heating Stage 2
H3=Heating Stage 3
H4=Heating Stage 4
Note − MGV units control discharge
air by modulating gas valves.
Figure 23. Discharge Air Control Heating (DACH) Stages − Default Values Shown
10.6. Outdoor Air Reset
The DACH setpoint can be automatically reset when outdoor air temperature becomes warmer.
For outdoor air based DACH setpoint reset, the discharge air control heating setpoint starts to decrease when the outdoor air
temperature (OAT) rises to the DACH_OAT_RS_SP (ECTO 8.12) (default 40°F). The reset setpoint will continue to de-
crease at the rate equal to the DACH_OAT_RS_Adjustment_Band (ECTO 8.14) divided by the DACH_OAT_RS_Propor-
tional_Band (ECTO 8.13). See the following example:

Lennox PRODIGY M2 Specifications

General

Brand	Lennox
Model	PRODIGY M2
Category	Controller
Language	English