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Building Technologies CC1N7153en
HVAC Products 20.04.2005
Function (cont´d)
-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... / LAL4..., 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 preheater’s temperature
-Normally closed contact of the air pressure switch must be closed →«LP» test
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... / LAL4...:
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... / LAL4...
«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
Flame supervision
Preconditions for
burner startup
With the exception of LAL1...