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Function (cont´d)
Flame supervision
Preconditions for
burner startup
With the exception of LAL1...
Startup sequence
A
Start command by «R»
«R» closes the start control loop between terminals 4 and 5
The sequence switch starts to run
-
- Only prepurging, fan motor at terminal 6 receives power
- Pre- and postpurging, fan motor or flue gas fan at terminal 7 receives power on completion of «t7»
-
On completion of «t16», the control command for opening the air damper is delivered via terminal 9
-
Terminal 8 receives no power during the positioning time
The sequence switch continues to run only after the air damper has fully closed
-
t1
Prepurge time with air damper fully open
-
The correct functioning of the flame supervision circuit is checked during «t1»
-
The burner control will initiate lockout if correct functioning is not ensured
With LAL2... / LAL3...:
Shortly after the beginning of «t1», the air pressure switch must change over from terminal 13 to terminal 14
otherwise, the burner control will initiate lockout
start of the air pressure check
t3
Short preignition time
«Z» must be connected to terminal 16, release of fuel via terminal 18.
t3´
Long preignition time
«Z» connected to terminal 15.
With LAL1...
«Z» is switched on when start command is given.
With LAL2... / LAL3...
«Z» is switched on when «LP» changes over.
no later than at the end of «t10»
On completion of «t1», the LAL... drives the air damper to the low-fire position via terminal 10
-
the low-fire position is defined by the changeover point of auxiliary switch «m» in the actuator
-
During the positioning time, the sequence switch maintains its position
until terminal 8 receives power via «m»
The motor of the sequence switch is switched to the control section of the LAL...
-
positioning signals delivered to terminals 8 now have no impact on the further startup sequence and
on subsequent burner operation
10/19
Building Technologies Division
Infrastructure & Cities Sector
Flame detector and flame simulation test are made automatically during burner off
-
times and the prepurge time «t1»
-
If loss of flame occurs during operation, the burner control will initiate lockout
If automatic repetition of the startup sequence is required, the clearly marked wire
-
link on the plug-in section of the LAL... must be cut away start repetition
-
Burner control is not in the lockout position
-
Sequence switch is in its start position
with LAL1..., voltage is present at terminals 4 and 11
with LAL2... / LAL3..., voltage is present at terminals 11 and 12
Air damper is closed
-
End switch «z» for the «CLOSED» position must feed power from terminal 11 to
-
terminal 8
-
Contact of the limit thermostat or pressure switch «W» and the contacts of any
other switching devices in the control loop between terminals 4 and 5 must be
closed e.g. a control contact for the oil preheaters temperature
Normally closed contact of the air pressure switch must be closed «LP» test
-
CC1N7153en
23.05.2014
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