Siemens LMV50 Series Manual page 116

Function diagrams
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Building Technologies
Example 1: Reaction thresholds Q2 and Q3 for switching stages 2 and 3 on are not
reached. In this case, stage 1 is already switched off when threshold
W+SD_Stage3Off is reached (low-fire operation).
SD_Stage1Off
SD_Stage2Off
SD_Stage3Off
W
SD_Stage1On
R=ON
Stage1
Stage 2
Stage 3
Figure 57: Multistage control – function diagram 1
Example 2: Reaction thresholds Q2 and Q3 for switching on stages 2 and 3 are
exceeded and the stages are switched on.
In this case, stage 1 is switched off when threshold W+ SD_Stage1Off is
reached.
SD_Stage1Off
SD_Stage2Off
SD_Stage3Off
W
SD_Stage1On
R=ON
Stage 1
Stage 2
Stage 3
Figure 58: Multistage control – function diagram 2
Basic Documentation LMV5...
7 Boiler controller / load controller
Setpoint
Setpoint
Q2
Q3
Actual value
Actual value
7550f10E/0502
7550f09E/0502
Q2
Q3
CC1P7550en
22.05.2018