Siemens RDG20 KN Series - Sensors and Changeover Functions

Functions
Additional functions
4
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Functions (parameters)
Description
Standalone
RDG
KNX
Humidity (RDG2..KN) [➙ 60]
● Humidity control (P007, P450)
Limit min. and max. humidity in the room
✓
2..KN
Scheduler [➙ 64]
● Scheduler (P005)
To set time schedule
✓
✓
2..
M/S, manager/subordinate (RDG2..KN)
[➙ 65]
To save energy in open spaces
✓
2..KN
Preventive operation [➙ 69]
● Avoid cold air in heating mode (P365)
To make sure reaching setpoint temperature
during heating mode
✓
✓
2..
● Avoid damage from moisture (P363,
P364)
To prevent from damage of moisture
✓
✓
2..
NFC communication [➙ 69]
● NFC (P500)
NFC communication via Siemens smartphone
application
✓
✓
2..
IAQ - CO2 monitoring and control (RDG2..KN) [➙ 69] (RDG204KN, RDG264KN)
● IAQ monitoring (P450)
● CO
2
indication (P009)
● IAQ control (P023, P450, P453, P454,
P455, P456)
● Forced ventilation (P003)
● Frost protection (P109)
To monitoring and controlling indoor air quality
✓
2..4KN
Power reserve clock (RDG2..T) [➙ 76]
Power reserve clock for 20 h during power
failure
✓
2..T
Read live data via PCT Go [➙ 160]
Service function for installers to check the cor-
rect installation, commissioning, and working
conditions of the thermostats
✓
✓
2..
4.6.1 Sensors and changeover functions
The heating/cooling changeover information is received via bus. This is only
possible if the control sequence is set to automatic heating/cooling changeover
(P001 = 2) and no local input (X1, X2, U1) is assigned to this function.
If required information is unavailable (e.g., due to data communication issues,
power failure, etc.), the thermostat operates in the last valid room operating mode
(heating or cooling).
If a cable temperature sensor (LG-Ni1000 or NTC 3k) is connected to X1/X2/U1
(RDG2..KN)/X3 (RDG2..T), and P150/P153/P155 is set to 2, the water temperature
acquired by the changeover sensor is used to change over from heating to cooling
mode, or vice versa.
● When the water temperature is above 28 °C (adjustable via P060), the
thermostat changes over to heating mode and remains in heating mode until
the temperature drops below 16 °C (adjustable via P059).
● When the water temperature is below 16 °C (P059), the thermostat changes
over to cooling mode and remains in cooling mode until the temperature
exceeds 28 °C (P060).
● If the water temperature is between the 2 changeover points immediately after
power-up (within hysteresis), the thermostat starts in the previous mode.
Heating/cooling
changeover via bus
(KNX) (RDG2..KN)
Heating/cooling
changeover
Automatic
heating/cooling
changeover via
changeover sensor