Diploma Unit C Q&A

8/18/2019 Diploma Unit C Q&A

1/50

1

NEBOSH Level 6 Diploma

in OSH

Unit C Questions & Answers


2/50

2

(a) Outline a range of hazards associated

with the use of mobile elevating work

platforms (MEWPs). ()

(b) Outline the general re!uirements for

the safe use of MEWPs. (")


3/50

a! Ha"ar#s woul# in$lu#e% 'alls 'rom t(e wor)in* plat'orm o' persons or

materials+ insta,ilit- o' t(e ve(i$le+ ,e$ause o' su$( 'a$tors as

usin* t(e .E/0 on uneven *roun#+ or outri**ersnot ,ein* eten#e# properl-

(e .E/0 ,ein* stru$) ,- ot(er ve(i$les+ trappin* o' part o' t(e ,o#- in t(e li'tin* ma$(iner-

o' t(e .E/0+

0e#estrians ,ein* stru$) ,- t(e .E/0+ me$(ani$al 'ailure o' t(e .E/0+ leavin* wor)ers

stran#e# at (ei*(t+ $onta$t wit( over(ea# power lines or ot(er

o,stru$tions a#verse weat(er $on#itions su$( as (i*( win#lea#in* to overturnin* o' t(e ve(i$le+ or wor)ersepose# to etremel- (ot or $ol# weat(er an#e$essive U3 'rom sunli*(t4


4/50

5

,! eneral re7uirements woul# in$lu#e%a! (e sele$tion an# trainin* o' operators8

,! *uar#in* s$issor me$(anisms to prevent trappin*8

$! $orre$t positionin* to prevent over9rea$(in* an# proimit-to #an*ers su$( as over(ea# lines8

#! maintainin* sta,ilit- ,- t(e use o' 'ull- eten#e# an#lo$)e# outri**ers on 'irm *roun#8

e! preventin* t(e use o' t(e e7uipment in a#verse weat(er$on#itions8

'! )eepin* wit(in t(e sa'e wor)in* limit :S/L! o' t(e .E/08

*! pro(i,itin* t(e trans'er o' persons or materials to or 'romt(e plat'orm w(ile it was in a raise# position8

(! re*ular inspe$tion an# servi$in* o' t(e e7uipment8i! preventin* 'alls 'rom t(e plat'orm ,- t(e use o' (an# rails

an# (arnesses8

;! $ontrollin* wor)in* areas ,- t(e use o' ,arriers an# si*ns

an# provi#in* (ea# prote$tion w(ere appropriate4


5/50

<

Outline the process that must be followed before

a machine can be supplied under the #uppl$

of Machiner$ (#afet$) %egulations &''. :1=!


6/50

6

Un#er t(e Suppl- o' .a$(iner- >e*ulations 1??2+ t(e ma$(inemust satis'- $ertain Essential Healt( an# Sa'et- >e7uirements:EHS>s! an# must ,e sa'e 'or t(e inten#e# use4

EHS>s $over 'a$tors su$( as t(e sa'et- an# relia,ilit- o' $ontrol

#evi$es+ prote$tion a*ainst me$(ani$al (a"ar#s an# ot(er(a"ar#s su$( as ele$tri$it-+ noise an# vi,ration4

(e responsi,le person :w(o mi*(t ,e t(e manu'a$turer o' t(ema$(ine or t(e appointe# representative in t(e Communit-!must $arr- out t(e appropriate $on'ormit- assessmentpro$e#ures w(i$( involve%

@ t(e preparation o' a te$(ni$al 'ile :$ontainin* in'ormation su$( as'ull #etaile# #rawin*s an# $al$ulations an# a #es$ription o' t(emet(o#s a#opte# to eliminate (a"ar#s presente# ,- t(e

ma$(ine!8@ Ensurin* t(at t(e ma$(ine $omplies wit( t(e re7uirements o'

ot(er relevant EC #ire$tives8

@ ssuin* a #e$laration o' $on'ormit-

@ A''iin* t(e CE mar) to t(e e7uipment in a #istin$t+ visi,le+le*i,le an# in#eli,le manner4


7/50

#tate the main factors to be considered when

devising a s$(eme for the s$stematic

eamination and testing o' portable electrical

appliances. :1=!


8/50

A stu#- o' t(e Ele$tri$it- at /or) >e*ulations 1?? an#a$$ompan-in* ui#an$e Notes :e4*4 HS1=! provi#es t(e'ollowin* strate*- in #evisin* a s$(eme4

An initial inventor- o' t(e e7uipment to ,e eamine# an# teste#+ensurin* t(at ea$( item was provi#e# wit( a uni7ue means o'i#enti'i$ation4

(at $omplete#+ it woul# t(en ,e ne$essar- to #etermine t(eappropriate t-pe an# 're7uen$- o' inspe$tion 'or ea$( item ,ase#on 'a$tors a''e$tin* t(e level o' ris)+ su$( as t(e t-pe o' applian$e+an- prote$tive s-stems provi#e# su$( as eart(in*+ #ou,le

insulation+ or re#u$e# volta*e+ t(e a*e an# usa*e o' t(e applian$e+t(e environment in w(i$( it was use# an# t(e eperien$e an#$ompeten$e o' t(e user4

A##itionall-+ (istori$al #ata+ su$( as previous 'aults or 'ailures o' t(ee7uipment+ an# manu'a$turers re$ommen#ations woul# nee# to

,e ta)en unto $onsi#eration4Criteria 'or ea$( t-pe o' eamination an# test woul# (ave to ,e lai##own w(i$( woul# in$lu#e issues su$( as t(e $ompeten$e o' t(etester+ t(e $ali,ration an# maintenan$e o' test e7uipment+ t(e'ormat o' re$or#s to ,e )ept on t(e results o' t(e tests an#eaminations an# s-stems to i#enti'- an# ta)e out o' use

e7uipment t(at was 'oun# to ,e 'ault-4


9/50

?

a) *dentif$ the sources o' ignition from a t$pical diesel+engined fork+lift truck. :5!

b) Outline the protection that should ,e provided on sucha truck in order to minimise the risk o' eplosion whenit is re!uired to work in a potentiall$ flammableatmosphere. :6!


10/50

1=

a! Sour$es o' i*nition woul# in$lu#e 'lames or spar)s'rom t(e e(aust an# inlet s-stems+ spar)s arisin*'rom t(e tru$)s ele$tri$al s-stem+ stati$ ele$tri$it-,uil#9up ,etween t(e tru$) an# surroun#in*s+ or

t(rou*( over spee#in* or overloa#in* o' t(e en*ine+$ausin* over(eatin* o' t(e ,lo$) or e(aust4


11/50

11

,! An initial prote$tion measure woul# ,e t(e 'ittin* o' 'lame an#spar) arrestors to prevent 'las(,a$) to atmosp(ere i' vapourwas #rawn into t(e inlet s-stem an# to prevent an- 'lames 'romt(e e(aust s-stem es$apin* into t(e air o' t(e wor)pla$e4(e en*ine an# e(aust s-stem s(oul# ,e #esi*ne# to ensuret(at t(eir sur'a$e temperatures were ,elow t(e i*nitiontemperature o' t(e 'lamma,le su,stan$e an# t(e use o' a water

;a$)et on t(e e(aust s-stem woul# provi#e a##itionalprote$tion4Ele$tri$al e7uipment on t(e tru$) s(oul# ,e suita,le 'or "ones 1

an# 2 an# me$(ani$al alternatives :e4*4 a me$(ani$al 'uel*au*e! s(oul# ,e 'itte# w(ere possi,le4(e use o' ele$tri$all- $on#u$tin* ru,,er $omposites 'or partssu$( as t-res an# #rive ,elts woul# re#u$e stati$ ,uil# up w(ile'ittin* spee# an# loa# limiters woul# (elp prevent overspee#in* or over loa#in* o' t(e en*ine4


12/50

12

With the aid of a full$ labelled diagram, identif$ the ke$safet$ features of a building to be used as a facilit$ forthe storage of highl$ flammable solvents in -- litredrums. :1=!


13/50

1

eatures s(oul# in$lu#e%@ Bun#in* to $ontain spills+@ Colle$tin* an# #isposin* o' spilla*es8@ (e ,uil#in* to ,e $onstru$te# o' 'ire resistant materials

@ Li*(t wei*(t roo' an#For ,last panels #ire$te# awa- 'rom ot(er,uil#in*s+

@ Ere$te# on an impermea,le ,ase+@ A#e7uate separation #istan$e 'rom ot(er ,uil#in*s8

@ 0rovision to se*re*ate #i''erent materials or 'ull an# empt-#rums8@ A#e7uate a$$ess an# e*ress in$lu#in* a ramp to 'a$ilitate t(e

(an#lin* o' #rums8@ Hi*(Flow ventilation 'low

@ Sprin)lersF'ire etin*uis(ers to ,e use# in t(e event o' anemer*en$-

@ Se$urit- 'eatures su$( as t(e provision o' lo$)s an# warnin*si*ns4


14/50

15

he owners of a large distribution warehousebusiness have secured a contract 'rom astationer$ manufacturer. heir insurers have

recommended that the proposed storagefacilit$ is sprinkler protected. Outline the designfactors to be considered in providing anade!uate sprinkler s$stem for the facilit$. :1=!


15/50

1<

An initial #esi*n 'a$tor to ,e $onsi#ere# in t(e provision o' ana#e7uate sprin)ler s-stem woul# ,e t(e $apa$it- o' waterre7uire#+ t(e eisten$e o' an a#e7uate an# assure# watersuppl- an# t(e availa,ilit- o' an alternative i' t(is was to

'ail 'or an- reason4 (e #esi*n o' t(e pumpin* s-stemwoul# also ,e important wit( a #iesel ,a$) up i' t(e#e$ision was ta)en to install ele$tri$all- operate# pumps4Ot(er 'a$tors woul# in$lu#e t(e means o' a$tivatin* t(es-stem :'ran*i,le ,ul,s or #ete$tor a$tivate#!8 'ran*i,le

,ul,s woul# ,e pre'era,le in or#er to limit sto$) #ama*e4(ou*( in t(is $ase water woul# ,e t(e pre'erre#etin*uis(ant+ 'oam $oul# also ,e $onsi#ere#4

Ot(er 'a$tors woul# in$lu#e% t(e lin)a*e o' t(e s-stem toalarms8 t(e spra- pattern re7uire#8 t(e area to ,e $overe#

an# t(e presen$e o' ot(er $om,usti,les apart 'rom t(estationer-8 t(e (ei*(t o' t(e stora*e ra$)s an# t(eir#istan$e 'rom t(e sprin)ler (ea#s8 t(e provision o' 'irestoppin* 'or sprin)ler pipe9wor) passin* t(rou*( 'ire$ompartments8 t(e $olle$tion o' 'ire water run o'' an# t(e

arran*ements to ,e put in pla$e 'or testin* t(e e7uipment4


16/50

16

A rectangular warehouse building (Om &--m ground area &&/m high) was constructed on a structural steel framework,with a flat roof and coated steel walls. 0uring a storm, thewarehouse suffered a catastrophic failure o' one of its longwalls which in turn caused collapse of the roo' and buckling o'the other walls.

:a! 0escribe the possible mechanisms o' structural failure thatinvestigators would need to consider as potential causes of theincident. (&-)

(b) Outline the health and safet$ issues to be considered w(en planning the subse!uent demolition of the damagedwarehouse. (&-)


17/50

1

a! 0ossi,le me$(anisms o' stru$tural 'ailure in$lu#ea#verse weat(er $on#itions e$ee#in* #esi*ne# win#loa#in*s8 overloa#in* o' t(e stru$ture ,- e$esswei*(t on t(e roo' $ause# ,- snow or rain water8wea)enin* o' t(e steelwor) ,- $orrosion t(rou*( roo'lea)s or t(e ina#e7ua$- o' rain water #raina*e 'romt(e roo'8 alteration to stru$tural mem,ers or in$reasin*t(e loa# on wall ,eams :e4*4 installin* a *antr- $rane

wit(out #ue $onsi#eration 'or t(e in$rease in loa#in*!w(i$( (a# invali#ate# t(e ori*inal #esi*n $al$ulations8su,si#en$e or near,- e$avation or tunnellin*operations $reatin* insta,ilit- an# vi,ration $ause# ,-t(e volume o' passin* tra''i$8 or win# variation w(i$(

woul# result in 'ati*ue4


18/50

1

:,! ssues woul# in$lu#e% t(e $ompeten$e o' t(e#emolition $ontra$tor8 t(e met(o# to ,e use# 'or#emolis(in* t(e partiall- $ollapse# stru$ture toprevent premature $ollapse o' t(e remain#er8

pre$autions to ,e ta)en to prevent 'alls o' people ormaterial8 t(e i#enti'i$ation an# isolation o' ,urie#servi$es su$( as ele$tri$it- water an# *as8 t(e ris) o'$onta$t wit( over(ea# $a,les ,- #emolition plant8 t(einspe$tion+ eamination an# maintenan$e o' plant an#e7uipment to ,e use#8 pro$e#ures 'or t(e removal o'waste8 t(e prote$tion o' a#;oinin* propert-8 t(ee$lusion o' pe#estrians an# t(e pu,li$ 'rom #an*erareas an# t(e provision o' appropriate personal

prote$tive e7uipment 'or t(e emplo-ees su$( as (ar#(ats+ ,oots an# e-e prote$tion4


19/50

1?

(a) 0escribe the factors that ma$ cause instabilit$ of amobile crane. (/)

(b) Outline the measures that should be taken toreduce the likelihood o' overturning during a liftingoperation. :12!


20/50

2=

:a! a$tors a''e$tin* $rane sta,ilit- woul# in$lu#e%in$orre$t initial sele$tion o' t(e $rane8 in$orre$tslin*in*8 unsta,le *roun# t(at is in$apa,le o' ,earin*t(e wei*(t o' t(e $rane an# its loa#8 slopin* or uneven*roun#8 o,stru$tions ,ein* stru$) ,- t(e $rane or$ausin* t(e loa# to sna*8 e$ee#in* t(e sa'e wor)in*loa#8 in$orre$t operation o' t(e $rane :'or eample int(e non use o' outri**ers!8 in$orre$t t-re pressures8

me$(ani$al 'ailure an# a#verse weat(er $on#itions4

:,! C t l l# i l # i t


21/50

21

:,! Controls woul# in$lu#e% $arr-in* out an area surve-in$lu#in* a 'ull assessment o' t(e environment an#t(e loa# to ,e li'te#8 pro$e#ural $ontrols su$( as t(epreparation o' a li'tin* plan+ sele$tion o' t(e

appropriate $rane+ ensurin* t(e re*ular inspe$tion an#maintenan$e o' t(e $rane an# appointin* a $ompetentperson to supervise t(e li't8 en*ineerin* $ontrols su$(as ensurin* t(e outri**ers are 'ull- eten#e# an# t(att(e $apa$itin#i$ator an# alarm s-stem+ t(e motionan# per'orman$e limit #evi$e an# overloa# limit swit$(are in *oo# wor)in* $on#ition8 an# ,e(avioural$ontrols su$( as t(e $ompeten$e an# trainin* o' t(e#river+ slin*er an# ,an)sman4

1 t ti k i t t k l i l h


22/50

22

1onstruction work is to take place in a rural area whereelectrical power for the site is to ,e gained 'rom aneisting &&k2 overhead suppl$ that cuts across thesite on wooden poles. Outline the control measures to

ensure electrical safet$ in relation to3:a! the overhead suppl$4 (/)

(b) the provision and use of electricit$ on the site4 :12!

:a! 0re plannin* o' sa'e wor)in* pro$e#ures is important (e 'irst step in


23/50

2

:a! 0re9plannin* o' sa'e wor)in* pro$e#ures is important4 (e 'irst step inavoi#in* #an*er is to 'in# out w(et(er t(ere is an- over(ea# ele$tri$ linewit(in or imme#iatel- a#;oinin* t(e wor) area+ or a$ross an- route to it4

or wor) at or near over(ea# power lines+ t(e HSE re$ommen#s t(eappli$ation o' a (ierar$(- $onsistin* o' t(e 'ollowin* a$tions%:a! 'in# out i' t(e wor) (as to ,e $arrie# out un#er or near over(ea# lines:$an it ,e avoi#e# alto*et(er! or+ i' t(is $annot ,e #one8:,! #ivert all over(ea# lines $lear o' t(e wor) area or+ i' it is not reasona,le'or t(is to ,e #one8:$! ma)e lines #ea# w(ile t(e wor) is in pro*ress or+ i' t(is $annot ,e #one8:#! wor) aroun# t(e live over(ea# lines usin* t(e pre$autions outline# in t(is*ui#an$e4

n some $ases it ma- ,e ne$essar- to use suita,le $om,inations o' t(esemeasures4

Liaison ,etween t(e persons responsi,le 'or t(e wor) an# t(e owner:s! o' t(elines s(oul# ,e $ontinue# until t(e wor) (as ,een $omplete#4

Control measures

As 'ollows plus sa'e s-stems o' wor)+ supervision+ warnin* si*ns an# trainin*'or plant operators4


24/50

25


25/50

2<


26/50

26

:,! t( t l t i l # l i #


27/50

2

:,! ssues t(at are relevant in$lu#e plannin* an#assessment 'or t(e #evelopment o' t(e ele$tri$it-suppl- ,- a $ompetent person+ $onsi#erin* t(e si"e o'ele$tri$al suppl- an# possi,le *eneration on9site8 t(e

sa'e positionin* o' trans'ormers8 t(e routein*+ mar)in*an# prote$tion o' $a,les8 t(e use o' prote$tivemeasures su$( as multiple eart(in* arran*ements ont(e site+ re#u$e# low volta*e s-stems+ resi#ual $urrent#evi$es+ #ou,le insulate# e7uipment8 arran*ements'or i#enti'-in*+ inspe$tion an# testin* o' t(e 'ie#suppl- an# porta,le e7uipment8 t(e #evelopment o'sa'e s-stems8 an# t(e use o' $ompetent persons 'orinstallation o' an# wor) on t(e ele$tri$al suppl-4

5 i id t d h th d d


28/50

2

5 serious accident occurred when a threadedsteel rod in the braking mechanism of a hoistbroke. 5n investigation revealed that the cause

o' the breakage was fatigue failure.:a! 0escribe the mechanism and characteristics

o' fatigue failure. (")

(b) 6ist 7%EE factors which can contribute tosuch a failure and for each factor describe one

circumstance in which it ma$ occur. (")

(c) 0escribe the measures that could have beentaken to minimise the likelihood o' such a

failure. :!

:a! ati*ue is a 'orm o' 'ailure t(at o$$urs in materials su,;e$te# to


29/50

2?

:a! ati*ue is a 'orm o' 'ailure t(at o$$urs in materials su,;e$te# to'lu$tuatin* stresses 'or eample+ sol#er ;oints un#ertemperature $-$lin*4 Un#er t(ese $ir$umstan$es+ it is possi,le'or 'ailure to o$$ur at a stress level $onsi#era,l- lower t(an t(etensile or -iel# stren*t( 'or a stati$ loa#4

Alt(ou*( 'ailure is slow in $omin*+ $atastrop(i$ 'ati*ue 'ailureso$$ur ver- su##enl-+ an# wit(out warnin*4

ati*ue 'ailure is ,rittle9li)e in nature4 (e pro$ess o$$urs ,- t(einitiation an# propa*ation o' $ra$)s4 Cra$) *rowt( is ,rou*(ta,out ,- t(e appli$ation o' $-$li$al stresses4

(e e''e$t o' 'ati*ue 'ailure will ,e a**ravate# in t(e $ase o'$omponents w(i$( $ontain a $ra$) intro#u$e# #urin*manu'a$ture4

(e appearan$e o' a 'ati*ue 'ra$ture sur'a$e is #istin$tive an#$onsists o' two portions+ a smoot( portion+ o'ten possessin*$on$(oi#al+ or Gmussel s(ell+ mar)in*s s(owin* t(e pro*ress o't(e 'ati*ue $ra$) up to t(e moment o' 'inal rupture+ an# t(e 'inal'ast 'ra$ture "one4


30/50

=

ati*ue ra$ture

:,! ti ' il i # ,

http://fatigue%20failure.ppt/


31/50

1

:,! ati*ue 'ailure is $ause# ,-#esi*n 'aults su$( as s(arp $orners or (oles w(i$( a$t as a 'o$us 'or stressors

irre*ularities+ 'or eample sur'a$e o$$lusions+ w(i$( provi#e points o' wea)nessin t(e material stru$ture

in$orre$t $(oi$e o' materials 'or t(e environment an# wor)in* $on#itions+ sot(at t(e $omponents are operatin* outsi#e t(e materials $apa,ilities8

resi#ual stresses impose# #urin* manu'a$ture or assem,l-+ w(i$( woul# a*aina$t as wea) points sus$epti,le to stresses

Corrosion $(an*in* t(e $(ara$teristi$s o' a material+ *enerall- wea)enin* orem,rittlin* it

n an a$$i#ent at t(e .ar)(am Collier-+ a #es$en#in* $a*e $arr-in* men 'aile#to slow #own as it approa$(e# t(e ,ottom o' t(e mine s(a't an# 1 minerswere )ille# ,- t(e impa$t4 (e a$$i#ent was $ause# ,- 'ra$ture o' t(e ,ra)e9ro#+ w(en a slowl- *rowin* 'ati*ue $ra$) rea$(e# a $riti$al si"e an# t(e,ra)e9ro# parte#4

.etal 'ati*ue $ame stron*l- to t(e noti$e o' air$ra't en*ineers in 1?


32/50

2

:$! n or#er to minimise t(e li)eli(oo# o' 'ati*ue'ailures+ measures woul# in$lu#e% ensurin* t(att(e #esi*n+ manu'a$ture an# installation

involves t(e $orre$t spe$i'i$ation o' materialsan# $omponents to mat$( servi$e $on#itions8$orre$t assem,l- an# 7ualit- assuran$e8 t(e

maintenan$e+ inspe$tion an# eamination :wit(ND! parti$ularl- o' $riti$al $omponents an#t(eir repla$ement at planne# intervals8 an#measures $onne$te# wit( use su$( as avoi#in*

a,use an# remainin* wit(in #esi*ne#operational limits+ t(e provision o' trainin* an#instru$tion 'or t(ose involve# in t(e use an# t(e)eepin* o' servi$e (istor- re$or#s4

he horizontall$ sliding gate at the bottom of a


33/50

he horizontall$ sliding gate at the bottom of aconstruction site hoist used for raising andlowering both persons and materials is

electricall$ interlocked.(a) *llustrate, b$ means of a schematic diagram, asuitable interlocking arrangement and givereasons for the level of protection shown. (&-)

(b) Outline the factors that could prevent effectiveoperation of the interlocking mechanism andthe measures that would be needed to ensurecontinued effectiveness. (&-)


34/50

5

ate Close# ate Open

ate

ate

: ! ( t ' t ( i ill t t # i


35/50

<

:a! (e t-pe o' s-stem $(osen is illustrate# int(e #ia*ram 9 two limit swit$(es in opposite

mo#es lin)e# into t(e $ontrol $ir$uitr- o' t(e

li'tin* me$(anism4 (e sa'et- a#vanta*e

o''ere# ,- t(is s-stem is t(at it $ompensates

'or 'ailure or sti$)in* o' one o' t(e swit$(es4 '

normall- $lose# or open swit$(es were use# ont(eir own+ 'ailure mi*(t result in $ontinue#

operation o' t(e li't w(en t(e *ate was open4

(e swit$(es s(oul# ,e 'ie# in a positionw(ere t(e- $annot ,e #eli,eratel- we#*e#

open ,- wor)ers w(o wis( to s(ort$ut t(e

pre$aution4

:,! On a $onstru$tion site t(e ar#uous


36/50

6

:,! On a $onstru$tion site+ t(e ar#uous

$on#itions+ #irt- environment+ an# eposure to

a#verse weat(er $on#itions must ,e ta)en into

a$$ount4 (e e7uipment will ,e use# ,- avariet- o' emplo-ees some o' w(om ma- not

,e a#e7uatel- traine#4 Some ma- wis( to

#e'eat t(e sa'et- measure4 .easures to ensure$ontinue# e''e$tiveness s(oul# in$lu#e t(e

sele$tion o' ro,ust $omponents+ $ir$uit #esi*n

to minimise t(e ris) o' eart( 'aults+arran*ements 'or re*ular inspe$tion an#

maintenan$e+ prote$tion 'rom t(e environment

an# e''e$tive supervision4

#tate the statutor$ periods within which a


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#tate the statutor$ periods within which athorough eamination of must be carried outfor the following t$pes of work e!uipment3

&. 5ir Pressure Plant with a air receiver of acapacit$ of 8-- bar litres

. 6ocal Ehaust 2entilation (6E2) e!uipment

8. Power Presses as defined in Part *2 of theProvision and 9se of Work E!uipment%egulations &''/ (P9WE%)

. 6ifting E!uipment

1 Un#er t(e 0ressure S-stems Sa'et- >e*ulations


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14 Un#er t(e 0ressure S-stems Sa'et- >e*ulations2===+ t(e t-pe an# 're7uen$- o' eamination are#e'ine# ,- t(e written s$(eme4 -pi$al perio# woul#,e 12 mont(s unless t(e s-stem was ,ein* use# in

a (ostile environment424 (e COSHH >e*ulations re7uire t(at LE3 is

eamine# t(orou*(l- ,- a $ompetent person wit(in15 mont(s o' t(e last test

4 Un#er 0art 3 o' 0U/E>+ power presses wit( 'ie#*uar#s must ,e t(orou*(l- eamine# at 12 mont(l-intervals+ ot(ers :wit( 'or eample interlo$) *uar#s!ever- 6 mont(s4

54 Un#er LOLE>+ t(orou*( eaminations s(oul# ,eever- 6 mont(s 'or li'tin* e7uipment use# 'or li'tin*or lowerin* people8 ever- si mont(s 'or li'tin*a$$essories su$( as slin*s+ (oo)s an# e-e,olts8 an#ever- 12 mont(s 'or all ot(er e7uipment su$( as

$ranes or li't tru$)s4

& 1alculate the stress on a cable of length -


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?

&. 1alculate the stress on a cable of length -

metres and cross+sectional area -.-8 cm(

under a force of 8 M:

. *f under this force the cable stretches b$ & cm,

calculate the strain on the cable.

& 1alculate the stress on a cable of length -


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5=

&. 1alculate the stress on a cable of length -

metres and cross+sectional area -.-8 m(

under a etensive force of 8 M:

#tress ;

5 household electrical circuit is used for a cooker


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51


which is power rated at &- kilowatts. *f the

household suppl$ voltage is >- 2olts, what

should be the current rating of a mini circuitbreaker installed in the circuit to protect it

against over+current?



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52


which is power+rated at &- kilowatts. *f the

household suppl$ voltage is >- 2olts, what

should be the current rating of a mini circuitbreaker installed in the circuit to protect it

against over+current?

Power (Watts) ; 2olts 5mperes

herefore 5mperes ; Watts = 2olts

; &---- = >- ; - amperes

he M1@ should have a rating of, sa$ > 5mps

to allow for initial power surge.

Eplain the phenomenon of impedance to


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5

Eplain the phenomenon of impedance to

alternating current in an electrical circuit.

mpe#an$e in a $ir$uit is t(e Gresistan$e to t(e


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55

mpe#an$e in a $ir$uit is t(e resistan$e to t(e

passa*e o' alternatin* $urrent+ an# is a

$omposite o' t(e resistan$e+ $apa$itan$e an#

in#u$tive properties o' t(e $ir$uit an# its$omponents4

5n organisation which manufactures flammable solvents


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5<

5n organisation which manufactures flammable solventshas to e!uip a new warehouse for its products, andalso multi+store$ office block, with portable fireetinguishers.

(a) #tate the t$pe of etinguishers that should beinstalled in the warehouse 5:0 the offices (8)

(b) #tate the guidelines give in E: 8 &''" for thenumber of etinguishers that should be provided on

each floor of the office block (8)(c) #tate the guidance formula given in E: 8 &''" that

should be used to calculate the rating of etinguisherwhich should be provided to deal with a burning poolof solvent which might result from a t$pical spill inthe warehouse ()

(d) 6ist the factors to be considered in the suitable andeffective siting of portable fire etinguishers in theworkplace. (&-)

(a) #tate the t$pe of etinguishers that should be


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56

(a) #tate the t$pe of etinguishers that should be

installed in the warehouse 5:0 the offices.

Class A porta,le etin*uis(ers woul# ,e a#e7uate

'or t(e o''i$e+ w(ere onl- $om,usti,le materialssu$( as paper+ 'urniture an# 'ittin* are li)el- to

,e present4 /(ere ele$tri$al e7uipment is

use#+ a CO2 etin*uis(er s(oul# ,e provi#e#4

' t(e sta'' are provi#e# wit( $oo)in* 'a$ilities+pow#er t-pe+ Class t-pe or a ire Blan)et

ma- ,e appropriate4

n t(e /are(ouse+ porta,le etin*uis(ers s(oul#,e suita,le 'or Class B 'ires4 oam or pow#er

t-pes woul# ,e pre'era,le4

(b) #tate the guidelines given in E: 8 &''" for the


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5

(b) #tate the guidelines given in E: 8 &''" for the

number of etinguishers that should be

provided on each floor of the office block.

(e Stan#ar# states t(at+ w(ere a Class A 'ire ist(e most li)el-+ a minimum o' 2 etin*uis(ers

s(oul# ,e provi#e# per 'loor+ unless t(e upper

'loor area is I 1== s74m4 AND (as onl- one

o$$upant4 n an- ot(er $ase+ t(e 'ire ratin*re7uire# is $al$ulate# 'rom t(e 'ormula%

loor Area $overe# :s74m4! =4=6


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5

(c) #tate the guidance formula given in E: 8 &''"

that should be used to calculate the rating of

etinguisher that should be provided to deal

with a burning pool of solvent which mightresult from a t$pical spill in the warehouse

(e Stan#ar# re$ommen#s t(at t(e >atin* o' a

Class B porta,le etin*uis(er s(oul# ,e as

'ollows%

>atin* >e7uire# J 1= 3olume o' Spilla*e4

i4e4 'or a litre spill+ a Class B etin*uis(er wit( a

ratin* o' at least G=B woul# ,e re7uire#4Note% n pra$ti$e e4*4 a stan#ar# etin*uis(er

wit( a 5B ratin* woul# ,e availa,le


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5?

Etin*uis(er >atin*s

(d) 6ist the factors to be considered in the suitable and

http://extinguishers%2002.ppt/http://extinguishers.ppt/


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( )effective siting of portable fire etinguishers in theworkplace.

@ On t(e line o' es$ape routes

@ Near to possi,le site o' 'ires@ Near room eits@ n multi9store- ,uil#in*s+ at t(e same lo$ation on

ea$( 'loor4

@ roupe# at ire 0oints w(ere possi,le@ n wall re$esses w(ere possi,le+ i' site in $orri#ors@ So t(at no person nee# travel more t(an =

metres to rea$( an etin*uis(er

@ /it( t(e $arr-in* (an#le a,out one metre 'rom'loor level

@ Awa- 'rom e$esses o' (eat or $ol#4@ 0rote$te# 'rom #ust an# ot(er $ontaminants

Documents

Diploma Unit C Q&A