Lennox Prodigy 2.0 Application Manual page 46

9.3.3. Variable Frequency Drive Control
The M3 Unit Controller is only compatible with the factory installed variable frequency drives used to control the supply
blower. The analog control for the variable frequency drives is 0­10VDC. This manual uses percent (%) for all blower and fan
speeds. For example, 50% blower speed equals 30Hz equals 5VDC. Output frequency to the motor is displayed on the VFD
drive 7 segment LEDs.
Speed %
30
40
50
60
70
80
90
100
9.4. Supply Constant Air Volume (CAV) with Zone Bypass Damper Control
Configuration ID 2 position 7 must be set to Y to enable Prodigy 2.0 Zone bypass operation with Constant Air Volume.
This configuration is used for L Connection or third-party zoning systems that utilize a blower bypass damper for controlling
duct static pressure. The M3 Unit Controller controls duct static pressure by reading the duct pressure and varying the
bypass damper position between minimum and maximum positions. There are four different set points: one for cooling, one
for ventilation, one for operation during smoke alarm modes, and one for heating. All blower on and off delays still apply.
The minimum/maximum damper positions and static pressure set points are listed as follows (for further details, see Zone
Line Installation instruction 505,090M):
Operation
Cooling
Ventilation
Smoke Alarm Modes
Heating
9.4.1. Bypass Damper Actuator
The M3 Unit Controller is only compatible with bypass damper actuators specified in the Product Specification bulletin and
specified during unit configuration purchase and field­installed. Specified dampers are used to control the supply air volume
for constant air volume with bypass damper zoning applications. The analog control for the actuator is a 2­10VDC with
10VDC being fully closed. This manual uses percent (%) for bypass damper position. For example, 70% bypass damper
position equals 4.4VDC.
Table 39. Bypass Damper Actuator
Bypass Damper Position (% )
0 (closed)
10
20
30
40
50
60
70
80
90
100
Table 37. Variable Frequency Drive Control
Motor Frequency (Hz)
Table 38. Supply CAV with Zone Bypass Damper Control
Minimum Position
Parameter Default
38 20%
38 20%
38 20%
39 20%
Control Voltage (VDC)
18
24
30
36
42
48
54
60
Maximum Position
Parameter Default
40 100%
40 100%
40 100%
40 100%
10
9.2
8.4
7.6
6.8
6
5.2
4.4
3.6
2.8
2
Page 46
Variable Frequency Drive Control Voltage
(VDC)
3
4
5
6
7
8
9
10
Duct Static Pressure
Parameter
37
35
34
36
Default
1.0" in H20.
1.0" in H20.
1.0" in H20.
1.0" in H20.