Siemens LMV27.100x2 Basic Documentation page 84

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Building Technologies
Shifting multistage operation (OPEN pin 3 / CLOSE pin 2)
Using a simple thermostat, a modulating burner can be operated in shifting 2-stage
mode. In that case, there must be a firm connection between terminal CLOSE and the
live conductor (L), and terminal OPEN must be connected to the thermostat or the load
controller.
If OPEN is inactive, the active CLOSE terminal drives the burner to low-fire.
If OPEN becomes active, priority is given over terminal CLOSE so that the output is
increased by driving the burner to high-fire.
Load controller (LR) (OPEN)
Load controller (LR) (CLOSED)
Load controller (LR) (ON/OFF)
Figure 62: Shifting multistage operation (OPEN pin 3 / CLOSE pin 2)
Parameter 205 is needed to interchange usage of the load controller contacts for
multistage operation. In that case, the burner switches to the third stage when input
Stage 2 is active (load controller OPEN). This has no impact on modulating operation.
No. Parameter
Function Load controller contacts multistage
205 0 = standard
1 = stages interchanged
Modulating
X5-03 pin 1
X5-03 pin 2
X5-03 pin 3
2-stage
X5-03 pin 1
X5-03 pin 2
X5-03 pin 3
3-stage
X5-03 pin 1
X5-03 pin 2
X5-03 pin 3
Basic Documentation LMV27...
9 Connection to load controllers
LMV...
L
Standard
ON / OFF Low-fire
Close Signal Close
Open Signal Open
Standard
ON / OFF Stage 1
Close Stage 2
Open Stage 2
Standard
ON / OFF Stage 1
Close Stage 3
Open Stage 2
7546z203e/0913
Stages interchanged
Low-fire
Signal Close
Signal Open
Stages interchanged
Stage 1
Stage 1
Stage 2
Stages interchanged
Stage 1
Stage 2
Stage 3
CC1P7541en
ON/OFF
17.12.2018