Program Stop Function; Forced Intermittent Operation (<24 Hours); Low-Fire Shutdown - Siemens LMV37.4 Series Basic Documentation

Building Technologies
7.5.4.7.

Program stop function

To simplify the burner settings in connection with commissioning and service work, the
program sequence of the LMV37.4 can be stopped at the following positions:
1) Air damper in prepurge position
2) Ignition position
3) Interval 1
4) Interval 2
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
Program stop
0 = deactivated
1 = prepurge position (phase 24)
208
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 LMV37.4 halts
at one of the program stops, a message appears on the display of the AZL2.
P
V h min s
Figure 36: Message in the case of program stop
Example: c:204 alternating with d:24 corresponds to a program stop in the prepurge
position.
7.5.4.8. Forced intermittent operation (<24 hours)
When forced intermittent operation is activated, the unit shuts down for a moment
after 23 hours and 45 min of uninterrupted operation, followed by an automatic restart.
Forced intermittent operation is a standard feature.
No. Parameter
Gas. Forced intermittent operation
239 0 = deactivated
1 = activated
Oil: Forced intermittent operation
279 0 = deactivated
1 = activated
7.5.4.9.

Low-fire shutdown

To prevent the boiler from being shut down under full or nearly full load conditions,
electronic fuel-air 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).
Basic documentation LMV37.4...
7 Basic unit LMV37.4
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17.12.2018