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Multi-turn actuators
SA .1 with AC 01.2-22X/-22Y/ACExC 01.2-22X/-22Y
4.3.
Safe inputs and outputs
4.4.
Redundant system architecture
Information
Safe STOP function: safe STOP
-
An operation command of standard actuator controls (in directions OPEN
or CLOSE) will only be executed if an additional enable signal for the op-
eration command is present.
-
If this is not the case, operation in directions OPEN or CLOSE is stopped
or even suspended (motor is switched off).
-
The Safe STOP function is effective for all operation commands of the
standard actuator controls, irrespective of the command source (e.g. Re-
mote or Local).
Safe ESD function combined with Safe STOP function
-
Safe ESD function has a higher priority i.e. if both functions are activated,
the actuator is operated into the configured direction (OPEN/CLOSE).
22Y version only: "Safe end position feedback"
-
An end position signal directly wired to the actuator is available. The safety
function is the correct signal whether the actuator is in the requested actu-
ator end position or not.
path is safety related. End position feedback via I/O interface relay or a
positioner (RWG, MWG, potentiometer, ...) or via a fieldbus interface does
not represent a safe end position feedback.
The different configuration options of the safety functions are described in the
<Configuration (setting)/version> chapter.
Safe input for safe OPENING/CLOSING (Safe ESD function):
Safe ESDa
Safe ESDb
Safe inputs for safe stop (Safe STOP function):
Safe STOP OPEN
Safe STOP CLOSE
Safe outputs (indication that it might not be possible to perform the safety function):
SIL failure
SIL ready
For detailed information on safe inputs and outputs, refer to <Configuration
(setting)/version> chapter and <Installation> chapter.
Besides the already described typical safety instrumented system including an
actuator, safety can be increased by implementing a second, redundant valve and
actuator with actuator controls in 22X or 22Y version into the safety instrumented
system. The decision on the appropriate version depends on the entire system.
Depending on the safety function and the safety instrumented task of this safety
function, it must be verified for each and every application whether and
which configuration a HFT>0 can be actually achieved when using several actuators.
This applies in particular
A possible example for Safe CLOSING or Safe OPENING is shown in figure 3 and
4. Another example, in which several actuators do not achieve redundancy, is a
Safe STOP function used to safely exclude the movement of mechanical system
parts, if, for example, the fire brigade has to access the plant section in question in
case of an emergency. For this application, use of two actuators does generally not
result in a 1oo2 but in a 2oo2 system in terms of safety effect to be achieved.
Therefore, the HFT is not increased in this case.
3)
Please note that safety figures only include the components of the actuator. Further components
(e.g. integrity of external controls, gearboxes, valve shaft, other valve components....) are not
considered with the AUMA safety figures related to this product.
Safety instrumented system and safety functions
3)
Only the signal via this signal communication
but is not limited to
the Safe STOP safety function.
if so
in
13
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