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Building Technologies
Basic Documentation LMO39…
CC1P7154en
7 Functions
15.03.2018
7.6 Control sequence in the event of fault
If a non-alterable lockout occurs, the outputs for the fuel valves, the burner motor and the
ignition equipment are always immediately deactivated (<1 second).
Cause
Response
Mains failure
Safety shutdown, followed by restart on restoration of mains
voltage
Voltage below undervoltage threshold
Safety shutdown, followed by restart when undervoltage
threshold is exceeded
Extraneous light during prepurge time, 5 seconds
before fuel valve 1 release
Non-alterable lockout, blink code 4
Extraneous light during waiting time
Prevention of startup, a non-alterable lockout occurs after
approx. 30 seconds at the latest, blink code 4
No flame at the end of safety time
Non-alterable lockout at the end of safety time, blink code 2
Loss of flame during operation
Factory setting:
Non-alterable lockout, blink code 7
Can be parameterized:
Max. 3 repetitions
Oil preheaters release contact does not close within 10
minutes
Non-alterable lockout, blink code 8
Release contact of the oil preheater opens 5 times during
prepurging
Non-alterable lockout
Table 5: Non-alterable lockout
In the event of a non-alterable lockout, the LMO remains locked and the red signal lamp
(LED) lights up permanently.
The burner control can immediately be reset. This state is also maintained in the event of
mains failure.
7.7 Resetting the burner control
After a non-alterable lockout, a reset can be carried out immediately.
Keep the lockout reset button depressed for about 1 second (<3 seconds). The
LMO39… can only be reset when all contacts in the line are closed and when there is
no undervoltage.
The burner control can also be reset via display and operation unit AZL2... or PC
software ACS410.
