20096088
36
GB
Start-up, calibration and operation of the burner
5.10 Steady state operation
At the end of the starting cycle, the servo-motor control then pass-
es to load control for boiler pressure or temperature.
If the temperature or pressure is low (and the load control is
consequently closed), the burner progressively increases out-
put up to MAX.
If subsequently the temperature or pressure increases until
the load control opens, the burner progressively decreases
output down to MIN.
The burner shuts off when demand for heat is less than the
heat supplied by the burner in the MIN output.
The servomotor returns to the 0° angle limited by contact with
cam 2. The air damper closes completely to reduce thermal
dispersion to a minimum.
Every time output is changed, the servomotor automatically modi-
fies oil delivery (pressure regulator) and air delivery (fan damper).
5.11 Firing failure
If the burner does not fire, it goes into lock-out within 3 sec. of
the opening of the light oil valve.
If the flame should go out for accidental reasons during opera-
tion, the burner will lock out in 1 s.
5.12 Flame signal measurement
Check the flame signal through the parameter 954, as indicated in
Fig. 50. The displayed value is expressed in percentage.
The value during the operation must be higher than 24%. If at the
burner start-up the value is higher or equal of 18%, the burner locks
out due to the extraneous light.
For further and specific information, please refer to the specific in-
struction manual.
The display (Fig. 50) shows parameter
954
: flashing on the left.
On the right, the flame’s intensity is displayed as a percentage.
Example:
954: 0.0
5.13 Final checks (with the burner working)
Tab. P
S8171
P
V
h
min s
%
Fig. 50
Open the control limit operation
Open the high limit operation
The burner must stop
Rotate the maximum gas pressure switch knob to the mini-
mum end-of-scale position
Rotate the air pressure switch knob to the maximum end of
scale position
Rotate the maximum oil pressure switch at the minimum of
the scale
The burner must stop in lockout
Switch off the burner and disconnect the voltage
Disconnect the minimum gas pressure switch
Rotate the minimum low oil pressure switch at the maximum
of the scale
The burner must not start
Cover the UV flame sensor
The burner must stop in lockout due to firing failure
WARNING
Make sure that the mechanical locking systems on
the different adjustment devices are fully tightened.
