Siemens RDG20 KN Series Basic Documentation page 61

Note
P461 < 0 K
Note
P461 = 0 K
Calibration humidity
(P007)
A6V11545892_en--_c
For heating and cooling applications, the value of the dead zone (P055) must be
bigger than the maximum shifting temperature setpoint (P461), to avoid
changeover between heating and cooling sequences in the event of fast humidity
changes in the room.
For applications with powerful cooling water systems (temperature of cold surfaces
is lower than the dewpoint temperature of the humid air), dehumidification can be
reached by reducing the room temperature, as the vapor in the air condensates on
the surface of the cooling equipment. In this case, set P461 to a negative value (-
0.5...-3.0 K).
This setting is typically used for cooling applications with fan coil units or split units.
When the thermostat is in cooling mode or in the dead zone, the temperature
setpoint cooling is shifted only when P461 is less than 0 K. The temperature
setpoint heating, if available, remains unchanged. The thermostat guarantees a
minimum dead zone between both setpoints.
When P461 is set to 0 K, the temperature setpoints for heating, cooling or both are
not shifted. Dehumidification can be achieved by releasing the relay contact for the
dehumidifier. The release contact is switched on at 5% above the high humidity
setpoint and off at 5% below.
Relative humidity measured by the built-in sensor is also displayed if P009 is set to
5. The sensor can be calibrated (+/-10%) via P007.
When P009 = 5, thermostat can monitor relative humidity via HMI or bus.
For application examples with humidity control, see Humidity control [➙ 160].
Functions
4
Additional functions
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