Safety Manual SIL KFD2-ST*4-(Ex)*, KFD2-CR4-(Ex)*
Proof Test
2014-09
15
4 Proof Test
4.1 Proof Test Procedure
According to IEC 61508-2 a recurring proof test shall be undertaken to reveal
potentially dangerous failures that are otherwise not detected by diagnostic tests.
The functionality of the subsystem must be verified at periodic intervals
depending on the applied PFD
avg
in accordance with the data provided in this
manual. See chapter 2.4.
It is under the responsibility of the operator to define the type of proof test and the
interval time period.
With the following instructions a proof test can be performed which will reveal
almost all of the possible dangerous faults (diagnostic coverage > 90 %).
The ancillary equipment required:
• Digital multimeter with an accuracy better than 0.1 %
For the proof test of the intrinsic safety side of the devices, a special
digital multimeter for intrinsically safe circuits must be used.
Intrinsically safe circuits that were operated with non-intrinsically
safe circuits may not be used as intrinsically safe circuits
afterwards.
• Power supply set at nominal voltage of 24 V DC
• Process calibrator with mA current source/sink feature (accuracy better
than 20 µA)
The entire measuring loop must be put out of service and the process held in
safe condition by means of other measures.
Prepare a test set-up for testing the devices (view Figures). Choose the
proper input terminals (passive input or active input) in accordance with the
specific application and follow the steps indicated in the table below.
Restore the safety loop. Any by-pass of the safety function must be removed.
Safety Manual SIL KFD2-ST*4-(Ex)*, KFD2-CR4-(Ex)*
www.acornfiresecurity.com
www.acornfiresecurity.com
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