Advertisement
Startup sequence (cont´d)
TSA
Ignition safety time
On completion of «TSA», a flame signal must be present at terminal 22. It must be available until controlled
shutdown occurs
→ otherwise, the burner control will initiate lockout and lock itself in the lockout position
t3n
Postignition time
-
«Z» must be connected to terminal 15
With short preignition, «Z» remains on until «TSA» has elapsed
-
→ connection to terminal 16
t4
Interval «BV1 – BV2» or «BV1 - LR»
On completion of «t4», voltage is present at terminal 19
-
-
The voltage is required to power «BV2» connected to auxiliary switch «v» in the actuator
t5
Interval
On completion of «t5», terminal 20 receives power. At the same time, control outputs 9 to 11 and input 8
-
are galvanically separated from the LAL...'s control section
→ LAL... is now protected against reverse voltages from the load control circuit
With the release of «LR» at terminal 20, the startup sequence of the LAL... ends
-
-
After a few idle steps (steps with no contact position changes), the sequence switch switches itself off
B
Operating position of the burner
B-C
Burner operation
During burner operation, «LR» drives the air damper to the nominal load or low-fire position, depending
-
on heat demand
-
Release of the nominal load takes place via auxiliary switch «v» in the actuator
-
In the event of loss of flame during operation, the LAL... will initiate lockout
For automatic start repetition, the clearly marked wire link «B» on the plug-in section of the LAL... must
-
be cut away
C
Controlled shutdown
In the case of controlled shutdown, «BV...» will immediately be closed. At the same time, the sequence
switch is started to program «t6».
C-D
Sequence switch travels to start position «A»
t6
Postpurge time
Fan «M2» connected to terminal 7
-
Shortly after the start of «t6», terminal 10 receives power
-
→ air damper is driven to the «MIN» position
Full closing of the air damper starts only shortly before «t6» has elapsed
-
→ initiated by the control signal at terminal 11
-
During the following burner off time, terminal 11 is live
t13
Permissible afterburn time
During «t13», the flame signal input may still receive a flame signal
→ no lockout
D-A
End of control program
→ start position
As soon as the sequence switch has reached the start position – having thereby switched itself off – the
flame detector and flame simulation test will start again.
During burner off times, the flame supervision circuit is live.
When the start position is reached:
With LAL1..., a voltage signals is fed to terminal 4
With LAL2... / LAL3... / LAL4..., a voltage signal is fed to terminal 12
10/20
Building Technologies
HVAC Products
CC1N7153en
20.04.2005
Advertisement
