Spectrex 40/40I Triple IR (IR3) Flame Detector - Manual (Page 77)

40/40I Flame Detector 65
E SIL-2 Features
➣ In this appendix…
40/40I Flame Detector page 65
E.1 40/40I Flame Detector
This appendix details the special conditions to comply with the requirements
of EN 61508 for SIL 2.
The 40/40I Flame Detector can only be used in low or high demand mode
applications, 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: 3.0 x 10 -4 (≈ 3% of SIL-2) if only Alarm Relay is used for
alerting.
 PFD: 3.2 x 10 -4 (≈ 3.2% of SIL-2) if 0-20mA – interface is used as
alarm.
 PFH: 1.5 x 10 –7 1/h (≈ 14.9% of SIL-2) for 0-20mA application.
 SFF: 95% fulfills the conditions of EN 61508 for SIL2
 Alternative 2: Functional check of the detector every 365 days:
 HFT: 0
 PFD: 4.5 x 10 -4 (≈ 4.5% of SIL-2) if only Alarm Relay is used for
alerting.
 PFD: 4.9 x 10 -4 (≈ 4.9% of SIL-2) if 0-20mA – interface is used
signal current as alarm.
 PFH: 1.5 x 10 –7 1/h (≈ 14.9% of SIL-2) for 0-20mA application.
 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