Burner Operation - Riello RS 44/M MZ Installation, Use And Maintenance Instructions

V2
V1
V3
(A)
V1
V3
(B)
NORMAL FIRING
(n° = seconds from istant 0)
NO FIRING

BURNER OPERATION

BURNER STARTING (A)
• 0s:
• 6s:
• 18s:
• 84s:
• 92s:
• 95s:
• 101s: Valves V1 and V3 open. The flame is
• 104s: The spark goes out.
• 113,5s:If the S3 switch commutes on the
• 135s: The control box starting cycle ends.
STEADY STATE OPERATION (A)
Burner without outputregulator RWF40
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
D9210
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 (D)p.10. 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 RWF40
See the handbook enclosed with the regulator.
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 104s after the closing of control
device TL.
The control box pilot light will light up.
BURNER FLAME GOES OUT DURING OPER-
D9211
ATION
If the flame should accidentally go out during
operation, the burner will lock out within 1s.
15
Load control TL closes.
Fan motor starts.
Servomotor starts:
90° rotation to right, until contact is
made on cam I (D)p.10.
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 (D)p.10 for MIN.
output.
The air gate valve and the gas butter-
fly are positioned to MIN. output with
cam III(D)p.10 at 15°.
Ignition electrode strikes a spark.
ignited, point A.
Position 1, the V2 valve opens with
relevant increase of the power (D).