3350
12
GB
4.6
OPERATING PROGRAMME
4.6.1 NORMAL OPERATION
t
3
t
4i
t
s
t
4L
TL
M
I
V
SO
LED
LED
P
M
.
t
1
SO
t
2
t
3b
t
3a
KEY TO LAY-OUT
I
– Ignition transformer
LED
– Reset button LED indicating operating
status
M
– Fan motor
SO
– Ionisation probe
TL
– Limit thermostat
V
– Gas valve
t1
Standby time pending an input signal to control box:
reaction time, the control box stands still for the time
t1
.
t3I
Flame or flame simulation detected during pre-purging:
immediate lockout.
t1I
Flame or flame simulation detected before demand for
heat:
if the presence of light lasts for the
t1l
time, a lockout fol-
lows.
ts
Safety time:
if no flame is detected by the end of time
ts
the cycle
(start-up) is repeated and lockout occurs after 3
attempts to restart.
t2
Standby time after a request for heat:
the control box stays still for the
t2
time.
t4i
Transformer ignition time:
total ignition time.
t2I
Flame or flame simulation detected during standby time:
lockout occurs if flame or flame simulation persists for
time
t2l
.
t4I
Flame loss in operation:
valve drop maximum reaction time, lockout occurs after
3 recycle attempts.
t3
Pre-purging time:
start of the fan motor.
t6
Post-purging time:
additional purging time on the opening of the heat limit
thermostat (
TL
).
t3a
Purging check at maximum rpm from 12th to 20th sec-
ond of pre-purging.
t6I
Flame or flame simulation detected during post-purging:
lockout occurs if flame or flame simulation persists for
time
t6l
.
t3b
Purging check at START rpm from 35th to 40th second
of pre-purging.
D7252
MV = still
Flame loss during operation (Recycle max 3 attempts)
Lockout
Red (LED lights)
Green (LED lights)
No signal needs to be received
Purging motor at max. rpm
Purging motor at START rpm
Green
Green
Red
OPERATING TIMES
Time expressed in seconds
t1
t1I
t2
t2l
t3
t3a
t3b
t3l
ts
t4i
t4l
t6
t6l
max
max
-
max
-
-
-
max
-
-
max
max
max
1
30
3
30
40
8
5
1
3
3
1
360
30
(t3b)
