Combustion Adjustment; Ionisation Current; Air Pressure Switch - Riello 40 Installation, Use And Maintenance Instructions

COMBUSTION ADJUSTMENT

In conformity with Efficiency Directive 92/42/EEC, the application of the burner on the boiler,
adjustment and testing must be carried out by observing the instruction manual of the boiler,
including verification of the CO and CO
the average temperature of the water in the boiler. It is advisable to set the burner according to
the type of gas used and following the indications of the table:
EN 676
Theoretical max. CO
GAS
0 % O
G 20 11.7
G 25 11.5
G 30 14.0
G 31 13.7

IONISATION CURRENT

The minimum current necessary for con-
trol box operation is 5 μA.
The burner normally supplies a higher cur-
rent value, so that no check is needed.
Should you want to measure the ionisation
current anyway, you must open the con-
nector (CN1), (see wiring diagram page 5) inserted in the red wire and insert a microammeter.

AIR PRESSURE SWITCH

The air pressure switch is set after all other burner adjustments
have been made. Begin with the air pressure switch to the start of
the scale. With the burner operating at the required power, turn
the knob slowly in a clockwise direction until burner lockout.
Then turn the knob anticlockwise to an extent that is around 20%
of the adjusted value and then check that the burner starts up
properly. If the burner locks out again turn the knob slightly in an
anticlockwise direction.
Warning:
In conformity with the standard, the air pressure switch must pre-
vent the air pressure falling below 80% of the adjusted value and
the CO in the flue gases exceeding 1% (10,000 ppm). To check
this, insert a combustion analyser in the flue, slowly reduce the
suction inlet of the fan (for example with a piece of cardboard)
and verify that the burner locks out before the CO value in the
flue gases exceeds 1%.
3389
concentration in the flue gases, their temperatures and
2
AIR EXCESS: max. power   1.2 – min. power   1.3
Setting CO
2
 = 1.2
2
9.7
9.5
11.6
11.4
%
2
 = 1.3
9.0
8.8
10.7
10.5
D4625
Control
box socket
7
GB
NO
CO
mg/kWh
mg/kWh
 100  170
 100  170
 100  230
 100  230
Connector
_
+
D7404
x
Probe