Siemens LMV27.100x2 - Program Stop Function; Forced Intermittent Operation (<24 Hours); Low-Fire Shutdown

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Building Technologies Basic Documentation LMV27... CC1P7541en
7 Basic unit LMV27 17.12.2018
7.5.3.7. Program stop function
To simplify the burner settings in connection with commissioning and service work, the
program sequence of the LMV27 can be stopped at the following positions:
1) Air damper in prepurge position 24
2) Ignition position 36
3) Interval 1 44
4) Interval 2 52
The program stops are integrated in the setting sequence when the plant is
commissioned (refer to chapter Air-fuel ratio curves – settings and commissioning).
After the initial settings, program stops can be activated on the parameter level.
No. Parameter
208
Program stop
0 = deactivated
1 = prepurge position (phase 24)
2 = ignition position (phase 36)
3 = interval 1 (phase 44)
4 = interval 2 (phase 52)
The Program stop function is maintained until manually deactivated. If the LMV27 halts
at one of the program stops, a message appears on the display of the AZL2.
P
Vh
mi n
s%
Bild 160/0807
P
Vh
mi n
s%
Bild 159/0807
Figure 33: Message in the case of program stop
Example: c:204 alternating with d:24 corresponds to a program stop in the prepurge
position.
7.5.3.8. Forced intermittent operation (<24 hours)
When forced intermittent operation is activated, the unit shuts down for a moment
after 23 hours and 45 minutes of uninterrupted operation shutdown and followed by an
automatic restart.
With the LMV27, forced intermittent operation cannot be deactivated.
7.5.3.9. Low-fire shutdown
To prevent the boiler from being shut down under full or nearly full load conditions,
electronic air-fuel ratio control can run the burner to the low-fire position first when there
is no more request for heat (refer to chapter End of operating position).