Combustion Chamber Size; Combustion Checks; Burner Start-Up Cycle - Riello Two stage operation forced draught natural gas/propane burner Installation & Operating Manual

COMBUSTION CHAMBER SIZE

40
36
32
28
24
20
16
280 440
NOTES:
1) Sizes shown above are for cylindrical or wet base boilers, or air cooled heat exchangers.
2) To size the chamber in applications other than wet base boilers, you must calculate area in square inches of the
combustion zone required to give you a grate area or floor area to match the BTU inputs according to local authority.
3) Please consult local code requirements for combustion chamber construction and sizing.

COMBUSTION CHECKS

CO It is advisable not to exceed a measured reading of 10% CO² for Natural Gas or 12% CO² for Propane Gas taken
2
with the burner cover in place, to avoid the risk of the formation of CO due to minor changes in wind/draft
conditions which may occur.
CO For safety reasons, the value of .02% (200ppm) free air sample must not be exceeded.
IONIZATION CURRENT
The minimum amount of current necessary for
the control box to operate properly is 5 micro
Amps DC.
To measure the ionization current, disconnect
the red wire connector and insert a DC microme-
ter in series with control box terminal 2 and the
ionization probe, which senses the flame.

BURNER START-UP CYCLE

Normal
Thermostat
Motor
Ignition transformer
1 st stage valve
1 st stage flame
2 nd stage valve
2 nd stage flame
Lock-out
2s max.
When flame-failure occurs during working, shut down takes place within one second.
3245
COMBUSTION CHAMBER SIZE
Recommended Minimum Sizes
600 760
Control box
terminal block
3s max.
65s 10s
920 KBtu/h
Red wire connect
2
Lock-out, due to ignition failure
2s max. 65s
GB
Ionization probe
D5006
3s max.
D4170
12