Burner Operation - Riello RS 25/M BLU FS2 Installation, Use And Maintenance Instructions

STANDARD IGNITION
(n° = seconds from the moment 0)
(A)
(B)
In the event of a burner lockout, more than two consecutive burner reset opera-
tions could cause damage to the installation. On the third lockout, contact the Af-
tersales Service.
If further lockouts or burner faults occur, interventions must only be made by
qualified, authorised personnel (as indicated in this manual, and in compliance
with the laws and regulations currently in force).
Do not press the reset button or the remote reset button of the control box for
more than 10 seconds because this will damage the internal relay.
IGNITION FAILURE

BURNER OPERATION

BURNER STARTING (A)
• 0s:
• 6s:
• 30s:
• 61s:
• 81s:
• 84s:
• 90s:
• 93s:
• 114s: The control box starting cycle ends.
STEADY STATE OPERATION (A)
D798
Burner without outputregulator RWF
At the end of the starting cycle, the servomotor
control then passes to the load control TR for
boiler pressure or temperature, point C.
(The LFL control box continues, however, to
check that the flame is present and that the air
and gas max. pressure switches are in the cor-
rect position.)
• If the temperature or pressure is low (and the
TR load control is consequently closed), the
burner progressively increases its output to
the MAX. value, (section C-D).
• If subsequently the temperature or pressure
increases until 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).
Load control TL opens. The servomotor
returns to the 0° angle limited by contact with
cam II (E)p.12. The gate valve closes com-
pletely to reduce thermal dispersion to a mini-
mum.
Every time output is changed, the servomotor
automatically modifies gas delivery (gas butter-
fly valve) and air delivery (fan gate valve).
Burner with output regulator RWF
See the handbook enclosed with the regulator.
D799
FIRING FAILURE (B)
If the burner does not fire, it goes into lock-out
within 3s of the opening of the gas solenoid
valve and 93s after the closing of control device
TL.
The control box pilot light will light up.
BURNER FLAME GOES OUT DURING OPER-
ATION
If the flame should accidentally go out during
operation, the burner will lock out within 1s.
14
Load control TL closes.
Fan motor starts.
Servomotor starts:
90° rotation to right, until contact is
made on cam I (E)p.12.
The air gate valve is positioned to
MAX. output.
Pre-purge stage with air delivery at
MAX. output.
Duration 31 seconds.
Servomotor rotates to left up to the
angle set on cam III (E)p.12 for MIN.
output.
The air gate valve and the gas butter-
fly are positioned to MIN. output with
cam III(E)p.12 at 15°.
Ignition electrode strikes a spark.
Safety valve VS and adjustment valve
VR (rapid opening) open. The flame is
ignited at a low output level, point A.
Delivery is then progressively
increased, with the valve VR opening
slowly up to MIN. output, point B.
The spark goes out.