Use 

Fan coil units via ON/OFF or modulating control outputs:

•  2-pipe system
•  2-pipe system with electrical heater
•  2-pipe system and radiator / floor heating
•  4-pipe system
•  4-pipe system with electrical heater
•  2-stage heating or cooling system

Chilled / heated ceilings (or radiators) via ON/OFF or modulating control outputs:

• Chilled / heated ceiling
• Chilled / heated ceiling with electrical heater
• Chilled / heated ceiling and radiator / floor heating
• Chilled / heated ceiling, 2-stage cooling or heating

Heat pumps with dx type equipment:

• 1-stage compressor for heating or cooling
• 1-stage compressor for heating or cooling with electrical heater
• 1-stage compressor for heating or cooling and radiator / floor heating
• 1-stage compressor for heating and cooling with reversing valve
• 2-stage compressor for heating or cooling 

Functions

Setting of the control parameters (P01, etc., mentioned throughout the document) is described in section 4.15.

The thermostat acquires the room temperature via built-in sensor, external room temperature sensor (QAA32), or external return air temperature sensor (QAH11.1), and maintains the setpoint by delivering actuator control commands to heating and/or cooling equipment. The following control outputs are available depending on the thermostat type:

• 2-position control on RDG100,RDG100T,RDG110
• Modulating PI/P control with 3-position control output on RDG100,RDG100T, 
• Modulating PI/P control with PWM output on RDG100,RDG100T
• Modulating PI/P control with DC0...10V control output onRDG140,RDG160

The switching differential or proportional band is 2 K for heating mode and 1 K for cooling mode (adjustable via parameters P30 and P31).
The integral action time for modulating PI control is 5 minutes (adjustable via parameter P35).

The display shows the acquired room temperature or the Comfort setpoint, selecta- ble via parameter P06. The factory setting displays the current room temperature. Use parameter P04 to display the room temperature or setpoint in °F rather than °C as needed.

If the thermostat is used in a system with manual heating / cooling changeover (P01 = 2), the heating    and cooling symbols on the display show the fan coil or terminal unit's status. Thus, the symbols are displayed even when the thermostat operates in the neutral zone. For all other cases, the heating and cooling symbols are displayed when the heating or cooling output is activated.

Concurrent display of the current temperature or setpoint in °C and °F (parameter P07) is possible on the thermostats without 7-day time program.