Download - Electical risc of Water Cleaner
-
7/29/2019 Electical risc of Water Cleaner
1/12 Page1of11
Health and Safety
Executive
Electrical risks from steam/
water pressure cleanersGuidanceNotePM29
This is a free-to-download, web-friendly version of PM29
(First edition, published 2007). This version has been adapted for online use
from HSEs current printed version.
You can buy the document at www.hsebooks.co.uk and most goodbookshops.
ISBN 978 0 7176 0813 3
Price 4.00
This guidance gives advice on the installation, use and maintenance of
steam/water pressure cleaners and the use of this equipment kills people
every year. It identifies the electrical risks that can arise when using this
equipment and gives advice on safety precautions which will minimise these
risks.
The guidance is aimed at those who select or buy steam/water pressurecleaners, those who manage or supervise work where this type of equipment
is used and those who use it themselves.
HSE Books
-
7/29/2019 Electical risc of Water Cleaner
2/12Page2of11
Crown copyright 1995
Firstpublished1995
Reprinted1995,1999,2007
ISBN9780717608133
Allrightsreserved.Nopartofthispublicationmaybereproduced,storedin
aretrievalsystem,ortransmittedinanyformorbyanymeans(electronic,
mechanical,photocopying,recordingorotherwise)withoutthepriorwritten
permissionofthecopyrightowner.
Applicationsforreproductionshouldbemadeinwritingto:
TheOfficeofPublicSectorInformation,InformationPolicyTeam,
Kew,Richmond,SurreyTW94DUore-mail:[email protected]
ThisguidanceisissuedbytheHealthandSafetyExecutive.Followingtheguidanceisnotcompulsoryandyouarefreetotakeotheraction.Butifyoudofollowthe
guidanceyouwillnormallybedoingenoughtocomplywiththelaw.Healthand
safetyinspectorsseektosecurecompliancewiththelawandmayrefertothis
guidanceasillustratinggoodpractice.
Health and Safety
Executive
-
7/29/2019 Electical risc of Water Cleaner
3/12Page3of11
ContentsIntroduction 4
Equipmentdescription 4
Accidenthistory 4
Selectionofequipment 5
Useandmaintenance 9
Summaryoflegalrequirements 10
References 10
Furtherinformation 11
Health and Safety
Executive
-
7/29/2019 Electical risc of Water Cleaner
4/12Electricalrisksfromsteam/waterpressurecleaners Page4of11
Health and Safety
Executive
Introduction1 Thisguidancenotegivesadviceontheinstallation,useandmaintenanceof
steam/waterpressurecleaners.Useofthisequipmentkillspeopleeveryyear.The
electricalrisksthatcanarisewhenusingthisequipmentareidentified,andadviceis
givenonsafetyprecautionswhichwillminimisetheserisks.
2 Theguidanceisaimedatthosewhoselectorbuysteam/waterpressure
cleaners,thosewhomanageorsuperviseworkwherethistypeofequipmentis
used,andthosewhouseit.AnHSEleafletisalsoavailableINDG68(rev) Do you
use a steam/water pressure cleaner? You could be in for a shock!1
3 Adescriptionisgivenoftheequipmentandtheaccidentswhichitcancause,
andinformationisgivenonselection,aswellasinstallationanduse.Thisguidance
doesnotcoverthedesignoftheequipment.
Equipment description4 Steam/waterpressurecleanersareusedinmanyindustriesforavarietyof
differentpurposes.Atypicalmachineconsistsofatrolleymountedoil-firedboiler,
awatertankwithballvalve,adetergenttank,apumpdrivenbyanelectricmotor,
andalengthofreinforcedhosewithahandlanceattheend(seeFigure1).Thereis
usuallyahosesupplyingwatertothemachine,andonmovablemachines,aflexible
cablefortheelectricitysupply.Somemachinesomitthedetergenttankandclean
byahighpressurewaterjet,sometimeswithanaddedabrasive.Higherpressures
areusedforpaintandcorrosionremoval,whichmeansthatthesemachinesneedmorepowerfulpumpsandmotors.Mostmachinesspraywaterbasedsolutions,
butsomespraysolvents.
Accident history5 Theuseofthesemachineswillcreateawetenvironmentwheretheoperators
clothing,skinandfootweararelikelytogetwet.Ifanelectricalfaultoccurs,andthe
operatorreceivesanelectricshock,theseverityoftheshockwillbegreaterthanin
dryconditions,andwillbemorelikelytoresultindeathorseriousinjury.
6 Ananalysisofinvestigatedaccidentsoverthelastfiveyearsshowsthatin50%ofincidentstherewasafaultinthesupplycable,oranextensioncablewhereone
wasused.Typically,theearthwirebrokewhereitflexedmostoften.Wherethis
wasnotdetected,thenasecondwiringorinsulationfailureallowedexposedparts
oftheequipmenttobecomeliveatmainsvoltage.
7 Ingeneral,thistypeofequipmentisdesignedtobeusedwithallexposed
metalworkearthed.Thisisbecauseafaultsuchasaliveconductortouching
exposedmetalworkwillthencausethefusetoblow.In25%ofincidents
investigatedtheearthhadbecomedisconnectedfromtheexposedmetalwork.
Thisfaultwillnotbeimmediatelyobvioustotheuseroftheequipmentbutcanbe
detectedbyroutinemaintenance,forexampleinspectionandtesting.
8 In20%ofincidentsinvestigatedthewaterproofingoftheequipmentwas
inadequate,eitherbecauseofpoordesign,orlackofmaintenance.Theelectric
currentmaythenpassthroughthewaterandtheoperatortoearth.
-
7/29/2019 Electical risc of Water Cleaner
5/12Electricalrisksfromsteam/waterpressurecleaners Page5of11
Health and Safety
Executive
Selection of equipment
General
9 Itisimportantthatequipmentisselectedthatissuitableforthejob.Itshould
besufficientlywelldesignedandconstructedthatitissafewhenfirstputintouse,
andremainssafeduringtheforeseeableconditionsofitsuse.Whenconsidering
whetheranitemofequipmentwillbesuitable,youshouldalsoconsiderwhereitwill
beused,andwhatitwillbeusedfor.
10 Atinstallationswheretheelectricalequipmentmaybeusedoutdoors,andis
likelytobeusedclosetotheworksite,chooseequipment,wiringandconnectors
whichcankeepwaterout.Forexampleequipmentdesignedtobedrip-proofmay
bemarkedIP42;splashproofmaybemarkedIP43;andhoseproofequipmentmay
bemarkedIP56orIP57(inaccordancewithBSEN60529, 2thestandardcovering
waterprotection).Ingooddesigns,thecableentrieswillbesealed,andcableswillpreferablyenterfrombeloworbeprovidedwithrubbershroudsoreffectivegland
seals.Thiscanbespecifiedwhenequipmentisbeingselectedandinstalled.
11 Theriskofdamagetocablesandequipmentwillbereducedbyusingafixed
installationwhichhasbeendesignedforthepurpose.Thiswillalsoeliminatethe
needforplugs,socketsandothercableconnectionswhichmaygiverisetofaults
resultingindanger.Whereafixedinstallationisnotpracticable,thealternativeis
trolleyorsledgemountedequipment.
12 Asecureearthconnection,withthebondingofalllocallyexposedmetalworkto
thesameearthingpoint,isasimplewayofremovingthemostcommoncauseof
incidentsinvolvingthesemachines.Whereametalreinforcedhoseisfittedbetweenthelanceandthecleaner,themetalreinforcementandthelanceshouldbebonded
totheequipmentchassisandanyotherexposedmetalwork.
13 Theoperatorismorevulnerabletosevereelectricshockorelectrocutionin
Figure 1Steam/water
pressurecleaner-typical
application
-
7/29/2019 Electical risc of Water Cleaner
6/12Electricalrisksfromsteam/waterpressurecleaners Page6of11
Health and Safety
Executive
wetthanindryconditions.TheshockhazardisgreatlyreducedifReducedLow
Voltage(RLV)systemsareused,butthesesystemswillonlypowerthesmaller
designsofpressurecleaner.Onconstructionsites,110voltCentreTappedto
Earth(CTE)supplyisthemostcommonusedsystem,anditsuseisspreading
tootherindustries.ThefactthataRLCsystemisuseddoesnotmeanthatthe
standardsofwiringandinstallationcanberelaxed.
Fixed installations
14 Largerpressurisedwaterinstallationscanbedesignedsothatthepumpfeeds
apressurisedmainintowhichtheflexiblehosesforthelancescanbeplugged.
Thisallowstheelectricalapparatustobeseparatedfromthewetarea.
15 Supplycablestofixedinstallationsmayusesolidcoreconductors,anditis
recommendedthattheseareruninpermanentlyfixedconduittoughenoughto
protectthecablefromdamage,installedwheretheyareleastlikelytobedamaged.
Movable equipment
Cables
16 Solidcorecablesshouldnotbeusedtosupplymovableequipmentandshould
onlybeusedforfixedinstallations.(OrdinaryPVCinsulatedflexiblecablesarenot
generallysuitableforusewiththistypeofequipment.Theequipmentratingwill
definetheminimumcablesize,butfordurabilityitisrecommendedthatcables
haveaminimumcrosssectionof0.75squaremm(ratingof6Amps),andtough
rubbersheathed(TRS)outerinsulation).
17 Wheremovablepressurecleanersmaybeusedinanumberoflocations,
flexiblesupplycablesshouldnotbelefttrailingonthefloor,butshouldifpossible
besuspendedbyhooksorothermeans,andplacedwheretheyareleastlikelyto
bedamaged.Stressonthecableterminationsattheplugandatthemachinecan
bereducedbyprovidingadditionalcableclamps,orbytetheringthemachinetoa
fixedpointusingasubstantialchain.
18 Inareaswherecablesaremorelikelytobedamaged,forexampleinareas
wherevehiclesaremoving,extraprecautionswillbenecessary.Cablesmaybe
suspendedonacablebridge,orrunthroughsubstantialmetalpipessecured
againstbeingmovedbyvehicles.Alternatively,armouredcablescontaininga
braidedmetalsheathmaybeusedtoprotectagainstmechanicaldamage.Note,
however,thatsometypesofplugcannotbefittedtoanarmouredcable.
19 Armouringwillalsohelptoanchorthecable.Ifitiscorrectlyfittedatbothends,
andifitisearthed,mostformsofcabledamagewillresultinthefuseblowingor
otherprotectivedevicecuttingoffthepower.Cablearmouringwhichiscoatedin
plasticwillbeprotectedagainstabrasionandcorrosion.Acopper/nylonbraided
armouring,egasdescribedinAppendix2ofBS6708 3hasbeenshowntogivethe
longestlifeunderflexing.
20 Whennotinuse,itisrecommendedthatthecablesarestoredonpurpose-made
cablecarriers,preferablyfittedtothemachine.Remember,longcablesontightly
wounddrumsaresusceptibletooverheating,soitisessentialthatsuchcablesare
properlyselectedandusedinaccordancewiththemanufacturersinstructions.
Plugs and sockets
21 SquarepinorroundpindomestictypeplugsasshowninFigure2(a),egBS
13634orBS4565arenotrecommendedfortheindustrialenvironment.Indry,
indoorareas,goodqualityplugsandsockets(egBS196 6)shouldbeused,as
-
7/29/2019 Electical risc of Water Cleaner
7/12Electricalrisksfromsteam/waterpressurecleaners Page7of11
Health and Safety
Executive
showninFigure2(b).Plugsshouldhaveacordgripcapableofmaintainingafirm
holdonthecablesheath,andwhenwiringtheplug,itisrecommendedthatthe
earthwireismadelongerthantheothertwowiressothatitisnotthefirstwire
tobepulledoutifthecordgripfails.Insituationswherethecableissubjectto
considerableflexingwhereitenterstheplug,thecablecanbeprotectedatthis
pointwithaplasticsheathdesignedforthepurpose.
22 Inwetareasoroutdoors,plugsandsocketsshouldbedesignedtoprovide
adequateprotectionagainstwater,egBSEN60309 7connectorsmarkedIP44,
asshowninFigure2(c)forgeneraloutdooruse,orIP57withtheadditionalouter
sealingring,asshowninFigure2(d),forusewheretheycouldbesprayed.
Protection by residual current devices
23 MovableequipmentshouldbeprotectedbyaResidualCurrentDevice(RCD),
preferablyprovidedaspartofthefixedwiringinstallation.AnRCDworksby
detectingearthleakagecurrentsandswitchingoffthesupplyiftheleakagerises
abovetheratedtrippingcurrent.Suitablyfast-operatingandsensitivedevicesarenormallyreferredtoas30mA/30mSRCDs,andmaybeconnectedtoprotecta
numberofcircuits,orrestrictedtoonesocketoutlet.
Figure 2Plugsandsockets
Figure 2(a)Domestictypeplug.Lightduty,indoorsonly
-
7/29/2019 Electical risc of Water Cleaner
8/12Electricalrisksfromsteam/waterpressurecleaners Page8of11
Health and Safety
Executive
Figure 2(b)Industrialtype(BS196andderivatives).Heavyduty,indoors
Figure 2(c)Industrialtype(BSEN60309)
Heavyduty,indoors
Figure 2(d)Industrialtype(BSEN60309)
Heavyduty,hoseproof
-
7/29/2019 Electical risc of Water Cleaner
9/12Electricalrisksfromsteam/waterpressurecleaners Page9of11
Health and Safety
Executive
24 IncircumstanceswheretheRCDisnotprovidedaspartofthefixedinstallation,
theRCDshouldaccompanythemachineandshouldbeinstalledsothatitprotects
boththemachineandthesupplycable.Theuseofadaptertypeorplugtoptype
RCDsisnotrecommendedbecausetheseareoftenleftoutofuse,maynotbe
suitableforwetenvironments,ormaybeincorrectlyinstalled.
25 RCDsaresensitivedevicesandarefittedwithatestbuttonwhichwillneedto
beoperatedregularlytoensurethatthedevicestaysinworkingorder.RCDsare
notasubstituteforgoodinstallationpractice.
Circulating current earth monitoring
26 AsanalternativetoRCDprotection,thesystemmaybeprotectedbycirculating
currentearthprotection.Thissystemworksbycontinuouslyprovingtheintegrityof
theearthconductorbycirculatingasmallcurrentthroughit.Abreakinthiscircuit
operatesthetripmechanismanddisconnectsthesupply.Thistypeofprotectionis
particularlyrecommendedwheremovableequipmentisregularlyusedatalimited
numberoffixedlocations,forexampleinamotorvehiclecleaningarea.
Use and maintenance27 Carefullythoughtoutworkingpracticescangreatlyimprovesafety.The
operatorshouldbegiventraininginthesafeuseoftheequipment,andshouldbe
madeawareofthepotentialdangersarisingfromitsmisuse.Itisrecommended
thatmachinesareusedonlevelground,inawelldrainedarea.Inadditiontothe
electricalhazards,operatorswillneedtobeawareofthedangersfromspray
driftingintoadjacentworkareasorontomembersofthepublic.Highpressurejets
caninjectliquidsintothebodyandthiscanbeextremelydangerous.Responsiblesupervisionwillbenecessarytomakesurethatthesafeworkingproceduresare
followed.
28 Beforeusingthepressurecleanertocleanequipmentwhichhasanelectrical
supplyconnectedtoit,makesurethattheelectricitysupplytothesystemhas
beenisolated,andelectricalenclosureshavebeensealedtopreventwatergetting
in.Beforereconnectingthesupply,theequipmentmayneedtobeinspectedand
testedbyacompetentpersontoensurethatnodamagehasbeendoneduringthe
cleaningprocess.
29 Operatorsmayneedspecialclothingtoprotectthemfromtheliquidusedinthe
cleaner,andthematerialsonwhichitisbeingused.Itisstronglyrecommended
thatgogglesarewornwhentheequipmentisinuse,toprotecttheeyesfrommisdirectedsprays,orsuddenleaks.
30 Operatorsshouldchecktheequipmentvisuallybeforeeachuseoratthe
beginningofeachshiftifthemachinesareinconstantuse.Theyshouldbetrained
toidentifydamagetotheequipment,plugs,socketsandcable.Defectsshould be
reportedtoaresponsibleperson,andoperatorsmustneveruseamachinewhich
appearstobedefective.RCDsshouldalsobecheckedbyoperatingthetestbutton.
31 Inadditiontouserchecksacompetentpersonshouldcarryoutformalvisual
inspectionoftheequipmentandinstallationonaregularbasis,forexampleonce
perweekifitisindailyuse.
32 Sincecorrectearthingiscrucialtothesafeoperationoftheequipment,itis
stronglyrecommendedthatearthcontinuityandinsulationtestsarecarriedouton
themachineandthefixedinstallationwhentheequipmentisfirstinstalledandat
frequentintervalsthereafter.
-
7/29/2019 Electical risc of Water Cleaner
10/12Electricalrisksfromsteam/waterpressurecleaners Page10of11
Health and Safety
Executive
33 Itisrecommendedthattheearthcontinuityandinsulationresistanceofthe
equipmentistestedeverythreemonths.However,iftheequipmentisusedona
constructionsite,orasimilarworkplace,testseverymontharerecommended.
34 Testsofearthbondingofstructuralandothermetalworkinthevicinity,and
earthloopimpedanceatthesupplysocketsarerecommendedtobecarriedoutat
firstinstallationandatsixmonthstocheckfordeterioration.Acomparisonofthesix
monthreadingswiththosetakenattwelvemonthswillshowwhethertheinstallation
isdeterioratingfastenoughtorequiresixmonthtests.Ifthechangeinthereadings
islow,theinstallationmaybetestedattwelvemonthintervals.
35 Recordsofexaminations,testsandrepairsarenotrequiredbylaw,buttheywill
provideusefulinformationonthegeneralconditionofthemachineanditsrelevant
safetyfittings.FurtherguidanceonmaintenanceisgivenintheHSEguidance
bookletHSG107Maintaining portable and transportable electrical equipment.8
Summary of legal requirements36 Thefollowingsummaryoutlinesthemainlegalrequirementswhichapplytothe
useofsteam/watercleaners.Thelistisnotcompleteanddoesnotgiveadefinitive
interpretationofthelawitsummarisesthemainissuestobeborneinmindwhen
usingthisequipment.Fulldetailsofthelegislationcanbefoundinthedocuments
referredtoattheendofthisguidancenote.
37 TheHealthandSafetyatWorketcAct19749placesdutiesonemployers,
employeesandtheself-employedtoensure,sofarasisreasonablypracticable,the
safetyofpeopleinvolvedinworkactivities,andthosewhomaybeaffectedbyworkactivities.
38 TheManagementofHealthandSafetyatWorkRegulations199910require
employersandtheself-employedtoassesstherisksarisingfromworkactivities,
andtocontroltheseriskssothattheyarereducedtoanacceptablelevel.
39 TheElectricityatWorkRegulations198911requirepeopleincontrolofpartorall
ofanelectricalsystemtoensurethatitissafetouse,andthatitismaintainedina
safecondition.
40 Section6oftheHealthandSafetyatWorketcAct1974andtheSupplyof
Machinery(Safety)Regulations1992 12placedutiesonmanufacturersandsuppliers
ofmachineryandequipmentforuseatwork,andrequirethatmachineryandequipmentissuppliedinasafecondition.
41 TheControlofSubstancesHazardoustoHealth(COSHH)Regulations2002
(asamended)13andthePersonalProtectiveEquipmentatWorkRegulations1992 14
mayapplywheretheliquidusedinthecleaner,orthematerialsonwhichitisbeing
usedcouldcauseahazardtohealth.
References1 Do you use a steam/water pressure cleaner? You could be in for a shock!LeafletINDG68(rev)HSEBooks1997(singlecopyfree)Webversion:
www.hse.gov.uk/pubns/indg68.pdf
-
7/29/2019 Electical risc of Water Cleaner
11/12Electricalrisksfromsteam/waterpressurecleaners Page11of11
Health and Safety
Executive
2 BSEN60529:1992Specification for degrees of protection provided by
enclosuresBritishStandardsInstitution
3 BS6708:1998Flexible cables for use at mines and quarriesBritishStandards
Institution
4 BS136313A plugs, socket-outlets and adaptorsBritishStandardsInstitution
Part1:1995Specification for rewirable and non-rewirable 13A fused plugs
Part2:1995Specification for 13A switched and unswitched socket outlets
5 BS546:1950Specification for two pole and earthing pin plugs, socket outlets
and socket outlet adaptersBritishStandardsInstitution
6 BS196:1961Specification for protected type non-reversible plugs, socket
outlets, cable couplers and appliance couplers, with earthing contacts for single
phase AC circuits up to 250 voltsBritishStandardsInstitution
7 BSEN60309Plugs, socket-outlets and couplers for industrial purposes
BritishStandardsInstitution
Part1:1999General requirements
Part2:1999Dimensional interchangeability requirements for pin and contact-tube
accessories
8 Maintaining portable and transportable electrical equipment(Secondedition)
HSG107HSEBooksISBN0717628051
9 Health and Safety at Work etc Act 1974 (c.37)TheStationeryOffice
ISBN0105437743
10 Management of health and safety at work. Management of Health and Safety
at Work Regulations 1999. Approved Code of Practice and guidanceL21(Second
edition)HSEBooks2000ISBN0717624889
11 Electricity at Work Regulations 1989SI1989/635TheStationeryOffice1989
ISBN011096635X.Alsoavailable, Memorandum of guidance on the Electricity at
Work Regulations 1989. Guidance on RegulationsHSR25HSEBooks1989
ISBN0717616029
12 Supply of Machinery (Safety) Regulations 1992SI1992/3073TheStationery
Office1992ISBN0110257197
13 Control of substances hazardous to health (Fifth edition). The Control ofSubstances Hazardous to Health Regulations 2002 (as amended). Approved Codes
of Practice and guidanceL5(Fifthedition)HSEBooks2005ISBN0717629813
14 Personal protective equipment at work (Second edition). Personal Protective
Equipment at Work Regulations 1992 (as amended). Guidance on RegulationsL25
(Secondedition)HSEBooks2005ISBN0717661393
Whileeveryefforthasbeenmadetoensuretheaccuracyofthereferenceslistedin
thispublication,theirfutureavailabilitycannotbeguaranteed.
-
7/29/2019 Electical risc of Water Cleaner
12/12
Further informationForinformationabouthealthandsafetyringHSEsInfolineTel:08453450055
Fax:08454089566Textphone:08454089577e-mail:[email protected]
writetoHSEInformationServices,CaerphillyBusinessPark,CaerphillyCF833GG.
HSEpricedandfreepublicationscanbeviewedonlineororderedfrom
www.hse.gov.ukorcontactHSEBooks,POBox1999,Sudbury,Suffolk
CO102WATel:01787881165Fax:01787313995.HSEpricedpublications
arealsoavailablefrombookshops.
BritishStandardscanbeobtainedinPDForhardcopyformatsfromtheBSIonline
shop:www.bsigroup.com/ShoporbycontactingBSICustomerServicesforhard
copiesonlyTel:02089969001e-mail:[email protected].
TheStationeryOfficepublicationsareavailablefromTheStationeryOffice,POBox29,NorwichNR31GNTel:08706005522Fax:08706005533
e-mail:[email protected]:www.tso.co.uk(Theyarealso
availablefrombookshops.)StatutoryInstrumentscanbeviewedfreeofcharge
atwww.opsi.gov.uk.
Published by HSE 03/10 Page 11 of 11
Health and Safety
Executive