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Control sequence under fault conditions and lockout indication
The symbol appearing above the reading mark indicates the type of fault:
No start
=
Interruption of
startup sequence
Lockout
P
Lockout
>
Interruption of
startup sequence
Lockout
1
Lockout
I
Lockout indicator
Building Technologies Division
In case of any disturbance, the supply of fuel will immediately be interrupted.
Whenever a fault occurs, the sequence switch stops and with it the lockout indicator.
One of the contacts is not closed (also refer to «Preconditions for burner startup»)
Extraneous light:
Lockout during or after completion of the control program
Examples:
– Nonextinguished flame
– Leaking fuel valves
– Faulty flame supervision circuit
No «OPEN» signal at terminal 8 from the end switch «a»
Terminals 6, 7 and 15 are live until fault has been corrected
Does not apply to LAL1:
No air pressure indication at the beginning of the air pressure check
Air pressure failure after the air pressure check
Defect in the flame supervision circuit
No positioning signal at terminal 8 from the auxiliary switch «m» for the low-fire
position
Terminals 6, 7 and 15 are live until fault has been corrected
No flame signal at the end of the safety time «TSA»
Flame signal has been lost during operation
After the lockout reset, the burner control sequence switch first returns to the start
position and then initiates a burner restart.
If lockout occurs any other moment in time between start and preignition not indicated
by a symbol, the usual cause is a premature flame signal, that is, a faulty flame signal
caused, for instance, by extraneous light.
LAL1
Burner control can immediately be reset after lockout:
– Do not press the lockout reset button for more than 10 seconds
The sequence switch always travels to the start position first
– After resetting
– After rectification of a fault that led to shutdown
– After each power failure
During this period of time, power is only fed to terminals 7 and 9...11.
Then, the burner control will program a new burner startup sequence
Note!
Do not press the lockout reset button for more than 10 seconds.
a-b
b-b´
b (b´)-a Postpurge program
LAL2, LAL3
Startup sequence
Idle steps
(with no contact confirmation)
CC1N7153en
21.09.2016
15/24
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