Siemens RDF302/VB User Manual

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Siemens RDF302 Basic documentation CE1P3079en
Smart Infrastructure 2022-06-17
3. Functions
3.1 Temperature control
Setting of the control parameters (P01, etc., mentioned throughout the document)
is described in section 3.13.
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:
• ON/OFF control (2-position)
• Modulating PI/P control with 3-position control output (only for 2-pipe
applications)
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.
The acquired room temperature (internal or external sensor) is also available as
information on the Modbus.
• With automatic changeover or continuous heating / cooling, symbols /
indicate that the system currently heats or cools (heating or cooling output is
activated).
• With manual changeover (P01 = 2), symbols / indicate that the system
currently operates in heating or cooling mode. Thus, the symbols are displayed
even when the thermostat operates in the neutral zone.
Concurrent display of the current temperature or setpoint in °C and °F (parameter
P07 = 1) is possible on the thermostats.
The outside temperature can be displayed on the room thermostat by setting
parameter P07 = 2. This temperature value has only information character which
comes from the master device in the Modbus network.
Time of day via Modbus can be displayed on the room thermostat by setting
parameter P07 = 3 or 4. The display format is either in 12- or in 24-hour format.
The information can be received from a master device in the Modbus network.
General note:
Parameters
Temperature control
Display
Room temperature
/
Concurrent display of
°C and °F
Outside temperature
Time of day

Siemens RDF302/VB Specifications

General

Brand	Siemens
Model	RDF302/VB
Category	Thermostat
Language	English