Siemens RDG100 Documentation page 17

Purge function
Caution
Avoid damage from
moisture
Minimum output
on-time / off-time
Floor heating /
Floor cooling
Floor heating
limitation function
Recommended values
for P51:
Siemens
Building Technologies
Tel: 01823 665660
Heronhill - for all your Siemens requirements
The changeover sensor ensures changeover from heating to cooling mode based
on the acquired water temperature. We recommend activating the purge function
(parameter P50) with 2-port valves. This function ensures correct acquisition of the
medium temperature even if the 2-port valve is closed for an extended period of
time. The valve is then opened for 1 to 5 minutes (adjustable) at 2-hour intervals
during off hours.
The purge function (parameter P50) must be disabled if the thermostat is used in
compressor-based applications.
In very warm and humid climates, the fan can be run periodically or continuously at
a low fan speed (e.g. in empty apartments or shops) in Energy Saving mode by
setting parameter P61, in order to avoid damage from moisture due to lack of air
circulation. See also section 4.9 "Fan control", under "Fan kick function".
Limit the on/off switching cycle to protect the compressor and reduce wear and
tear. The minimum output on-time and off-time for 2-position control output can be
adjusted from 1 to 20 minutes via parameters P48 and P49.
The factory setting is 1 minute.
Readjusting the setpoint or heating / cooling mode changeover immediately results
in calculation of the output status; output Y11/Y21 may not hold the minimum 1-
minute on/off time.
If parameter P48 or P49 is set to above 1 minute, the minimum on/off time for the
control output is maintained as set, even if the setpoint or changeover mode is
readjusted.
This function is only available for on/off control with RDG100, RDG100T and
RDG110.
All heating sequences can also be used for floor heating.
You can use fan coil heating / cooling sequences for floor heating or cooling by
disabling the fan via parameter P52.
The temperature should be limited for 2 reasons: comfort and protection of the
floor.
The floor temperature sensor, connected to multifunctional input X1 or X2, acquires
the floor temperature. If the temperature exceeds the parameterized limit
(parameter P51), the heating valve is fully closed until the floor temperature drops
to a level 2 K below the parameterized limit.
This function is factory-set to OFF (disabled).
Input X1 or X2 must be commissioned accordingly (P38 or P40 = 1).
See section 4.10 "Multifunctional input".
Living rooms:
Up to 26 °C for long-term presence, up to 28 °C for short-time presence.
Bath rooms:
Up to 28 °C for long-term presence, up to 30 °C for short-time presence.
RDG100, RDG100T, RDG110, RDG140, RDG160 Basic Documentation
Functions
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28 May 2009
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