Operation Sequence Of The Burner; Burner Start-Up; Operation; Ignition Failure - Riello RS 810/M BLU Modulating Operation

6.8

Operation sequence of the burner

6.8.1

Burner start-up

0s TL thermostat/pressure switch closure.
6s Fan motor start. Servomotor starts: rotates 90° towards
the right, i.e. until the intervention of the contact on the
cam I).
38s The air damper is positioned to MAX output.
38s Pre-purging phase with air delivery of the MAX output.
Duration 32 seconds.
70s The servomotor rotates left up to the angle set on the
cam II).
102s The air damper and the gas butterfly valve set to MIN
output (with cam II).
103s Ignition electrode strikes a spark.
109s The VS safety valve and the VR adjustment valve open
(rapid opening). The flame is ignited at a low output lev-
el, point A (Fig. 35). There follows a progressive in-
crease of the input, slow opening of the valve, up to the
MIN output, point B (Fig. 35).
112s The spark goes out.
133s The starting cycle ends.
6.8.2

Operation

Burner without the RWF... output regulator (See kit)
Once the start-up cycle is completed, the servomotor command
moves on to the TR thermostat/pressure switch that controls the
pressure or the temperature in the boiler, point C. (The electrical
control box continues to check the presence of the flame and the
correct position of the air and gas maximum pressure switches).
– If the temperature or the pressure is low so the thermostat/
pressure switch TR is closed, the burner progressively in-
creases the output up to the MAX value (section C-D).
– If subsequently the temperature or pressure increases until
TR opens, the burner progressively decreases its output to
the MIN value (section E-F). The sequence repeats endless-
ly.
– The burner locks out when the heat request is less than the
heat supplied by the burner at MIN output, (section G-H). The
TL thermostat/pressure switch opens, and the servomotor re-
turns to angle 0° limited by the contact of the cam 2)(Fig. 31
on page 25).
The air damper closes completely to reduce heat losses to a
minimum.
For every change of output, the servomotor will automatically
change the gas output (butterfly valve), the air output (fan damp-
er) and the air pressure.
Burner with the RWF ... output regulator (See kit)
See manual enclosed with the adjuster.
6.8.3

Ignition failure

If the burner does not fire (Fig. 36), it goes into lockout within 3
sec. after the gas valve opens, 112 seconds after the control de-
vice TL closes and the pre-purging phase starts and lasts 17 sec-
onds.
20163413
Start-up, calibration and operation of the burner
6.8.4

Burner flame goes out during operation

If the flame should go out during operation, the burner will lockout
within 1s.
(n° = seconds from instant 0)
M
VS
VR
M
M
VS
VR
M
28 GB
Normal ignition
Ignition failure
20156672
Fig. 35
20156673
Fig. 36