689OccupationalSafetyandHealthAdmin.,Labor§1910.255switchshallbeinaccordancewithsub-partSofthispart.Overcurrentprotec-tionshallbeprovidedasspecifiedinsubpartSofthispart.Adisconnectswitchwithoverloadprotectionorequivalentdisconnectandprotectionmeans,permittedbysubpartSofthispart,shallbeprovidedforeachoutletintendedforconnectiontoaportableweldingmachine.(ii)Forindividualweldingmachines,theratedcurrent-carryingcapacityofthesupplyconductorsshallbenotlessthantheratedprimarycurrentoftheweldingmachines.(iii)Forgroupsofweldingmachines,theratedcurrent-carryingcapacityofconductorsmaybelessthanthesumoftheratedprimarycurrentsoftheweld-ingmachinessupplied.Theconductorratingshallbedeterminedineachcaseaccordingtothemachineloadingbasedontheusetobemadeofeachweldingmachineandtheallowancepermissibleintheeventthatalltheweldingma-chinessuppliedbytheconductorswillnotbeinuseatthesametime.(iv)Inoperationsinvolvingseveralweldersononestructure,d.c.weldingprocessrequirementsmayrequiretheuseofbothpolarities;orsupplycircuitlimitationsfora.c.weldingmayre-quiredistributionofmachinesamongthephasesofthesupplycircuit.Insuchcasesnoloadvoltagesbetweenelectrodeholderswillbe2timesnor-malind.c.or1,1.41,1.73,or2timesnormalona.c.machines.Similarvolt-agedifferenceswillexistifbotha.c.andd.c.weldingaredoneonthesamestructure.(A)Alld.c.machinesshallbecon-nectedwiththesamepolarity.(B)Alla.c.machinesshallbecon-nectedtothesamephaseofthesupplycircuitandwiththesameinstanta-neouspolarity.(d)Operationandmaintenance—(1)General.Workersassignedtooperateormaintainarcweldingequipmentshallbeacquaintedwiththerequirementsofthissectionandwith1910.252(a),(b),and(c)ofthispart.(2)Machinehookup.Beforestartingoperationsallconnectionstothema-chineshallbecheckedtomakecertaintheyareproperlymade.Theworkleadshallbefirmlyattachedtothework;magneticworkclampsshallbefreedfromadherentmetalparticlesofspat-teroncontactsurfaces.Coiledweldingcableshallbespreadoutbeforeusetoavoidseriousoverheatinganddamagetoinsulation.(3)Grounding.Groundingoftheweld-ingmachineframeshallbechecked.Specialattentionshallbegiventosafetygroundconnectionsofportablemachines.(4)Leaks.Thereshallbenoleaksofcoolingwater,shieldinggasorenginefuel.(5)Switches.Itshallbedeterminedthatproperswitchingequipmentforshuttingdownthemachineisprovided.(6)Manufacturers’instructions.Print-edrulesandinstructionscoveringop-erationofequipmentsuppliedbythemanufacturersshallbestrictlyfol-lowed.(7)Electrodeholders.Electrodehold-erswhennotinuseshallbesoplacedthattheycannotmakeelectricalcon-tactwithpersons,conductingobjects,fuelorcompressedgastanks.(8)Electricshock.Cableswithspliceswithin10feet(3m)oftheholdershallnotbeused.Theweldershouldnotcoilorloopweldingelectrodecablearoundpartsofhisbody.(9)Maintenance.(i)Theoperatorshouldreportanyequipmentdefectorsafetyhazardtohissupervisorandtheuseoftheequipmentshallbediscon-tinueduntilitssafetyhasbeenas-sured.Repairsshallbemadeonlybyqualifiedpersonnel.(ii)Machineswhichhavebecomewetshallbethoroughlydriedandtestedbeforebeingused.(iii)Cableswithdamagedinsulationorexposedbareconductorsshallbere-placed.Joininglengthsofworkandelectrodecablesshallbedonebytheuseofconnectingmeansspecificallyintendedforthepurpose.Thecon-nectingmeansshallhaveinsulationadequatefortheserviceconditions.[55FR13696,Apr.11,1990,asamendedat61FR9241,Mar.7,1996;70FR53929,Sept.13,2005]§1910.255R...
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