Eaton BG Technical Manual

Contents

7Call points BG/pB Ex E VErsions TM244 May 2019 www.eaton.comCall points BG/PB Ex e VersionsEnglishAssessment of functional safetyThe PB Call Point is intended for use in a safety systemconforming to the requirements of IEC61508 UL hasconducted a Failure Modes Effect and DiagnosticAnalysis (FMEDA) of the PB Push Button unit against therequirements of IEC61508-2 using a proof test intervalof 8760hrsThe results are shown below and are based on Route 1HThe Call Point is classed as a Type A devicepB pushbuttonSafety Function of PB Push Button:‘To raise the alarm upon pushing the button’Architecturalconstraints: Type AHFT=0SFF= 79.7%Proof Test Interval=8760HrsMTTR = 8 HrsSIL2Random hardwarefailures: λDD = 0λDU = 3.43E-08 λSD = 0λSU = 1.34E-07Probability of failureon demand: PFDAVG=1.50E-04(Low Demand Mode) SIL3Probability ofDangerous failure onsafety function:PFH = 3.43E-08(High Demand Mode) SIL3Hardware safetyintegrity compliance[1] Route 1HSystematic safetyintegrity compliance Route 1SSystematic Capability SC2Overall SIL-capabilityachieved SIL 2 (Low Demand)*SIL 2 (High Demand)**Limited to SIL 2 due to SFF value0.00000.00200.00400.00600.00800.01000.01200.01400 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60 63 66 69 72 75PFD (avg)Time (years)PBProof Time Interval versus SIL contributionSIL 2 à cause de contraintes d'architecture (SFF)Conditions of safe useThe following conditions apply to the installation,operation and maintenance of the assessed equipmentFailure to observe these may compromise the safetyintegrity of the assessed equipment:1 The user shall comply with the requirements given inthe manufacturer’s user documentation (This SafetyManual and Technical manual) in regard to all relevantfunctional safety aspects such as application of use,installation, operation, maintenance, proof tests,maximum ratings, environmental conditions, repair, etc;2 Selection of this equipment for use in safety functionsand the installation, configuration, overall validation,maintenance and repair shall only be carried out bycompetent personnel, observing all the manufacturer’sconditions and recommendations in the userdocumentation3 All information associated with any field failures ofthis product should be collected under a dependabilitymanagement process (e g , IEC 60300-3-2) andreported to the manufacturer4 The unit should be tested at regular intervals to identifyany malfunctions; in accordance with this safety manual