Minimum Gas Pressure Switch; Burner Firing - Riello RS 190/M Installation, Use And Maintenance Instructions

5.6.3

Minimum gas pressure switch

The purpose of the minimum gas pressure switch is to prevent the
burner from operating in an unsuitable way due to too low gas pres-
sure.
Adjust the minimum gas pressure switch (Fig. 42) after having ad-
justed the burner, the gas valves and the gas train stabiliser. With
the burner operating at maximum output:
– install a pressure gauge downstream of the gas train stabiliser
(for example at the gas pressure test point on the burner com-
bustion head);
– choke slowly the manual gas cock until the pressure gauge de-
tects a decrease in the pressure read of about 0.1 kPa
(1 mbar). In this phase, verify the CO value which must always
be less than 100 mg/kWh (93 ppm).
– Increase the adjustment of the gas pressure switch until it inter-
venes, causing the burner shutdown;
– remove the pressure gauge and close the cock of the gas pres-
sure test point used for the measurement;
– open completely the manual gas cock.
1 kPa = 10 mbar
WARNING
5.7

Burner firing

Having completed the checks indicated in the previous heading,
the pilot of the burner should fire.
If the motor starts but the flame does not appear and the flame
safeguard goes into lock-out, reset and wait for a new firing at-
tempt.
Pilot adjustment has been illustrated on page 17.
Having adjusted the pilot, reconnect the main valve
and ignite the main flame; it might require several
attempts to purge the air from the gas lines or to ad-
just the valve with little gas.
WARNING
Once the burner has fired, now proceed with calibration operations.
20160742
Start-up, calibration and operation of the burner
30
D9290
GB
Fig. 42