Monitoring The Positions - Siemens LMV37.4 Series Basic Documentation

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10.5 Monitoring the positions

To monitor the actuator's actual positions, an optical incremental transducer with a reso-
lution of 0.7° is used. The correct position of the drive shaft is ensured by comparing the
motor steps made with the position obtained from the incremental transducer. Due to
the different resolutions of motor steps and incremental transducer plus the selected tol-
erance band, the following error identification band is obtained. The decision where, in
the error identification band, shutdown takes place depends on the currently required
position.
For the default setting made in the factory, the error detection band is as follows:
Smallest position error where an error can be detected
Greatest position error where an error is securely detected (default setting
parameter 606)
The presetting of 1.7° (default setting, parameter 606) is suited for use with actuators
type SQN1... and SQM3...
Note
When using SQN1... actuators equipped with plastic gear trains, we recommend to
change the preset values as follows:
Type Value
SQN13.14... 1,7°
SQN14.14... 1,7°
SQN13.17... 2,2°
SQN14.17... 2,2°
When referencing under output conditions, the resilience of the actuator's gear train
must also be taken into consideration:
Type Resilience at max.
reference rated driving
torque
SQM33.41...
SQM33.51...
SQN13.14...
SQN13.17...
SQN14.14...
SQN14.17...
The error detection time is <1 second.
Caution!
This means that – for the design and setting of the burner – a position error re-
sulting from the sum of
greatest position error from which an error is detected in all positions
-
resilience at the max. rated torque
-
mechanical influence from the link between actuator and regulating unit
-
(e.g. coupling)
must not lead to a critical state in terms of safety.
No. Parameter
Tolerance limit of position monitoring (0.1°)
Index 0 = fuel
606 Index 1 = air
Greatest position error where an error is securely detected
→ Error detection band: (P606 -0.6°) up to P606
Error Diagnostic
code code
86 0
87 0
Basic documentation LMV37.4...
10 Actuators X53 / X54
0.2°
0.2°
0.3°
0.8°
0.3°
0.8°
Meaning for the LMV37.4... system
Position error fuel actuator
Position error air actuator
1.1°
1.7°
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CC1P7546en
01.12.2009