FLAME FAILURE & SEQUENCE CONTROL – Siemens LAL.1 Burner Control
The unit is designed to provide control and supervision for atomising oil burners of medium to large capacity. They
are suitable for use on multi-stage and modulating burners.
For safety reasons, at least one controlled shutdown must be provided within each 24-hour period of continuous
operation.
When a burner failure is encountered the box goes into lockout mode. This is indicated by an orange neon, which
displays within the lockout window of the control and is repeated at the lockout lamp on the panel facia.
If a lockout situation occurs, the burner will not start until it is manually reset by pressing the lockout window on the
control. (The control can also be reset by the off/on reset switch situated on the control panel facia).
If the burner fails to fire and persists in locking out,
no more than three attempts should be made
. To do so will
almost certainly create a
dangerous situation
.
If a burner becomes troublesome then the assistance of a qualified engineer should be obtained. To assist in his
diagnosis, notes should be made detailing the events leading up to the lockout situation. The symbol appearing in the
lockout window should also be noted prior to re-setting the burner.
(Refer to the Sequence Diagram and Timing Chart
below)
.
PLEASE NOTE:
When the control box goes to lockout it is generally performing the function it is designed for.
Burner Control Program
Burner operated sequence based on the Siemens LAL1.25 Control Box. Note: Timings are for operation on a 50Hz
electrical supply only.
MOL 3400-4100 Issue 2 10/08
Page 27
t6
Burner
Motor
Air
Damper
Ignition
Main Oil
Valves
Flame On
t2 t3
t4
t5
t7
t1 t8
Ts
Run Tp
T
Period
Time
(secs)
Description
t1
2.5
Start-up time for fan motor
t2
5
Start-up to ‘open’ signal
t3
54
Modulating servo to ‘High Flame’
t4
22.5
Full air pre-purge
t5
54
Modulating servo to ‘Low Flame’
t6 54
Pre-ignition
t7 5
Safety
period
t8
15
Release to RWF 40 Controller
Ts
155.5 Total start-up time
Tp
15
Post purge time
T
170.5 Control re-cycle time
