Appendix 1.1: Possible Proof Tests To Detect Dangerous Undetected Faults - turck IM1-12-R Handbuch

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Appendix 1.1: Possible proof tests to detect dangerous undetected faults

The proof test consists of the following steps, as described in Table 11.
Table 11 Steps for Proof Test
Step Action
1 Take appropriate action to avoid a false trip
2 Provide NAMUR control signals to the Isolating Switching Amplifier to open/close the
output and verify that the output is open/closed.
3 Restore the loop to full operation
4 Restore normal operation
This test will detect more than 90% of possible "du" failures of the Isolating Switching Amplifier.
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