DIAGRAM OPERATION CONTINUOUS MODULATION
TC
PG
MB
PA
TR
V1ϒ
LR
RWF
max.
M
MT
min.
EC
Legend
T11 Air shutter opening time, from 0 to max.
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.
T10 Begins when the motor starts up and with the pre-
purge phase, within which the PA air pressure
switch must give the go-ahead.
T1
Pre-purge time.
T3
Pre-ignition phase, it ends when the gas valve
opens.
Input signals
Output signals
A
Begin start up
B
Flame present
B-C
Operation
C
Control stop
LR
Power regolator
C-D
Air shutter closure + post-purge
T10
TW
T11
T1
0
T3
T2
T12
T4
T2
Safety time, within which the flame signal must
reach the EC electrode.
T
Interval between the opening of the gas valve
and the opening of the second stage.
T6
Air shutter closing time and program zero-setting
time.
T12 Time in which the air shutter shifts to the start-up
position.
TC-PG
Thermostats/Gas pressure switch line
MB
Burner motor
PA
Air pressure switch
TR
Ignition transformer
VE
Gas valve
EC
Control electrode
MT
Air servo control
T6