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Output configuration
Load input,
start condition
A
B
C
D
Modulating load input with
switching command outputs and
modulating load outputs
Number of
stages or
aggregates
4
1
Start
Run priority
changeover
(Example 4)
A+B+C
a
d a d a d a
Yes
Description:
- 3 refrigeration machines with internal, modulating, inlet temperature-dependent output control.
- RMS705B controls to a constant temperature difference at a pressureless header to ensure the
direction of flow from cold to hot.
-As a result, the main temperature flow is the same as the refrigeration machines' outlet temperature.
- The water volume is controlled via 3-port valves via evaporators in sequence.
- If more water is demanded, the pump switches on, the refrigeration machine is released, and finally,
the 3-port valve opens.
- To balance out the number of operating hours, the run priority of the refrigeration machines follows
the first-in, first-out principle.
- The next refrigeration machine is switched on in the event of a fault (fault changeover).
Plant diagram
Function diagram
3
3
AI
DI
AO
DO
T
T
1
2
31
2
3
S
53
1
1
2
2
3
3
X
P
0 %
0 %
Q
X
P
100 %
B
A
C
100 %
Q
31
23
D
30
B
C
C
B
A
A
Configuration diagram
C D
C
D
X
C
A
B
C
Rotary
step switch 1
Modul. output
Modul. output
Modul. output
Main menu > Commissioning > Extra configuration > Aggregates > Rotary step switch >
Rotary step switch 1…2 >
Configuration
Operating line
Setting
Type Linear
85 / 216
Siemens
Switching and monitoring device RMS705B
CE1P3124en
Building Technologies
Aggregates
01.04.2010