4. Use the up and down arrows to navigate to Equipment Size.
5. Press Equipment Setup and select Oversized.
6. Press Save and the back arrow to return to the previous screen.
Changeover
About this task:
Pressure-Dependent VAV systems and two-pipe fan coils require changeover detection in order to
switch seasonal operation between heating and cooling modes. The TEC supports the following
methods for changeover: automatic changeover using an analog sensor (thermistor), automatic
changeover using a binary switch, or remote changeover from a BAS and manual changeover.
For automatic changeover, a supply temperature sensor or switch must be connected to the
Changeover Sensor (COS) input of the TEC. Changeover Mode must be set to Auto, and Supply
Temp Type must be set for Analog Sensor, Cooling N.C. (cooling when switch is closed), or Heat-
ing N.C. (heating when switch is closed). When an analog sensor is used, the changeover setpoint
can be adjusted. The changeover logic applies a 10-degree Fahrenheit differential to the setpoint.
The system switches to cooling mode when the temperature drops below the changeover set-
point and remains in cooling mode until the measured temperature has risen 10 degrees above the
changeover setpoint.
To configure automatic changeover:
1. Press the Menu icon.
2. Press Setup.
3. Press Equipment Setup.
4. Press Changeover.
5. Press Changeover Mode and select Auto.
6. Press Supply Temp Type and select Analog Sensor, Cooling N.C., or Heating N.C.
7. If using an Analog Supply Temp Sensor, press Supply Temp Type and adjust accordingly.
8. Press Save and the back arrow to return to the previous screen.
Additionally, the thermostat controller supports manual changeover. To configure manual
changeover:
1. Press the Menu icon.
2. Press Setup.
3. Press Equipment Setup.
4. Press Changeover.
5. Press Changeover Mode and select Heating or Cooling.
6. Press Save and the back arrow to return to the previous screen.
You need to ensure that the Supply Temp type is set to Analog Sensor. The Changeover Mode is
also exposed to the BAS through the CGOVR-MODE and can be commanded from the BAS.
On two-pipe or VAV systems without an automatic changeover, or on four-pipe systems, you can
use RSEN or COS as a monitor-only point for reading an analog sensor. By setting the controller
in four-pipe mode, or selecting Heating or Cooling for Changeover Mode, the controller defaults
to monitor-only mode for RSEN or COS and exposes the value to the network as the supply
temperature.
31TEC3000 Series On/Off or Floating Fan Coil Thermostats Installation Guide
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