Siemens RDG20 KN Series Basic Documentation page 114

Functions
4
Multifunctional input, digital input
# Input function
11 External temperature
limit
12 Coil flow temperature
13 Hotel presence detector Hotel presence detector input switches the
Hotel
presence
detector
14 Coil return temperature To save energy, the thermostat controls the valve
Note
114 | 180
Description
The sensor is connected to the pipe and
measures the temperature of the floor heating
water. When the value exceeds the selected limit
(P252), heating is stopped. See also Monitoring
and limiting functions [➙ 53]
To avoid cooling flow air in the room, the sensor
measures the coil water temperature and
releases the fan only when the selected minimum
water temperature limit is exceeded (P366). See
also Fan control [➙ 111].
To measure the flow temperature of the return
flow delta temperature control
operating mode to Economy when the room is
unoccupied and symbol
are locked) and returns to previous operating
mode when the room is occupied.
Hotel presence detector is also possible via bus.
In this case, do not assign the function to local
inputs X1, X2 or U1. See also Presence detector
[➙ 49].
to adjust flow speed when ΔT between flow and
return temperature value is less than P061 or
P062. See also Monitoring and limiting functions
[➙ 53].
●
Control action can be changed from normally open (NO) and normally closed
(NC) via P151, P154 or P156.
●
Each input X1, X2 or U1 must be configured with a different function (1...5 &
9...13). Exception: 1, 2 or 3 inputs can be configured as fault (6) or monitor
input (7,8).
●
X1 is factory-set to "External sensor" (1), X2 to "Not used" (0), and U1 to
"Window contact" (3).
For more detailed information, see Application overview [➙ 42].
●
For inputs X1, X2, or U1, one physical switch can be used for up to 20
thermostats (parallel connection).
●
In 4-pipe/2-stage application of RDG26..KN, U1 is fixed as DC output (YC2)
and cannot be set as input.
Caution! Do not mix X1/X2 and U1.
●
For sensors on inputs X1, X2, or U1, the maximum cable length is 80 m.
is displayed (buttons
A6V11545892_en--_c
Type
X1/X2/U1
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