32
UK
OPERATING CYCLE
M
Necessary input signals
Output signals
A
Begin start up
B
Flame present
B-C
Operation
C
Control stop
C-D
Air shutter c post-purge
TC-PG
Thermostats/Gas pressure switch line
MB
Burner motor
MT
Air servo control
PA
Air pressure switch
TR
Ignition transformer
V1-V2
1
st
/2
nd
stage gas valve
EC
Control electrode
TMF
Modulation thermostat
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; it lasts for 3 seconds, within
which the PA air pressure switch must give the go-ahead.
T1
Pre-purge time, which lasts for at least 30 seconds, ending when the transformer starts up.
T3
Pre-ignition phase, it ends when the gas valve opens. It lasts for 3 seconds.
T2
Safety time, within which the flame signal must reach the EC electrode. It lasts for 3 seconds.
T4
Interval between the opening of the V1 gas valve and the opening of the second stage V2. It lasts
for 8 seconds.
T5
Air shutter closing time and program zerosetting time.
T12
Time in which the air shutter shifts to the start-up position.
