ELECTRIC EQUIPMENT
OIL BURNER CONTROL: LOA21... / LOA24...
WITH PREHEATER
OUTER ELECTRICAL CONNECTION
X1
X2
FUNCTION
1.
Switch on operating switch and twin thermostat
Voltage is applied to the preheater and the preheating period starts. This
period lasts till the operating temperature of the oil has been reached
and the preheater thermostat closes (2).
2.
Preheater thermostat closes
The burner motor starts, an ignition spark is formed, the prepurge goes
on till the prepurge period expires and the solenoid valve opens (3).
3.
Solenoid valve opens
Oil mist is formed and ignited. The photocell indicates a flame.
(1)
The ignition spark goes out 15 s. after flame indication
(LOA24.171...)
.
(2)
The ignition spark goes out 2 s. after flame indication when the ignition
transformer is connected to terminal 7
(LOA24.173...)
.
4.
The safety time expires
a. If no flame is established before this time limit the control cuts out.
b. If for some reasons the flame disappears after this time limit, the
burner will make an attempt to re-start.
4-5.
Operating position
If the burner operation is interrupted by means of the main switch or the
thermostat, a new start takes place when the conditions in accordance
with point 1 are fulfilled.
The oil burner control cuts out
A red lamp in the control is lit. Press the reset button and the burner
re-starts.
Post-ignition
(2)
If a post-ignition of 15 s. is wanted, move the ignition transformer from
terminal 7 to terminal 6
(LOA24.173...)
.
LIST OF COMPONENTS
A1 Oil burner control
P1 Time meter (optional)
A2 Twin thermostat
R1 Photoresistor
E1 Preheater
S3 Main switch
F1 Fuse, max. 10A
T1
Ignition transformer
H1 Alarm lamp
Y1 Solenoid valve
H2 Signal lamp (optional)
X1
Plug-in contact, burner
M1 Burner motor
X2
Plug-in contact, boiler
The colours of the preheater cable:
A Blue
B Brown
C Black
Mains connection and fuses in accordance with local regulations.
TECHNICAL DATA
Pre-ignition time:
13 s
Pre-purge time:
13 s
(1)
Post-ignition time:
15 s
(2)
Post-ignition time:
2 s
Safety lock-out time:
10 s
Reset time after lockout:
≈
50 s
Reaction time on flame failure:
max. 1 s
Ambient temperature:
from - 20 to + 60°C
Min. current with flame established:
65 µ A
Max. photo current at start:
5 µ A
Enclosure:
IP 40
(Under voltage proof only LOA24...)
CONTROL OF PHOTO CURRENT
Current through photo unit is measured with a d.c. ammeter (a moving coil instrument
connected in series with the photo unit).
171 415 21 04-01
WIRING DIAGRAM
* If there is no plug-in contact (X2) on the boiler,
connect to the contact enclosed. In case the
twin thermostat is in series on incoming phase
L1, a loop between the terminals T1 and T2 is
necessary.
*
(1)(2)
