GB 4776

GB4776-84:1984-11-111.1fail-safe1.2nromalcondition1.3electricaccident1.4electricshock1.5injuryduetoelectromagneticfield1.6disruptivedischargedielectricbreakdown1.7shortcircuit1.8insulationfault1.9earthfault1.10overcurrent1.11overvoltage1.12overload1.13conductivepart1.14livepart(PEN)1.15exposedconductivepart1.16extraneousconductivepart()1.17simultaneouslyaccessibleparts1.18directcontact1.19indirectcontact1.20touchvoltage1.21stepvoltage1.22safetyextra-lowvoltage(SELV)501.23voltagetoearth()1.24overvoltagetoearth()1.25shockcurrent1.26()thresholdofperceptioncurrent1.27()thresholdoflet-gocurrent1.28()thresholdofventricularfibrillationcurrent1.29faultcurrent1.30()overloadcurrent(ofacircuit)1.31short-circuitcurrent1.32residualcurrent1.33totalimpedanceofthehumanbody\=1.34safetyimpedance1.35faultwithstandability1.36unsafetemperature()22.12.1.1()insulation(property)2.1.2()insulation(material)2.1.3insulationsystem2.1.4basicinsulation2.1.5supplementaryinsulation2.1.6doubleinsulation2.1.7reinforcedinsulation2.1.8insulationresistance2.1.9dielectricstrenght2.1.10dielectrictest2.1.11leakagecurrent2.1.12dielectricloss2.1.13()lossangle(undersinusoidalcondition)2.1.14Qqualityfactor2.1.15enclosure2.1.16protectivecover2.1.17barrier2.1.18obstacle2.22.2.1clearance2.2.2protectivegap2.2.3creepagedistance2.2.4toisolatea.b.()2.2.5safedistance2.2.6armsreach2.32.3.1()()(continuous)current-carryingcapacity(ofaconductor)2.42.4.1safetymarking2.4.2supplementarymarking2.4.3safetycolour33.13.1.1TNTNsystemTNa.TN-Sb.TN-C-Sc.TN-CTNSC1A.1B.1C.3.1.2TTTTsystemTT23.1.3ITITsystemIT33.1.4systemwitheffectivelyearthedneutral3¦X0/X1¦=31R0/X1=13.1.5systemwithnon-effectivelyearthedneutral3X0/X131R0/X113.23.2.1inspectionearthing3.2.2workingearthing3.2.3protectiveearthing3.2.4iterativeearth3.2.5faultearthing“”3.2.6resistanceofanearthedconductorearthingresistance3.2.7earthfaultcurrent()()3.2.8earthfaultcurrent3.2.9earthshortcircuitcurrent3.2.10()overcurrentprotection3.2.11()overvoltageprotection3.2.12open-phaseprotection3.2.13protectionagainstdirectcontact;protectionagainstshockinnormalservice,basicprotection3.2.14protectionagainstindirectcontact;protectionagainstshockinthecaseofafault;supplementaryprotection3.2.15equipotentialbonding3.2.16dust-protected3.2.17protectedagainstsplashing3.2.18protectedagainstdroppingwater3.2.19protectedagainsttheeffectsofimmersion3.2.20protectedagainstsubmersion“”3.33.3.1safetycircuitanddevice3.3.20class0equipment()3.3.3classequipment()3.3.4classequipment()3.3.5classequipment3.3.6()overcurrentprotectivedevice3.3.7()release(ofamechanicalswitchingdevice)3.3.8protectiverelay3.3.9()(single-phaseneutral)earthingreactor3.3.10earthedcircuit3.3.11earthingswitch()3.3.12earthingconductor3.3.13mainearthingterminalmainearthingbar()3.3.14residualcurrentcircuit-breaker3.3.15interlockingdevice3.3.16arc-controldevice3.3.17safetyisolatingtransformer3.3.18circuit-breaker()