27 33-00462—05
Selecting Return Air Temperature
Sensor Mounting Location
NOTE: When the return sensor is used with T10+ & EIM, If
there's a communication loss with the thermostat, the
backup algorithm will turn on heating stages if the
return air temperature is < 56.0°F and run until the
return air temperature reaches 58°F.
The backup algorithm will turn on cooling stages if
the return air temperature is > 88.0°F and run until
the return air temperature reaches 86°.
Install the Return Air Temperature Sensor on the return duct in
a location where the air is mixed well. Mount the Return Air
Temperature Sensor downstream of a Bypass Humidifier,
Dehumidifier or Ventilator. See Fig. –66.
Selecting Discharge Air Temperature
Sensor Mounting Location
1. Mount the Discharge Air Temperature Sensor on the
supply duct in a location where the air is mixed well.
Mount the Discharge Air Temperature Sensor out of
sight of the A-Coil/Heat Exchanger when possible. See
Fig. .
2. When possible, mount the Discharge Air Temperature
Sensor upstream of a Steam Humidifier, a Fan Powered
Humidifier or a Dehumidifier that is ducted to the supply.
See Fig. 63–64.
3. Resideo does not recommend wiring a discharge
sensor to the EIM in a zoned system. A discharge air
sensor can wire to a Resideo TrueZONE panel and the
panel will do the high/low limit protection for the system.
4. If space does not allow a Discharge Air Temperature
Sensor upstream of a Steam Humidifier or Fan Powered
Humidifier, mount the Discharge Air Temperature
Sensor downstream of the Humidifier.
Fig. 62.
Fig. 63.
Fig. 64.
MOUNT DISCHARGE
SENSOR HERE
M33074
HEAT
EXCHANGER
BLOWER
VENTILATOR
OR
DEHUMIDIFIER
MOUNT RETURN
SENSOR HERE
DOWNSTREAM OF
VENTILATOR OR
DEHUMIDIFIER
A-COIL
MOUNT RETURN
SENSOR HERE
MOUNT DOWNSTREAM
OF BYPASS HUMIDIFIER,
DEHUMIDIFIER OR
VENTILATOR
HEAT
EXCHANGER
BLOWER
VENTILATOR
OR
DEHUMIDIFIER
MOUNT
DISCHARGE
SENSOR HERE
BYPASS
HUMIDIFIER
M33079A
M39061
HEAT
EXCHANGER
BLOWER
STEAM OR
FAN
POWERED
HUMIDIFIER
ALTERNATE MOUNTING LOCATION
FOR DISCHARGE SENSOR
MOUNT RETURN
SENSOR HERE
DOWNSTREAM OF
VENTILATOR OR
DEHUMIDIFIER
MOUNT
DISCHARGE
SENSOR HERE
ABOVE CENTER
OF A-COIL
UPSTREAM OF
STEAM OR FAN
POWERED
HUMIDIFIER
VENTILATOR
OR
DEHUMIDIFIER