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Siemens
User Manual
CE1U2353en
Building Technologies
Cooling circuit
2014-07-30
The function is deactivated in the following circumstances:
·
No room temperature sensor
·
"Room temp limitation" = ---
·
"Room influence“ (928) = --- (weather compensation only)
ON
TRKw-SDR
2
3
5
5
Z
1
0
TRKw
TRx
P
OFF
°C
TRx
Actual value of room temperature
TRKw Room temp. setpoint cooling
(with summer compensation)
SDR
Room switching differential
B
Pump
t
Time
Mixing valve control
Line no.
Operating line
938
Mixing valve cooling offset
939
Actuator type
2-position ¦ 3-position
940
Switching differential 2-pos
941
Actuator running time
945
Mixing valve in heating mode
Control ¦ Open
The refrigeration demand from the mixing valve circuit to the heat source is reduced by
the programmed value. The purpose of this reduction is to enable the mixing valve
controller to compensate for the fluctuation in temperature caused by the heat source
(2-point control action).
2-position
The controller drives the actuator with only 1 relay output. When the output delivers a
signal, the valve opens. When there is no signal, the valve will close automatically.
3-position
The controller drives the actuator with 2 relay outputs. 1 of the outputs is used for
opening the valve and 1 for closing the valve.
For the 2-position actuator, the "2-position switching differential" must also be adapted.
Three-position actuators are not affected by the switching differential.
For the 3-position actuator, the running time of the mixing valve actuator can be
adjusted. The actuator running time has no effect on two-position actuators.
Defines the position of the mixing valve (Y1/Y2) when heating mode is active.
This parameter has no effect in systems with hydraulically separate heating and cooling
circuits.
Controls
The valve is used for control in heating and cooling mode.
Open
The valve is used for control in cooling mode and is open in heating
mode.
Dewpoint monitoring
Line no.
Operating line
946
Dewpt monitor locking time
Mixing valve cooling offset
Actuator type
Switching differential 2-
pos
Actuator running time
Mixing valve in heating
mode