User Manual
Main menu > Settings > Aggregates > Refrigeration demand >
Setting values
Operating line Range Factory setting
Setpoint at 0 Volt –50…+50 °C 12 °C
Setpoint at 10 Volt 50…500 °C 6 °C
Limit value –50…+250 °C 12 °C
Note
s
"Setpoint at 0 Volt" determines the flow temperature setpoint at DC 0 V.
"Setpoint at 10 Volt" determines the flow temperature setpoint at DC 10 V.
"Limit value" means limit value for refrigeration demand: Temperatures below
this level are interpreted as "no refrigeration demand".
As long as the flow temperature setpoint does not exceed the set limit value,
DC 0 V output signal is issued. If the temperature drops below the limit value, the
corresponding output signal is issued until the setpoint again exceeds the limit
value plus hysteresis of 0.5 K.
– Output signal Y (DC 0…10 V) for refrigeration demand must correspond to a
flow temperature setpoint range of 6…13 °C. This limit value should be at 12 °C.
Applicatio
n example
– The chilled water flow setpoint may float between 6…9 °C depending on
demand.
– An output signal corresponding to the set characteristic is to be issued at output
Y.
DC 0..10 V output is only a continuous signal if "Flow temperature increase max" >
0 is set.
Note:
The diagram shows the values of the parameters to be set and the resulting
progression of the refrigeration demand signal:
11
0
10
Y
[ V ]
[°C]
3123D12
78 910 126
2
1
3
13 14
w
TV
4
5
6
Setpoint in °C at DC 0 V
Setpoint in °C at DC 10 V
Limit value
Chilled water flow setpoint = 6 °C
Flow temperature increase max,
here 3 K
Shifting range for output signal
w
TV
: Current flow temperature setpoint
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Siemens Switching and monitoring device RMS705B CE1P3124en
Building Technologies H/C demand, H/C changeover 01.04.2010