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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.
Table 37. Variable Frequency Drive Control
Speed % Motor Frequency (Hz)
Variable Frequency Drive Control Voltage
(VDC)
30 18 3
40 24 4
50 30 5
60 36 6
70 42 7
80 48 8
90 54 9
100 60 10
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):
Table 38. Supply CAV with Zone Bypass Damper Control
Operation
Minimum Position Maximum Position Duct Static Pressure
Parameter Default Parameter Default Parameter Default
Cooling 38 20% 40 100% 37 1.0” in H20.
Ventilation 38 20% 40 100% 35 1.0” in H20.
Smoke Alarm Modes 38 20% 40 100% 34 1.0” in H20.
Heating 39 20% 40 100% 36 1.0” in H20.
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 (% ) Control Voltage (VDC)
0 (closed) 10
10 9.2
20 8.4
30 7.6
40 6.8
50 6
60 5.2
70 4.4
80 3.6
90 2.8
100 2