66
15.4.1.
Discharge Air Control Heating Outdoor Air Reset
The outside air reset saves energy by gradually decreasing the discharge air set point as the outside air temperature
increases. Refer to section 14.2.1. for further details.
15.4.2.
Discharge Air Control Heating Return Air Reset
The return air reset reduces the possibility of overheating by gradually decreasing the discharge air set point as the return
air temperature increases. Overheating may occur if the zoning system is miss-applied, has an abnormal condition, or
dominant zone. Refer to section 14.2.2. for further details.
15.5. Power Exhaust Operation
The M3 unit controller has power exhaust fan control options that include support for both single‐stage and two‐stage
equipment. The stage control option is triggered based on fresh air damper position. See Power Exhaust Section.
Go to
SETUP / INSTALL and set Configuration ID 1,
position
3
to
(S
=
Single Stage or D
=
Dual Stage).
Go to
SETUP / INSTALL and set Configuration ID 1,
position
4
to
A
=
Damper Position
15.6. Supply Bypass Damper Control
The actuators control the supply air volume for constant air volume units equipped with a bypass damper in zoning
applications. The analog control for the actuator is 2-10VDC. Dampers are closed at 10VDC and fully open at 2VDC. This
manual uses percent (%) to indicate bypass damper position. For example, 70% bypass damper position is equal to
4.4VDC.
Table 40. Supply Bypass Damper Control
Bypass Damper
Position (%)
Control
Voltage (VDC)
Bypass Damper
Position (%)
Control
Voltage (VDC)
Bypass Damper
Position (%)
Control
Voltage (VDC)
Bypass Damper
Position (%)
Control
Voltage (VDC)
0 (closed)
10
30
7.6
60
5.2
90
2.8
10
9.2
40
6.8
70
4.4
100
2
20
8.4
50
6
80
3.6
