Riello RL 800/M FS2, Installation, Use And Maintenance Instructions

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Start-up, calibration and operation of the burner
6.8 Operation sequence of the burner
Legend (Fig. 31 and Fig. 32)
MV - Fan motor
MP - Pump motor
SM - Servomotor
TA - Ignition transformer
TL - Limit thermostat/pressure switch
TR - Adjustment thermostat/pressure
Y - Light oil valves
6.8.1 Steady state operation

Burner without output regulator RWF40
At the end of the starting cycle, the servomotor control then pass-
es to the thermostat/pressure switch TR for boiler pressure or
temperature point C (Fig. 31).
(The control box continues, however, to check that the flame is
present and that the air pressure switch is in the correct position).
–
If the temperature or pressure is low (and the thermostat/
pressure switch TR is consequently closed), the burner pro-
gressively increases its output to the MAX. value, (section C-
D).
– If subsequently the temperature or pressure increases until
thermostat/pressure switch TR opens, the burner progres-
sively decreases its output to the MIN. value (section E-F).
And so on.
– The burner locks out when demand for heat is less than the
heat supplied by the burner at min. output (section G-H).
Thermostat/pressure switch TL opens. The servomotor re-
turns to the 0° angle limited by contact with cam 2).
The gate valve closes completely to reduce thermal disper-
sion to a minimum.
Every time output is changed, the servomotor automatically mod-
ifies the fuel delivery, air delivery (fan gate valve) and air pressure
(2 shutters in the combustion head).

Burner with output regulator RWF40
See the handbook enclosed with the regulator.
6.8.2 Undesired shutdown during operation
If the flame should accidentally go out during operation, the burn-
er will lock out within 1s.
6.8.3 Firing failure
If the burner does not fire, it goes into lock-out within (Fig. 32) 3
s of the opening of the gas solenoid valve and 119 s after the
closing of control device TL.
TL
TR
MV
SM
MP
TA
VS VF VR VRS
Fig. 31
NORMAL FIRING
D11108
VS VRS VR VF
TL
TR
MV
SM
MP
TA
Fig. 32
D11109
FIRING FAILURE