Connection To Load Controllers; Controller On Contact X5-03 Pin 1; External Load Controller Via Contacts X5-03, Pin 2 / Pin 3 - Siemens LMV37.4 Series Basic Documentation

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9

Connection to load controllers

The LMV37.4... system 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 Controller on contact X5-03 pin 1

This contact is given priority over all load 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 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 to high-fire
(parameter 544), that is from 20 % to 100 %, or vice versa.
Output integration always takes place in the operating position.
200 ms is the shortest positioning step that is securely detected.
Load controller (LR) (ON / OFF)
Figure 60: Modulating operation X5-03
Note!
When the Switching back to pilot function is used, the load controller inputs OPEN
CLOSE (X5-03 pin 2 and 3) are not available (refer to chapter Switching back to pilot).
Analog input X64 is used as the power source in this case.
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 basic unit 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
Basic documentation LMV37.4...
9 Connection to load controllers
LMV...
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Bild 316e/1010
Controller
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Controller ON
CC1P7546en
20.09.2013