AUMA SA3 - Proof Test (Verification of Safe Actuator Function)

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Conditions and required settings:
− Additional non-interacting end position switches for safe and reliable end position
feedback signals are available and wired to the safety PLC.
− A digital input of standard controls (galvanically separated from the other inputs) is
configured to the following value:
− The safety PLC directly controls the PVST or will also receive the control signal if the
PVST input is controlled.
− The PVST may only be performed from one of the end positions.
− Parameter must amount to > 4 seconds. PVST operating time
− Signals and of the standard controls are sent via digital PVST fault PVST abort
outputs (galvanically separated from the other outputs) of the standard controls to the
safety PLC.
PVST is either directly requested at the PVST input of the standard controls by the safety PLC
or the signal for requesting the PVST is also sent to the safety PLC. While the 3.XX /NI
standard controls perform the PVST, the safety PLC monitors whether
− the actuator was in one of the end positions prior to the PVST (check via safe end
position feedback).
− the actuator left one of the end positions within the set PVST operation time (check via
safe end position feedback).
− If a fault was signaled via the SIL output contact (SIL module: SIL failure).
Only if the actuator was in one of the end positions prior to the PVST, has left this end position
during the PVST, the standard controls have neither issued a nor a PVST fault PVST
abort signal from standard controls, nor the SIL module signaled a SIL fault, was the
PVST was successfully completed. If this is not the case the device has to be checked in
accordance with the steps in the <Proof test> chapter.
Information
If digital inputs or outputs of standard controls are connected to the safety PLC, imperatively
ensure sufficient absence of interference of all non-safety-related system components with
regard to the safety function. The absence of interference must be guaranteed even in case
of standard component faults. For this, galvanic isolation between safety-related and non
safety-related system components is important (but not necessarily sufficient).
Performing a PVST includes diagnostics of the safety-related components. This ensures
improved safety figures compared to applications without or with minor diagnostics.
8.4 Proof test (verification of safe actuator function)
The proof test serves the purpose to verify the safety-related functions of the actuator and
actuator controls.
Proof tests shall reveal dangerous faults which might be undetected until a safety function is
started and consequently result in a potential danger.
Information
During execution of the proof test, the safety function is unavailable for a short time.
Depending on both version and configuration, the proof test includes the following
tests:
1. Check Safe ESD safety operation (Safe OPENING/CLOSING).
2. Check SIL fault signal “Actuator monitoring”.
3. Check Safe ESD reaction for “Motor protection (thermal fault)” signals
4. Check Safe ESD reaction to “Limit seating with overload protection” (limit and/or torque
evaluation).
5. Check Safe ESD reaction to “Forced limit seating in end position” (limit evaluation) –
for actuators with electromechanical control unit.
Multi-turn actuators
SA series with Control 3.XX /NI/SIL