Siemens RDG100KN Basic Documentation page 41

Dehumidification
Note
K N X
R
Dehumidification
Note
Siemens
Building Technologies
When the relative humidity exceeds the maximum setpoint, the thermostat makes
a proportional shift of the temperature setpoint until P76 (max. shift temp setpoint)
is reached. If this control is not enough to reduce the humidity, an external
dehumidifier can be switched on via relay outputs or KNX, when the related relay
function is selected (P72, P73 or P74 is set to7).
The maximum temperature shift setpoint value is reached at setpoint humidity high
(P21) +10%. The contact for the dehumidifier is released at setpoint humidity +
15%.
Applications with a DC fan:
· Enable the function to control the external dehumidifier directly via relay output
by setting P72 (output Q1), P73 (output Q2) or P74 (output Q3) to 7.
When the output is energized, the S-Mode object dehumidification sends the
information "ON" to the bus
· The selected relay output is switched on if relative humidity exceeds the
maximum setpoint +15%
· For applications with On/Off valves on Q1 or Q2 or both, the output Q3 (P74 =
7) is used to control the external dehumidifier
· The relay contact remains closed or open for the minimum On/Off time defined
by P48 or P49
Applications with a 3-speed fan:
· The external dehumidifier is controlled via external DC – On/Off converter
connected to analog output Y50. The output signal is DC 10 V if
dehumidification control is requested
· The output Y50 remains On for a minimum time of 30 seconds (not selectable)
· This function is available without specific settings (P72, P73 and P74 are not
displayed)
The current of the external DC – On/Off converter should not exceed the maximum
output current of the Y50 (max. 5 mA). We recommend using the converter from
Titan (single relay control (IO/1RM) at 3 mA input current).
RDG100KN, RDG160KN, RDG165KN Basic Documentation
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CE1P3191en
2018-07-03