User Manual
Output configu
ration
Load input,
start condition
A B C D
Start condition with switching
command and modulating load
output
Number of
stages or
aggregates
4
1
Start
Run priority
changeover
(Example 2) A x d a No
Description:
- Step-wise control of a modulating aggregate (pump, digital/analog conversion).
- 3 refrigeration machines (1-stage) use a common twin evaporator pump (with integrated variable
speed drive) for changeover operation (2 x 100%) with internal run priority changeover.
- Pump(s) control comprises release and a DC 0…10 V signal for three adjustable steps.
- The function diagram shows one sample setting for the steps.
Plant diagram Function diagram
f
1
f
2
Evp
AI
DI
AO
DO
1
2
3
3123S61
Q
3123D34
20 %
40 %
40 %
1
2 3 4
Start
1
2
3 4
Start
0...10 V
1 2
3
4
Start
2 V
6 V
10 V
Configuration diagram *
CD
C D
X
A
Rotary
step switch 1
*
The start conditions are configured as per the refrigeration machine releases.
Main menu > Commissioning > Extra configuration > Aggregates > Rotary step switch >
Rotary step switch 1…2 >
Configuration
Operating line Setting
Type Flexible
Main menu > Commissioning > Settings > .... or
Main menu > Settings > Aggregates > Rotary step switch > Rotary step switch 1…2 >
Operating line Setting
[Switching value 1] load 20 %
[Switching value 2] load 40 %
[Switching value 3] load 40 %
Min output A 0.0
Output A 1.0
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Siemens Switching and monitoring device RMS705B CE1P3124en
Building Technologies Aggregates 01.04.2010