IC 40 · Edition 07.18
43
t [s]
high
low
closed
DI 1
Power
t [s]
t
1
t
2
t
S
Function
3 .6 .8 Emergency closing function
The emergency closing function cuts in in the event of
a fault or interruption of the continuous supply voltage
(power) or, for instance, in the event of a motor defect.
A pre-tensioned spiral spring turns the drive shaft with
valve disc to the “closed” position within the closing
time t
S
< 1 s.
Fast and reliable closing prevents air being able to flow
into the furnace or kiln chamber in uncontrolled man-
ner if the installation is disconnected from the electri-
cal power supply or in the event of a device defect. The
penetration of air may also lead to damage to the ma-
terial in the furnace or kiln in extreme cases, besides
changing the furnace or kiln atmosphere.
In order to maximize the service life of the parts subject
to wear in the actuator and in the butterfly valve, the
emergency closing function should be used only for the
intended closing function and not for controlled shut-
down or for intermittent switching of the burner.
The emergency closing function is available as an op-
tion on the actuator IC 40S and can be implemented
only in combination with the butterfly valve BVHS. Both
actuator and butterfly valve must feature this function,
see page 59 (Selection).
Emergency closing function