12
NOTE
: Select the appropriate menu option to determine the room sensor back-up mode. The back-up mode is used in
the event that the A2 room sensor fails or is disconnected. The following options are available:
NONE
has no back-up mode of control should the A2 room sensor fail.
ROOM SENSOR
option is only available if the control mode is set to NETWORK.
RETURN AIR BACKUP
will default to return air sensor RT16 (should the A2 room sensor fail). The M3 unit controller
will switch over and operate based on the temperature from the return air sensor. RT16 is standard on all units;
therefore M3 unit controller Room Sensor System Mode 3 is the recommended backup mode when units are setup
in the room sensor mode.
THERMOSTAT
will default to a local thermostat if one is installed (should the A2 room sensor fail). The M3 unit
controller will switch over and operate based on the signals from the room thermostat.
NOTE
: The RT16 has a lower resolution than the A2 room sensor and should only be used as back-up.
Figure 3. Backup Mode
2.2.3.
Room Sensor Back-Up Mode Set Points
The following set points are available when primary mode is set to NETWORK THERMOSTAT and the backup sensor
mode is set to either RETURN AIR BACK or ROOM SENSOR. All available set points have a range of 40.0°F to 95.0°F.
The listed values below are defaults.
Occupied Heating set point: 70.0°F
Unoccupied Heating set point: 60.0°F
Occupied Cooling set point: 75.0°F
Unoccupied Cooling set point: 85.0°F
Use parameters 142 and 147 for stage differential and dead-band options to adjust set points in room sensor mode.
