Functions - Basic Documentation - RDF302 - RDF302.B - RDF302/VB

Semi-flush mount room thermostats with RS485 Modbus communications RDF302, RDF302.B, RDF302/VB

Product Family
Product Group
Thermostats (temperature controller with sensor)
Content Language
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Technical Documentation > Basic Documentation
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Fan coil units via ON/OFF outputs:

  • 2-pipe system *

  • 2-pipe system with electric heater

  • 4-pipe system

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

  • Chilled / heated ceiling *

  • Chilled / heated ceiling with electric heater

  • Chilled / heated ceiling and radiator / floor heating

Compressors: via ON/OFF control

  • 1-stage compressors in DX type equipment

  • 1-stage compressors in DX type equipment with electric heater

* with both ON/OFF or modulating control output

The room thermostats are delivered with a fixed set of applications.

The relevant application is selected and activated during commissioning using one of the following tools:

  • Local DIP switch and HMI

  • Modbus commissioning tools


  • Operating modes: Comfort, Economy and Protection

  • ON/OFF or 3-position control outputs (relay)

  • Output for 3-speed or 1-speed fan

  • Automatic or manual heating / cooling changeover

  • Backlit display

  • AC 230 V operating voltage


  • Room temperature control via built-in temperature sensor or external room temperature / return air temperature sensor

  • Changeover between heating and cooling mode (automatic via local sensor or Modbus, or manually)

  • Selection of applications via DIP switches or commissioning tool.

  • Select operating mode via operating mode button on the thermostat

  • 1- or 3-speed fan control (automatically or manually)

  • Display of current room temperature or setpoint in °C and/or °F

  • Display of outdoor temperature or time of day via Modbus

  • Minimum and maximum limitation of room temperature setpoint

  • Key lock (automatically, manually or via Modbus)

  • 2 multifunctional inputs, freely selectable for:

    - Operating mode switchover contact (keycard, window contact, etc.)

    - Sensor for automatic heating / cooling changeover

    - External room temperature or return air temperature sensor

    - Dew point sensor

    - Electric heater enable

    - Fault input

    - Monitor input for temperature sensor or switch state

  • Advanced fan control function, e.g. fan kick, fan start, selectable fan operation (enable, disable or depending on heating or cooling mode)

  • “Purge” function together with 2-port valve in a 2-pipe changeover system

  • Reminder to clean fan filters

  • Floor heating temperature limitation

  • Reload factory settings for commissioning and control parameters

  • RS 485 Modbus (terminals +, - and REF) for communication with Modbus compatible devices