Bentone BENTOFLEX ST 120 KA, Installation And Maintenance Instruction

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Bentone  

7.2  List of components

A1  Oil burner control

A2  Twin thermostat

F1  Fuse, max. 10A

H1  Alarm lamp

H2  Signal lamp (optional)

M1  Burner motor

P1  Time meter (optional)

R1  Flame detector

S3  Main switch

T1  Ignition transformer

Y1  Solenoid valve

X1  Plug-in contact, burner

X2  Plug-in contact, boiler

If S6 is missing connection between 

T6 and T8. Mains connection 

and fuse in accordance with local 

regulations

Control of photo current

The current through photo unit is 

measured with a d.c. ammeter (a 

moving coil instrument connected in 

series with the photo unit).

7.2.1  Function LOA

1

1. Switch on operating switch and twin thermostat

The burner motor starts, an ignition spark is formed, the prepurge 

goes on till the prepurge period expires and the solenoid valve 1 

opens (2)

2.

Solenoid valve 1 opens

Oil mist is formed and ignited. The photocell indicates a flame. 

3.

a

b

The safety time expires

If no flame is established before this time limit the control cuts out.

If for some reasons the flame disappears after this time limit, the 

burner will make an attempt to re-start.

4

Full load thermostat ON

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...). The burner is in operating position and can now 

change between high and low capacity.

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...).

Technical data oil burner control

LOA

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:

< 1 s

Ambient temperature:

-20 - +60°C

Min. current with flame established:

65 µA

Max. photo current at start:

5 µA