Electical risc of Water Cleaner

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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


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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


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ContentsIntroduction 4

Equipmentdescription 4

Accidenthistory 4

Selectionofequipment 5

Useandmaintenance 9

Summaryoflegalrequirements 10

References 10

Furtherinformation 11

Health and Safety

Executive


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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.



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



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



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



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



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.



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



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.


12/12

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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.

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