Spectrex 40/40M Multi IR Flame Detector - Manual (Page 77)

40/40M Flame Detector 65
E SIL-2 Features
➣ In this appendix…
40/40M Flame Detector page 65
E.1 40/40M Flame Detector
This appendix details the special conditions to comply with the requirements
of EN 61508 for SIL 2.
The 40/40M 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: 3.3 x 10 -4 (≈ 3.3% 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 as
alarm.
 PFH: 1.6 x 10 –7 1 /
h
(≈ 16.4% 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: 5.1 x 10 -4 (≈ 5.1% of SIL-2) if only Alarm Relay is used for
alerting.
 PFD: 5.6 x 10 -4 (≈ 5.6% of SIL-2) if 0-20mA interface is used.
 PFH: 1.6 x 10 –7 1 /
h
(≈ 16.4% 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