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8.4.8 Safe ESD reaction for “no seating” (no evaluation of limit and torque): check
This test is required for the following versions or configurations:
• Actuators with electromechanical control unit or actuator with electronic control unit and
limit switches.
• One of the following safety functions:
− Safe ESD function “Safe CLOSING” (Safe ESD in direction CLOSE)
− Safe ESD function “Safe OPENING” (Safe ESD in direction OPEN)
• Configuration of “SIL seating”
= “no seating”
(Safe OPENING or CLOSING without responding to any protective equipment).
For Safe ESD operation, the actuator has to perform the safety operation without interruption.
Limit switching and/or torque switching must not stop the safety operation
Since "SIL seating = no seating" (without end position protection) is configured, faulty
operation during the test may result in damage to the elements within the safety-
related system.
Possible consequences: Valve damage, motor overheating, contactor jamming, defective
thyristors, heating up or damage to cables.
→ Interrupt safety operation before reaching the end position (Set Safe ESDa and
Safe ESDb input signals to +24 V DC).
→ For the test, the valve should either be in mid-position or at sufficient distance from the
end positions.
→ In case of damage, the actuator system has to be checked and repaired, if necessary.
Fasten control cover screws and tighten glands at conduit entries.
20. Mechanical position indicator: The two dials have a slip clutch for easy adjustment.
At valve fully closed, turn dial (CLOSED) till the arrow is in alignment with the
mark on the show glass. Operate valve into fully OPEN position and adjust dial
marked (OPEN) till the arrow mark is in alignment with the mark on the cover.
The dial (CLOSED) must be held in position while adjusting dial (OPEN). (fig.19).
1. Operate actuator in mid-position or at sufficient distance from end positions.
2. Open the switch compartment.
3. Initiate safety operation:
® Set Safe ESDa and Safe ESDb input signals to 0 V (low).
Limit switching evaluation
4. Operate limit switches:
® For Safe CLOSING (Safe ESD in direction CLOSE) configuration: Turn test button
in direction of the LSC arrow.
® For "“Safe OPENING” (Safe ESD in direction OPEN) configuration: Turn test button
in direction of the LSO arrow.
Ø The safety function reaction to the limit switch signals is correct if safety operation is
not stopped.
5. After limit evaluation:
· Set Safe ESDa and Safe ESDb input signals to +24 V DC (high) before reaching
the end position.
· Operate actuator via local controls or from REMOTE to end position OPEN and
then to end position CLOSED. (Positions will be recorded anew).
· Operate actuator to mid-position or at sufficient distance from the end positions.
6. Close switch compartment.
NOTICE
Multi-turn actuators
SA series with Control 3.XX /NI/SIL
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