Burkert Type 8791 - Manual (Page 25)

25
Technical Data
8.7. safety positions after failure of the electrical or
pneumatic auxiliary power
The safety position depends on the fluid connection of the actuator to the working connections A1 or A2.
actuator system Designation
safety positions after failure of the
electrical auxiliary power
pneumatic
auxiliary power
up
down
single-acting
Control function
A
down
→
Connection according to “Figure 6”
down
up
→
Connection according to “Figure 7”
up
down
single-acting
control function
B
up
→
Connection according to “Figure 6”
up
down
→
Connection according to “Figure 7”
up
down
lower
chamber
upper
chamber
double-acting
Control function
I
→
Fluid connection see “Figure 8”
not defined up = lower chamber of the actuator to A2
down = upper chamber of the actuator to A2
Table 4: Safety Positions
fluid connection: Description for “Table 4”
single-acting actuators
Control function A and B Double-acting actuators
Control function I
Connection:
working connection A1 to actuator
A2 sealing
Connection:
working connection A2 to actuator
A1 sealing
Connection:
Working connection A1 and A2
to actuator
Safety position:
up = lower chamber to A2
down = upper chamber to A2
Figure 6: Connection A1 Figure 7: Connection A2 Figure 8: Connection with CFI
english
Type 8791