Basic Documentation

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Siemens Universal controllers RMU710B, RMU720B, RMU730B CE1P3150en
Building Technologies Refrigeration demand 03.10.2011
26.4.1 Internal refrigeration demand
The calculated request signal is available as internal signal. To this end, function
block "Refrigeration demand" offers output (
d).
The demand as a digital value can be further handled e.g. via a logic block, etc., to
e.g. switch on a pump when a refrigeration request is sent.
26.5 Refrigeration demand modulating ( )
In addition to the refrigeration demand relay, the refrigeration demand can be
provided at a modulating output for other devices.
Main menu > Commissioning > Extra configuration > Aggregates > Refrigeration demand>
Operating line Adjustable values / remarks
Refrig demand
modulating
---, N.Y1, N.Y2 / activate output
Main menu > Commissioning > Settings > .... or
Main menu > Settings > Aggregates > Refrigeration demand >
Operating line Range Factory setting
Setpoint at 0 Volt
Setpoint at 10 V…250 °C
12 °C
Setpoint at 10 Volt
–50 °C…setpoint at 0 V
6 °C
Limit value
Setpoint at 10 V…setpoint at 0 V
12 °C
"Setpoint at 0 V" determines the flow temperature setpoint at DC 0 V.
"Setpoint at 10 V" determines the flow temperature setpoint at DC 10 V.
Limit value means limit value for refrigeration demand: Temperatures above 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.
11
0
10
Y
[ V ]
[°C]
78 910 126
2
1
3
13 14
w
TV
Key:
1. Setpoint in °C at DC 0 V
2. Setpoint in °C at DC 10 V
3. Limit value
W
TV
: Current flow temperature setpoint
Purpose and function
Purpose
Configuration
Setting values
Explanations relating to
the setting values
Diagram relating to the
setting values
(application example)