Siemens LMV50 Series Manual page 121

External predefined
setpoint
External predefined load
External predefined
load, modulating
Building Technologies
If parameterized for Int LC X62, the input signal is converted to pressure or temperature
according to the parameterization of the measuring range and interpreted as the boiler's
setpoint. The setting range automatically corresponds to the parameterized measuring
range of the actual value and can also be limited.
Setpoint
min. measuring range
I (mA) 0 / 4
U (V) 0 / 2
The detection of short-circuits and line interruptions is ensured – similar to the sensor
inputs (but not when configured for DC 0...10 V / 0...20 mA). The request for heat
results from the difference of actual value and setpoint.
Parameter Ext MinSetpoint
Ext MaxSetpoint
Example: DC 0...10 V or 4...20 mA with MRange TempSens = 150 °C
Setting parameter Ext MinSetpoint = 33%
Setting parameter Ext MaxSetpoint = 80%
External
setpoint-min
0 °C
Figure 59: Setpoints
If parameterized for Ext LC X62, the input signal is interpreted as the predefined load.
This is internally transmitted to the fuel-air ratio control system where it is translated
into the respective actuator driving signals. Since the internal controller is inactive in
this operating mode, control must be performed externally. If, in addition, a temperature
sensor Pt100 (and/or Pt1000, LG-Ni1000 sensor) is connected, it is also possible to
use the internal temperature limiter function with the external predefined load.
Low-fire
I (mA) 0 / 4
U (V) 0 / 2
Basic Documentation LMV5...
7 Boiler controller / load controller
Setpoint
max. measuring range
20
10
External
setpoint-max
Example
Nominal load
20
10
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CC1P7550en
22.05.2018