Eaton PBI Technical Manual

4 Call point pBi/BGi & pBW/BGW February 2024 www.eaton.comCall point PBI/BGI & PBW/BGWEnglish8.0 Functional safety - PBIntroductionThe PB Call Point has been designed for use in potentiallyexplosive atmospheres and harsh environmentalconditions. The glass reinforced polyester enclosures aresuitable for use offshore or onshore, where light weightcombined with corrosion resistance is required.The function of the call point is to raise an alarm manuallyonce verification of a fire or emergency condition exists,by pushing the button.The safety function of the PB Call Point is to raise thealarm when the Button is pressed.Under No fault (Normal) Operating conditions the PB PushButton Unit will raise the alarm upon operating the switchvia pushing the button.Under fault conditions the failure mode of the PushButton is a failure to raise the alarm. For the failure rateassociated with this failure mode please refer to the tablebelow.Assessment of functional safetyThe PB Call Point is intended for use in a safety systemconforming to the requirements of IEC61508.UL has conducted a Failure Modes Effect and DiagnosticAnalysis (FMEDA) of the PB Push Button unit against therequirements of IEC61508-2 using a proof test interval of8760hrs. The results are shown below and are based onRoute 1H.The Call Point is classed as a Type A device.pB 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 valueConditions of safe useThe following conditions apply to the installation,operation and maintenance of the assessed equipment.Failure 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 userdocumentation.3. All information associated with any field failuresof this product should be collected under adependability management process (e.g., IEC60300-3-2) and reported to the manufacturer.4. The unit should be tested at regular intervals toidentify any malfunctions; in accordance with thissafety manual.