OPERATING CYCLE
LMG 25 CONTROL BOX
TW Begins with the closure of the thermostatic
line or the PG. The PA must be in the rest
position. This is the waiting and self-test time
lasting for 9 seconds.
T10 Begins when the motor starts up and with the
pre-purge phase; it lasts for 3 seconds, within
which the PA air pressure switch must give the
go-ahead.
Necessary input signals
Output signals
A
Begin start up
B
Flame present
Operation
B-C
C
Control stop
C-D
Air gate closure + post-purge
ARIA
AIR
T1
Pre-purge time, which lasts for at least 30
seconds, ending when the transformer starts up.
Pre-ignition phase, it ends when the gas valve
T3
opens, and it lasts for 3 seconds.
T2
Safety time, within which the flame signal must
reach the EC electrode; it lasts for 3 seconds.
TC-PG
Thermostats/Gas pressure switch line
Burner motor
MB
PA
Air pressure switch
TR
Ignition transformer
Gas valve
V
EC
Control electrode
40