Control Sequence In The Event Of Fault; Lockout; Lockout And Control Sequence Indication - Siemens LGB21.130A17 Datasheet

Control sequence in
the event of fault

Lockout

Resetting the LGB...

Lockout and control sequence indication

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In principle, whenever lockout occurs, the fuel supply will immediately be shut down. If
that takes place between startup and preignition, which is not indicated by a symbol,
the usual cause is air pressure switch «LP» shutting down, or a premature, faulty flame
signal.
• After a mains failure or in the event of un-
dervoltage:
• Premature flame signal from the start of «t1»: Immediate lockout
• Contacts of air pressure switch «LP» have
welded during «tw»:
• No air pressure signal:
• Air pressure failure on completion of «t10»:
• Burner does not ignite:
• Flame is lost during operation:
After lockout, the LGB... will remain locked (lockout cannot be changed).
This state will also be maintained in the event of mains voltage failure.
Whenever lockout occurs, the burner control can immediately be reset.
The position of the programming mechanism can be seen through the viewing window
on the front of the unit. In the event of fault, the programming mechanism stops and
thus the lockout indicator also. The symbol in the viewing window indicates both the
position in the control sequence and the type of fault according to the following legend:
No startup since the start control loop is open
Interval «tw» or «t10» (LGB21...)
IIII
Interval «tw» or «t11» (LGB22... / LGB32...)
Interval «tw», «t3» or «TSA» (LGB41...)
Air damper fully open (LGB22... / LGB32...)
Lockout due to absence of air pressure signal
P
Interval «t1», «t3» and «TSA» (LGB21...)
Interval «t1», «t3» («t12») (LGB22... / LGB32...)
Release of fuel
Lockout since there is no flame signal on completion of the first safety time
1
Release of second fuel valve (LGB21... / LGB41...)
2
Release of load controller (LGB22... / LGB32...)
Lockout since there is no flame signal on completion of the second safety time
3
(LGB41...)
Partial load or nominal load operation (or return to the operating position)
New startup with full program sequence
on power restoration
Prevention of startup
Lockout on completion of «t10»
Immediate lockout
Lockout on completion of «TSA»
Immediate lockout
13/22
CC1N7435en
11.01.2007