User Manual

Main menu > Commissioning > Communication > Distribution zones >
Setting values
Operating line Range Factory setting
Refrigeration distribution zone 1…31 1
Main menu > Commissioning > Settings > .... or
Main menu > Settings > Aggregates > Refrigeration demand >
Operating line Range Factory setting
Limit value request on 0...100 % 10 %
Limit value request off 0...100 % 5 %
Chilled water flow setpoint 0...140 °C 6 °C
Flow temperature increase max 0…100 K 0 K
Control action Slow, Medium, Fast Medium
Request evaluation Average, Maximum Maximum
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.
Limit value re
quest on
[%]
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.
Chilled wate
r flow
setpoint, Flow
temperature increase
max
In this ca
se, 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%:
Max. flow temperature = "Chilled water flow setpoint" + "Flow temperature increase max"
This optimization function is enabled only if value "Flow temperature increase
max" > 0 (factory setting: 0 = disabled).
Note
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.
Control action
145 / 216
Siemens Switching and monitoring device RMS705B CE1P3124en
Building Technologies H/C demand, H/C changeover 01.04.2010