IC 40 · Edition 07.18
16
t [s]
high
middle
low
closed
DI 1
t [s]
t
1
t
4
t
3
t
2
Function
3 .5 .2 2-point operation with flame proving period
Operating mode 2
In idle state (DI 1 with no signal), the actuator is in “low”
position (“low” position may also be 0° = “closed” posi-
tion).
If digital input DI 1 is activated, the actuator moves to
“middle” position within running time t
1
.
After waiting time t
2
, the actuator automatically moves
further to “high” position within running time t
3
.
As the voltage at digital input DI 1 drops, the actuator
closes to “low” position within running time t
4
.
DI 1
Position
Off
low/closed
On
high
If the signal at digital input DI 1 is deactivated before
“high” position is reached, the actuator moves directly to
“low” position within the percentage time of t
4
.
The actuator operates in high/middle/low (high/mid-
dle/closed) intermittent mode.
On burners which must ignite during opening of the
butterfly valve, waiting time t
2
is appropriate for flame
proving.
Possible parameter set for this operating mode:
P 68021, see page 45 (Parameter sets).
Operating mode 2