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Building Technologies
Basic Documentation LMV27...
CC1P7541en
9 Connection to load controllers
17.12.2018
9
Connection to load controllers
The LMV27 can be connected to different load controllers. Heat request and the
required burner output are determined in accordance with the priorities of the different
load sources.
9.1 Load controller on contact X5-03, pin 1
This contact is given priority over all load controller sources. A heat request can only be
made when this contact is closed. The contact is safety-related and can also be used in
connection with load controllers featuring an integrated
Temperature limiter
function.
9.2 External load controller via contacts X5-03, pin
2 / pin 3
The heat request is delivered via pin 1. Modulation of burner output is effected via pin 2
and 3. Here, a differentiation is made between modulating and multistage operation
(refer to chapter
Selection of operating mode
).
Modulating operation X5-03 (OPEN pin 3 / CLOSE pin 2)
If input
Open
is active, the burner’s output is increased. If input
Close
is active, the
burner’s output is decreased. If none of the inputs is active, the burner’s output is not
changed.
The rate of integration is 32 seconds for changing the output from low-fire (20%) to high-
fire (100%) or vice versa (parameter 544), that means a burner output from 100% to
20%.
Output integration always takes place in the operating position.
200 ms is the shortest positioning step that is securely detected.
LMV...
Bild 316e/1010
X5
-0
3
Load controller (LR) (ON / OFF)
L
Controller
Controller ON
L
Figure 59: Modulating operation X5-03
No. Parameter
544 Ramp
modulating
Minimum positioning step
To prevent the actuators from making unnecessary position changes when the
preselected target output varies, a minimum positioning step can be set. In that case,
the LMV27 changes the output only when the preselected target output exceeds the
minimum positioning step. This minimum positioning step is only used in modulating
operation.
No. Parameter
123.2 Minimum output positioning step: Output of external load controller contacts