Spectrex 40/40R - Single IR Flame Detector - Manual (Page 73)

40/40R Optical Flame Detector 61
E SIL-2 Features
In this appendix…
40/40R Optical Flame Detector page 61
E.1 40/40R Optical Flame Detector
This appendix details the special conditions to comply with the requirements
of EN 61508 for SIL-2.
The SharpEye 40/40R shall only be used in low demand mode application,
see IEC 61508.4, Chapter 3.5.12.
E.1.1 Safety Relevant Parameters
Perform the following functional checks of the detector:
• Alternative 1: Functional check of the detector every 180 days:
• HFT: 0
• PFD: 2.4 x 10
-4 (≈ 2.4% of SIL-2) if only Alarm Relay is used for
alerting.
• PFD: 2.6 x 10 -4 (≈ 2.6% of SIL-2) if 0-20mA interface is used.
• SFF: 95% fulfills the conditions of EN 61508 for SIL2
• Alternative 2: Functional check of the detector every 365 days:
• HFT: 0
• PFD: 3.2 x 10
-4 (≈ 3.2% of SIL-2) if only Alarm Relay is used for
alerting.
• PFD: 3.6 x 10 -4 (≈ 3.6% of SIL-2) if 0-20mA interface is used to
signal current as alarm.
• SFF: 95% fulfills the conditions of EN 61508 for SIL2
E.1.2 Guidelines for Configuring, Installing, Operating and
Service
The alert conditions according to SIL 2 can be implemented by an:
• Alert signal via 20mA current loop
or
• Alert signal via alarm relay and the fault relay