AUMA SA3 - 3 Architecture, Configuration and Applications; Architecture (Actuator Sizing)

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3 Architecture, configuration and applications
3.1 Architecture (actuator sizing)
For actuator architecture (actuator sizing) the maximum torques, run torques and operating
times are taken into consideration.
Incorrect actuator architecture can lead to device damage within the safety- related
system!
Possible consequences can be valve damage, motor overheating, contactor jamming,
defective thyristors, heating up of cables or damage to cables.
→ The actuator technical data must imperatively be observed when selecting the
actuator.
→ Sufficient reserves have to be provided to ensure that actuators are capable of reliably
opening or closing the valve even in the event of an accident or under- voltage.
Architecture when using the Safe STOP function
Information
For the Safe STOP function, the motor is switched off, overrun may possibly occur!
Valve damage due to overrun!
→ For the Safe STOP function (SS), the overrun of the arrangement (actuator, gearbox,
valve) and the reaction time have to be observed.
→ If the application requires self-locking of the actuator, please consult AUMA.
Architecture when using the Safe STOP function
Actuators with electromechanical control unit:
For end position signaling (limit switching) and torque signaling via the electromechanical
control unit are safe signals which may be integrated into a safety-related system. However,
this signal is not part of the certification by TÜV Nord. Please refer to the specific safety
manual for details regarding this signal.
For “SIL seating” = “no seating” (without end position protection), we recommend:
• To prevent valve damage during safety operation, we recommend, depending on the
stiffness, sizing the valve to 3 – 5 times the maximum actuator torque.
• To avoid thermal damage due to excessive currents, we recommend monitoring
(assessing) the motor protection.
Actuators with electronic control unit MWG:
Information
For end position signaling (limit switching) and torque signaling via the electronic control unit
MWG are not considered as safe signals.
• In case safe signals are required, they have to be implemented differently, e.g. using
switches on the valve.
• To prevent valve damage during safety operation, we recommend, depending on the
stiffness, sizing the valve to 3 – 5 times the maximum actuator torque.
• To avoid thermal damage due to excessive currents, we recommend monitoring
(assessing) the motor protection.
NOTICE
NOTICE
Multi-turn actuators
SA series with Control 3.XX /NI/SIL