Siemens Synco 700 RMZ785 Basic Documentation page 144

Setting values
Limit value request on
Chilled water flow
setpoint, Flow
temperature increase
max
Max. flow temperature = "Chilled water flow setpoint" + "Flow temperature increase max"
Note
Control action
Siemens
Building Technologies
Main menu > Commissioning > Communication > Distribution zones >
Operating line
Refrigeration distribution zone
Main menu > Commissioning > Settings > .... or
Main menu > Settings > Aggregates > Refrigeration demand >
Operating line
Limit value request on
Limit value request off
Chilled water flow setpoint
Flow temperature increase max
Control action
Request evaluation
This settable value prevents entire plants from being switched on (e.g. refrigeration
plants) in the case of extremely low refrigeration requests. Switching on (i.e. routing
as a bus signal or to outputs Q, d, Y, a) takes place only when the set value "Limit
value request on" is exceeded.
On
Use setting value "Flow temperature increase max" to enable optimization, which
determines the current optimum flow temperature for control from the received
request signals.
In this case, value "Flow temperature increase max" can be floating, i.e. deviate
from the set value for "Chilled water flow setpoint".
This current flow temperature is controlled to a 90% valve position of the
refrigeration consumer with the greatest demand (evaluation of request in setting
"Maximum") so that:
 Valve position < 90 %: The flow temperature is increased continuously until
value "Chilled water flow setpoint" plus "Flow temperature increase max" is
reached.
 Valve position > 90 %: The flow temperature is decreased continuously until
value "Chilled water flow setpoint" is reached.
As a result, the following max. flow temperature setpoint can be set at valve
positions ≤ 90%:
This optimization function is enabled only if value "Flow temperature increase
max" > 0 (factory setting: 0 = disabled).
The "Control action" of the flow temperature on the setpoint shifts can be set in
three steps ("Fast", "Medium", "Slow") to adapt to the plant.
Switching and monitoring device RMS705B
H/C demand, H/C changeover
Range
1...31
Range
0...100 %
0...100 %
0...140 °C
0...100 K
Slow, Medium, Fast
Average, Maximum
[%]
Factory setting
1
Factory setting
10 %
5 %
6 °C
0 K
Medium
Maximum
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CE1P3124en
01.04.2010