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Student ManualWorkplaceSafety and Health

Ordering InformationTo receive documents or other information about occupational safety andhealth topics, contact the National Institute for Occupational Safety and

Health (NIOSH) at

NIOSH—Publications issemination

!"#" $olumbia Par%&ay

$incinnati, OH !'"*++

Telephone- *../'NIOSH (*../'"!"#!)

0a1 number- '*/'//'#/

23mail- pubstaft4cdc56ov

or visit the NIOSH 7eb site at &&&5cdc56ov8niosh

This document is in the public domain and may

be freely copied or reprinted5isclaimer- 9ention of any company or product

does not constitute endorsement by NIOSH5

DHHS (NIOSH) Publication No !""!#$!%

Student ManualJanuary 2002ii

&ckno'ledgmentThis document &as prepared by Thaddeus 75 0o&ler, 2d55, and :aren :5

9iles, Ph55, 2ducation and Information ivision (2I) of the National

Institute for Occupational Safety and Health (NIOSH)5 2ditorial services &ere provided by ;ohn 75 iether5 Pauline 2lliott provided layout and desi6n5

The authors &ish to than% ;ohn Palassis and iana 0laherty (NIOSH), <obert

Nester (formerly of NIOSH), and participatin6 teachers and students for their

contributions to the development of this document5

ore'ordThe National Institute for Occupational Safety and Health (NIOSH) estimates

that ..,... youn6 &or%ers under the a6e of * suffer &or%3related in=uries in

the >nited States each year5 ?oun6 and ne& &or%ers have a hi6h ris% for &or%related

in=ury compared &ith more e1perienced &or%ers5 Occupational safety

and health trainin6 remains a fundamental element of ha@ard control in the &or%place,

and there is 6reat potential to reduce these incidents throu6h pre3employmenttrainin65 2ffective pre3employment trainin6 should include realistic environments

and hands3on e1ercises5 Ho&ever, NIOSH recommends that actual

employment in the electrical trades or any of the other construction trades be

delayed until individuals reach the minimum a6e of *5

This student manual is part of a safety and health curriculum for secondary and

post3secondary electrical trades courses5 The manual is desi6ned to en6a6e the

learner in reco6ni@in6, evaluatin6, and controllin6 ha@ards associated &ith electrical



&or%5 It &as developed throu6h e1tensive research &ith vocational instructors,

and &e are 6rateful for their valuable contributions5

:athleen 95 <est, Ph55, 95P5A5

Actin6 irector

National Institute for Occupational Safety and Healthiii

*ontentPageSection 1 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 *

Electricity Is Dangerous 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 *

Ho& Is an 2lectrical Shoc% <eceivedB 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Summary of Section * 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 '

Section 2 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 "

Dangers of Electrical Shock 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 "

Summary of Section 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 **

Section 3 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 *

Burns Caused by Electricity 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 *

2lectrical 0ires 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 *!

Summary of Section / 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 *'

0irst Aid 0act Sheet 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 *"

Section 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 *

Overvie of the Safety !odel . . . . . . . . . . . . . . . . . . . . . . . . . . *

7hat 9ust Ce one to Ce SafeB 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 *

Summary of Section ! 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 *

Section " 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Safety !odel Stage 1#$ecogni%ing &a%ards 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

Ho& o ?ou <eco6ni@e Ha@ardsB 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

InadeDuate &irin6 ha@ards 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 !

21posed electrical parts ha@ards 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 !

Overhead po&erline ha@ards 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 'efective insulation ha@ards 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 "

Improper 6roundin6 ha@ards 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 #

Overload ha@ards 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

7et conditions ha@ards 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 +Additional ha@ards 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 /.

Summary of Section ' 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 //

Section ' 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 /!

Safety !odel Stage 2#Evaluating &a%ards 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 /!

Ho& o ?ou 2valuate ?our <is%B 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 /!

Summary of Section " 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 /'++i

PageSection ( 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 /"

Safety !odel Stage 3#Controlling &a%ards)

Safe *ork Environ+ent 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 /"

Ho& o ?ou $ontrol Ha@ardsB 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 /"

Ho& o ?ou $reate a Safe 7or% 2nvironmentB 5 5 5 5 5 5 5 5 5 5 5 5 5 5 /"



Eoc% out and ta6 out circuits and eDuipment 5 5 5 5 5 5 5 5 5 5 5 5 5 5 /#

Eoc%3out8ta63out chec%list 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 /

$ontrol inadeDuate &irin6 ha@ards 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 /+

$ontrol ha@ards of fi1ed &irin6 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 !.

$ontrol ha@ards of fle1ible &irin6 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 !.>se fle1ible &irin6 properly 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 !.

>se the ri6ht e1tension cord 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 !$ontrol ha@ards of e1posed live electrical parts- isolate

ener6i@ed components 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 !/

$ontrol ha@ards of e1posure to live electrical &ires-

use proper insulation 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 !!

$ontrol ha@ards of shoc%in6 currents 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 !"

Fround circuits and eDuipment 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 !"

>se F0$IGs 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 !

Cond components to assure 6roundin6 path 5 5 5 5 5 5 5 5 5 5 5 5 !+

$ontrol overload current ha@ards 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 '.

Summary of Section # 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 '

Section , 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 '!

Safety !odel Stage 3#Controlling &a%ards)Safe *ork -ractices 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 '!

Ho& o ?ou 7or% SafelyB 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 '!

Plan your &or% and plan for safety 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 ''

Eadder safety fact sheet 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 'Avoid &et &or%in6 conditions and other dan6ers 5 5 5 5 5 5 5 5 5 5 5 "*

Avoid overhead po&erlines 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 "*

>se proper &irin6 and connectors 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 "*

>se and maintain tools properly 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 "!

7ear correct PP2 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 ""

PP2 fact sheet 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 "

Summary of Section 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 #*

Flossary of Terms 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 #2ndnotes 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 #!

Appendi1 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 #'

Inde1 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 #"

Photo and Fraphics $redits 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 ##

Contents (continued)

Section $,lectricity I Dangerou7henever you &or% &ith po&er tools or on electrical circuits there

is a ris% of electrical ha@ards, especially electrical shoc%5 Anyone

can be e1posed to these ha@ards at home or at &or%5 7or%ers are

e1posed to more ha@ards because =ob sites can be cluttered &ithtools and materials, fast3paced, and open to the &eather5 <is% is alsohi6her at &or% because many =obs involve electric po&er tools5

2lectrical trades &or%ers must pay special attention to electrical ha@ards

because they &or% on electrical circuits5 $omin6 in contact &ith

an electrical volta6e can cause current to flo& throu6h the body,

resultin6 in electrical shoc% and burns5 Serious in=ury or even death

may occur5 As a source of ener6y, electricity is used &ithout much



thou6ht about the ha@ards it can cause5 Cecause electricity is a familiar

part of our lives, it often is not treated &ith enou6h caution5 As a

result, an avera6e of one &or%er is electrocuted on the =ob every day

of every year Electrocution is the third leading cause of orkrelated

deaths a+ong 1'. and 1(.year.olds/ after +otor vehicle

deaths and ork0lace ho+icide Electrocution is the cause of

12 of all ork0lace deaths a+ong young orkers*z ,lectrical hock caue in-ury or death.

Section $ Page $

,lectrical Safety,lectrical 'ork can be deadly if not done afelyNote to the learner /0hi manualdecribe the ha1ard of electrical 'orkand baic approache to 'orking afely

2ou 'ill learn kill to help you recogni1e3e+aluate3 and control electrical ha1ard

0hi information 'ill prepare you for additionalafety training uch a hand#one4ercie and more detailed re+ie' of regulation for electrical 'ork

2our employer3 co#'orker3 and community'ill depend on your e4pertie Start your career off right by learning afe practiceand de+eloping good afety habit Safetyi a +ery important part of any -ob Do itright from the tart

This manual &ill present many topics5 There are four main types of

electrical in=uries- electrocution death due to electrical shock/

electrical shock/ burns/ and falls5 The dan6ers of electricity, electrical

shoc%, and the resultin6 in=uries &ill be discussed5 The various

electrical ha@ards &ill be described5 5ou ill learn about the Safety!odel/ an i+0ortant tool for recogni%ing/ evaluating/ and controlling

ha%ards5 Important definitions and notes are sho&n in the

mar6ins5 Practices that &ill help %eep you safe and free of in=ury are

emphasi@ed5 To 6ive you an idea of the ha@ards caused by electricity,

case studies about real3life deaths &ill be described5

Ho' I an ,lectrical Shock 5ecei+ed6An electrical shoc% is received &hen electrical current passesthrou6h the body5 $urrent &ill pass throu6h the body in a variety of

situations5 7henever t&o &ires are at different volta6es, current &ill

pass bet&een them if they are connected5 ?our body can connect the

&ires if you touch both of them at the same time5 $urrent &ill pass

throu6h your body5

In most household &irin6, the blac% &ires and the red &ires are at

*. volts5 The &hite &ires are at . volts because they are connected

to 6round5 The connection to 6round is often throu6h a conductin6

6round rod driven into the earth5 The connection can also be made

throu6h a buried metal &ater pipe5 If you co+e in contact ith anz current/the movement of electrical chargez +oltage/a measure of



electrical forcez circuit/a complete path for the flowof currentz 2ou 'ill recei+e a hock if youtouch t'o 'ire at different+oltage at the ame timez ground/a physical electrical connection

to the earthz energi1ed (li+e3 7hot8)/similar terms meaning that a voltage ispresent that can cause a current, sothere is a possibility of gettingshocked

Page ! Section $

,9,*05I*I02Wire carry currentenergi%ed black ire#and you are also in contact ith the neutral

hite ire#current ill 0ass through your body 5ou ill

receive an electrical shock 5

If you are in contact ith a live ire or any live co+0onent of an

energi%ed electrical device#and also in contact ith anygrounded ob6ect#you ill receive a shock 5 Plumbin6 is often

6rounded5 9etal electrical bo1es and conduit are 6rounded5

?our ris% of receivin6 a shoc% is 6reater if you stand in a puddle of

&ater5 Cut you donGt even have to be standin6 in &ater to be at ris%5

7et clothin6, hi6h humidity, and perspiration also increase your

chances of bein6 electrocuted5 Of course, there is al&ays a chance of

electrocution, even in dry conditions5z conductor/material in which anelectrical current moves easilyz neutralat ground potential (0 volts)

because of a connection to groundz 2ou 'ill recei+e a hock if

you touch a li+e 'ire and aregrounded at the ame timez When a circuit3 electricalcomponent3 or e:uipment ienergi1ed3 a potential hockha1ard i preent

Section $ Page %I S D&N;,5O<S=lack and red 'ire are uuallyenergi1ed3 and 'hite 'ire areuually neutralMetal electrical bo4e hould be groundedto pre+ent hock

Page > Section $?ou can even receive a shoc% &hen you are not in contact &ith an

electrical 6round5 $ontact &ith both live &ires of a !.3volt cable

&ill deliver a shoc%5 (This type of shoc% can occur because one live

&ire may be at *. volts &hile the other is at 3*. volts durin6 an

alternatin6 current cycle—a difference of !. volts5)5 ?ou can also

receive a shoc% from electrical components that are not 6rounded

properly5 2ven contact &ith another person &ho is receivin6 an electrical

shoc% may cause you to be shoc%ed5



&!0"year"old male electrical technician was helping a company service representative test the voltage"

regulating unit on a new rolling mill. #hile the electrical technician went to get the e$uipmentservice manual, the service representative opened the panel cover of the voltage regulator%s controlcabinet in preparation to trace the low"voltage wiring in $uestion (the wiring was not color"coded). &he

service representative climbed onto a nearby cabinet in order to view the wires. &he technician returnedand began working inside the control cabinet, near e'posed energied electrical conductors. &he techniciantugged at the low"voltage wires while the service representative tried to identify them from above.uddenly, the representative heard the victim making a gurgling sound and looked down to see the victimshaking as though he were being shocked. Cardiopulmonary resuscitation (C*+) was administered to thevictim about 0 minutes later. -e was pronounced dead almost 2 hours later as a result of his contact withan energied electrical conductor.&o prevent an incident like this, employers should take the following steps? /stablish proper rules and procedures on how to access electrical control cabinets without gettinghurt.? ake sure all employees know the importance of de"energiing (shutting off) electrical systems beforeperforming repairs.? /$uip voltage"regulating e$uipment with color"coded wiring.? &rain workers in C*+.

&maintenance man rode 2 feet above the floor on a motoried lift to work on a 211"volt light fi'ture.

-e did not turn off the power supply to the lights. -e removed the line fuse from the black wire,which he thought was the hot3 wire. 4ut, because of a mistake in installation, it turned out that thewhite wire was the hot3 wire, not the black one. &he black wire was neutral. -e began to strip the whitewire using a wire stripper in his right hand. /lectricity passed from the hot3 white wire to the stripper, theninto his hand and through his body, and then to ground through his left inde' finger. 5 co"worker heard anoise and saw the victim lying face"up on the lift. he immediately summoned another worker, who loweredthe platform. C*+ was performed, but the maintenance man could not be saved. -e was pronounceddead at the scene.6ou can prevent in7uries and deaths by remembering the following points? 8f you work on an electrical circuit, test to make sure that the circuit is de"energied (shut off)9? :ever attempt to handle any wires or conductors until you are absolutely positive that their electrical

supply has been shut off.? 4e sure to lock out and tag out circuits so they cannot be re"energied.? 5lways assume a conductor is dangerous.

,9,*05I*I02

Summary of Section $?ou &ill receive an electrical shoc% if a part of your body completes

an electrical circuit by J J J

touchin6 a live &ire and an electrical 6round, or

touchin6 a live &ire and another &ire at a different volta6e5

Section $ Page @&l'ay tet a circuit to makeure it i de#energi1ed before

'orking on itI S D&N;,5O<S

Section !Danger of ,lectrical ShockThe severity of in=ury from electrical shoc% depends on the amount

of electrical current and the len6th of time the current passes

throu6h the body5 0or e1ample, *8*. of an ampere (amp) of electricity



6oin6 throu6h the body for =ust seconds is enou6h to cause

death5 The amount of internal current a person can &ithstand and

still be able to control the muscles of the arm and hand can be less

than *. milliamperes (milliamps or mA)5 $urrents above *. mA

can paraly@e or Kfree@eL muscles5 7hen this Kfree@in6L happens, a person is no lon6er able to release a tool, &ire, or other ob=ect5 In

fact, the electrified ob=ect may be held even more ti6htly, resultin6in lon6er e1posure to the shoc%in6 current5 0or this reason, handheld

tools that 6ive a shoc% can be very dan6erous5 If you canGt let

6o of the tool, current continues throu6h your body for a lon6er

time, &hich can lead to respiratory paralysis (the muscles that control

breathin6 cannot move)5 ?ou stop breathin6 for a period of

time5 People have stopped breathin6 &hen shoc%ed &ith currents

from volta6es as lo& as !+ volts5 >sually, it ta%es about /. mA of

current to cause respiratory paralysis5

$urrents 6reater than #' mA cause ventricular fibrillation (very

rapid, ineffective heartbeat)5 This condition &ill cause death &ithin a

fe& minutes unless a special device called a defibrillator is used to

save the victim5 Heart paralysis occurs at ! amps, &hich means theheart does not pump at all5 Tissue is burned &ith currents 6reater

than ' amps5The table sho&s &hat usually happens for a ran6e of currents

(lastin6 one second) at typical household volta6es5 Eon6er e1posuretimes increase the dan6er to the shoc% victim5 0or e1ample, a current

of *.. mA applied for / seconds is as dan6erous as a current of

+.. mA applied for a fraction of a second (.5./ seconds)5 The muscle

structure of the person also ma%es a difference5 People &ith less

muscle tissue are typically affected at lo&er current levels5 2ven lo&

volta6es can be e1tremely dan6erous because the de6ree of in=ury

depends not only on the amount of current but also on the len6th of

time the body is in contact &ith the circuit57O* 8O79:;E DOES <O9 !E:< 7O* &:=:$D>z ampere (amp)/the unit used to

measure currentz milliampere (milliamp or m&)/;,000 of an amperez hocking current/electrical currentthat passes through a part of thebodyz 2ou 'ill be hurt more if you canAtlet go of a tool gi+ing a hockz 0he longer the hock3 the greater the in-ury

Page B Section !

D&N;,5S O ,9,Defibrillator in ueSometimes hi6h volta6es lead to additional in=uries5 Hi6h volta6es

can cause violent muscular contractions5 ?ou may lose your balance

and fall, &hich can cause in=ury or even death if you fall intomachinery that can crush you5 Hi6h volta6es can also cause severe

burns (as seen on pa6es + and *.)5

At ".. volts, the current throu6h the body may be as 6reat as

! amps, causin6 dama6e to internal or6ans such as the heart5 Hi6h



volta6es also produce burns5 In addition, internal blood vessels may

clot5 Nerves in the area of the contact point may be dama6ed5

9uscle contractions may cause bone fractures from either the contractions

themselves or from falls5

A severe shoc% can cause much more dama6e to the body than isvisible5 A person may suffer internal bleedin6 and destruction of tissues,

nerves, and muscles5 Sometimes the hidden in=uries caused byelectrical shoc% result in a delayed death5 Shoc% is often only the

be6innin6 of a chain of events5 2ven if the electrical current is too

small to cause in=ury, your reaction to the shoc% may cause you to

fall, resultin6 in bruises, bro%en bones, or even death5

The len6th of time of the shoc% 6reatly affects the amount of in=ury5

If the shoc% is short in duration, it may only be painful5 A lon6er z High +oltage caue additionalin-urie.z Higher +oltage can caue larger current and more e+ere hockz Some in-urie from electricalhock cannot be een

Section ! Page C*05I*&9 SHO*,ffect of ,lectrical *urrentE on the =ody!

*urrent 5eaction$ milliamp Just a faint tingle.@ milliamp light shock felt. <isturbing, but not painful. ost people can let go.3-owever, strong involuntary movements can cause in7uries.BF!@ milliamp (women)= *ainful shock. uscular control is lost. &his is the range where freeingGF%" milliamp (men) currents3 start. 8t may not be possible to let go.3@"F$@" milliamp /'tremely painful shock, respiratory arrest (breathing stops), severe musclecontractions. >le'or muscles may cause holding on? e'tensor muscles maycause intense pushing away. <eath is possible.$3"""F>3%"" milliamp @entricular fibrillation (heart pumping action not rhythmic) occurs. uscles(AB.! amps) contract? nerve damage occurs. <eath is likely.

$"3""" milliamp Cardiac arrest and severe burns occur. <eath is probable.(0 amps)$@3""" milliamp owest overcurrent at which a typical fuse or circuit breaker opens a circuit9(D amps)E/ffects are for voltages less than about F00 volts. -igher voltages also cause severe burns.=<ifferences in muscle and fat content affect the severity of shock.

shoc% (lastin6 a fe& seconds) could be fatal if the level of current is

hi6h enou6h to cause the heart to 6o into ventricular fibrillation5This is not much current &hen you reali@e that a small po&er drill

uses /. times as much current as &hat &ill %ill5 At relatively hi6h

currents, death is certain if the shoc% is lon6 enou6h5 Ho&ever, if

the shoc% is short and the heart has not been dama6ed, a normalheartbeat may resume if contact &ith the electrical current is eliminated5

(This type of recovery is rare5)The amount of current

passin6 throu6h the body

also affects the severity of

an electrical shoc%5 Freater

volta6es produce 6reater

currents5 So, there is

6reater dan6er from hi6her

volta6es5 <esistance hinders



current5 The lo&er the

resistance (or impedance in

A$ circuits), the 6reater the

current &ill be5 ry s%in

may have a resistance of *..,... ohms or more5 7et

s%in may have a resistanceof only *,... ohms5 7et

&or%in6 conditions or bro%en

s%in &ill drastically

reduce resistance5 The lo&

resistance of &et s%in

allo&s current to pass into

the body more easily and

6ive a 6reater shoc%5 7hen more force is applied to the contact point

or &hen the contact area is lar6er, the resistance is lo&er, causin6

stron6er shoc%s5

The path of the electrical current throu6h the body affects the severity

of the shoc%5 $urrents throu6h the heart or nervous system aremost dan6erous5 If you contact a live &ire &ith your head, your nervous

system &ill be dama6ed5 $ontactin6 a live electrical part &ith

one hand—&hile you are 6rounded at the other side of your body—

&ill cause electrical current to pass across your chest, possibly in=urin6your heart and lun6s5z 0he greater the current3 thegreater the hock.z Se+erity of hock depend on+oltage3 amperage3 and reitancez reitance/a materialGs ability to

decrease or stop electrical currentz ohm/unit of measurement for

electrical resistancez 9o'er reitance caue greater currentz *urrent acro the chet are +erydangerou

Page Section !

D&N;,5S O ,9Po'er drill ue %" time amuch current a 'hat 'ill killz N,*/National ,lectrical *odea comprehensive listing of practices to protect workers ande$uipment from electrical haardssuch as fire and electrocution

Section ! Page G,*05I*&9 SHO*

&male service technician arrived at a customer%s house to perform pre"winter maintenance on an oil

furnace. &he customer then left the house and returned H0 minutes later. he noticed the servicetruck was still in the driveway. 5fter 2 more hours, the customer entered the crawl space with aflashlight to look for the technician but could not see him. he then called the owner of the company, whocame to the house. -e searched the crawl space and found the technician on his stomach, leaning on his



elbows in front of the furnace. &he assistant county coroner was called and pronounced the techniciandead at the scene. &he victim had electrical burns on his scalp and right elbow.

5fter the incident, an electrician inspected the site. 5 toggle switch that supposedly controlled electricalpower to the furnace was in the off3 position. &he electrician described the wiring as haphaard andconfusing.3&wo weeks later, the county electrical inspector performed another inspection. -e discovered that incorrectwiring of the toggle switch allowed power to flow to the furnace even when the switch was in the off3

position. &he owner of the company stated that the victim was a very thorough worker. *erhaps the victimperformed more maintenance on the furnace than previous technicians, e'posing himself to the electricalhaard.&his death could have been prevented9I &he victim should have tested the circuit to make sure it was de"energied.I /mployers should provide workers with appropriate e$uipment and training. sing safety e$uipmentshould be a re$uirement of the 7ob. 8n this case, a simple circuit tester may have saved the victim%s life.I +esidential wiring should satisfy the :ational /lectrical Code (:/C). 5lthough the :/C is not retroactive,all homeowners should make sure their systems are safe.

,lectrical burn on hand and arm

D&N;,5S O ,9There have been cases &here an arm or le6 is severely burned by

hi6h3volta6e electrical current to the point of comin6 off, and the

victim is not electrocuted5 In these cases, the current passes throu6h

only a part of the limb before it 6oes out of the body and into another conductor5 Therefore, the current does not 6o throu6h the chest area

and may not cause death, even thou6h the victim is severely disfi6ured5

If the current does 6o throu6h the chest, the person &ill almost

surely be electrocuted5 A lar6e number of serious electrical in=uries

involve current passin6 from the hands to the feet5 Such a path

involves both the heart and lun6s5 This type of shoc% is often fatal5

Page $" Section !&rm 'ith third degree burn fromhigh#+oltage line

Summary of Section !The dan6er from electrical shoc% depends on J J Jthe amount of the shoc%in6 current throu6h the body,

the duration of the shoc%in6 current throu6h the body, and

the path of the shoc%in6 current throu6h the body5

,*05I*&9 SHO*Section ! Page $$

Section %=urn *aued by ,lectricityThe most common shoc%3related, nonfatal in=ury is a burn5 Curns

caused by electricity may be of three types- electrical burns/ arc

burns/ and ther+al contact burns5 2lectrical burns can result &hen

a person touches electrical &irin6 or eDuipment that is used or maintainedimproperly5 Typically, such

burns occur on the hands5

2lectrical burns are one of the

most serious in=uries you can

receive5 They need to be 6iven

immediate attention5 Additionally,

clothin6 may catch fire and a

thermal burn may result from the



heat of the fire5

Arc3blasts occur &hen po&erful,

hi6h3ampera6e currents arc

throu6h the air5 Arcin6 is the

luminous electrical dischar6e that occurs &hen hi6h volta6es e1istacross a 6ap bet&een conductors and current travels throu6h the air5

This situation is often caused by eDuipment failure due to abuse or fati6ue5 Temperatures as hi6h as /',...M0 have been reached

in arc3blasts5

There are three primary ha@ards associated &ith an arc3blast5

(*) Arcin6 6ives off thermal radiation (heat) and intense li6ht, &hich

can cause burns5 Several factors affect the de6ree of in=ury, includin6

s%in color, area of s%in e1posed, and type of clothin6 &orn5

Proper clothin6, &or% distances, and overcurrent protection can

reduce the ris% of such a burn5

() A hi6h3volta6e arc can produce a considerable pressure &ave

blast5 A person feet a&ay from a ',...3amp arc feels a force of

about !. pounds on the front of the body5 In addition, such an

e1plosion can cause serious ear dama6e and memory loss due toconcussion5 Sometimes the pressure &ave thro&s the victim a&ay

from the arc3blast5 7hile this may reduce further e1posure to thez ,lectrical hock caue burnz arc#blat/e'plosive release of moltenmaterial from e$uipment caused byhigh"amperage arcsz arcingthe luminous electrical discharge

(bright, electrical sparking)through the air that occurs when highvoltages e'ist across a gap betweenconductors

Page $! Section %

=<5NS *&<S,D*ontact electrical burn 0heknee on the left 'a energi1ed3and the knee on the right 'agroundedthermal ener6y, serious physical in=ury may result5 The pressure

&ave can propel lar6e ob=ects over 6reat distances5 In some cases,

the pressure &ave has enou6h force to snap off the heads of steel bolts and %noc% over &alls5

(/) A hi6h3volta6e arc can also cause many of the copper and aluminum

components in electrical eDuipment to melt5 These droplets

of molten metal can be blasted 6reat distances by the pressure &ave5

Althou6h these droplets harden rapidly, they can still be hot enou6h

to cause serious burns or cause ordinary clothin6 to catch fire, even

if you are *. feet or more a&ay5

Section % Page $%

=2 ,9,*05I*I02

ive technicians were performing preventive maintenance on the electrical system of a railroad maintenance

facility. Kne of the technicians was assigned to clean the lower compartment of an electrical



cabinet using cleaning fluid in an aerosol can. 4ut, he began to clean the upper compartment aswell. &he upper compartment was filled with live circuitry. #hen the cleaningspray contacted the live circuitry, a conductive path for the currentwas created. &he current passed through the stream of fluid, into thetechnician%s arm, and across his chest. &he current caused a loude'plosion. Co"workers found the victim with his clothes on fire. Kneworker put out the fire with an e'tinguisher, and another pulled the victim

away from the compartment with a plastic vacuum cleaner hose.&he paramedics responded in D minutes. 5lthough the victim survivedthe shock, he died 2B hours later of burns.&his death could have been prevented if the following precautionshad been taken? 4efore doing any electrical work, de"energie all circuits ande$uipment, perform lock"out;tag"out, and test circuits ande$uipment to make sure they are de"energied.? &he company should have trained the workers to performtheir 7obs safely.? *roper personal protective e$uipment (**/) should alwaysbe used.? :ever use aerosol spray cans around high"voltage e$uipment.

$> Section %

,lectrical ireElectricity is one of the +ost co++on

causes of fires and ther+al burns in

ho+es and ork0laces efective or

misused electrical eDuipment is ama=or cause of electrical fires5 If

there is a small electrical fire, be

sure to use only a $lass $ or multipurpose

(AC$) fire e1tin6uisher, or you mi6ht ma%e the problem &orse5

All fire e1tin6uishers are mar%ed &ith

letter(s) that tell you the %inds of fires they

can put out5 Some e1tin6uishers containsymbols, too5

The letters and symbols are e1plained belo& (includin6 su66estions on ho& to remember them)5

&(thin%- :shes) paper, &ood, etc5

=(thin%- Barrel) flammable liDuids

*(thin%- Circuits) electrical fires

Here are a couple of fire

e1tin6uishers at a &or%site5

$an you tell &hat types of

fires they &ill put outB

0hi e4tinguiher can onlybe ued on *la = and*la * fire0hi e4tinguiher can only



be ued on *la & and*la * fire

=<5NS *&<S,D9earn ho' to ue firee4tinguiher at 'ork

Ho'e+er3 do not try to put out fire unle you ha+e recei+ed

proper training If you are not trained3 the bet thing you cando i e+acuate the area and call for helpThermal burns may result if an e1plosion occurs &hen electricity

i6nites an e1plosive mi1ture of material in the air5 This i6nition can

result from the buildup of combustible vapors, 6asses, or dusts5

Occupational Safety and Health Administration (OSHA) standards,

the N2$, and other safety standards 6ive precise safety reDuirements

for the operation of electrical systems and eDuipment in such dan6erous

areas5 I6nition can also be caused by overheated conductors

or eDuipment, or by normal arcin6 at s&itch contacts or in circuit brea%ers5

Summary of Section %Curns are the most common in=ury caused by electricity5 The threetypes of burns are J J J

electrical burns,

arc burns, and

thermal contact burns5z OSH&/Occupational Safety andHealth &dministrationthe >ederalagency in the .. <epartment of abor that establishes and enforcesworkplace safety and healthregulations

=2 ,9,*05I*I02Section % Page $@Page $B

Shut off the electrical current if the victim is still in contact

&ith the ener6i@ed circuit5 7hile you do this, have

someone else call for help5 If you cannot 6et to the

s&itch6ear Duic%ly, pry the victim from the circuit &ith somethin6 that does not

conduct electricity such as dry &ood5 Do not touch the victim yourself if he or

she is still in contact with an electrical circuit! ?ou do not &ant to be a victim,

too

o not leave the victim unless there is absolutely no other option5 ?ou should stay

&ith the victim &hile 2mer6ency 9edical Services (29S) is contacted5 The caller

should come bac% to you after&ards to verify that the call &as made5 If the victim

is

not breathin6, does not have a heartbeat, or is badly in=ured, Duic% response by a



team of emer6ency medical technicians (29TGs) or paramedics 6ives the best

chance

for survival5

What Should I Do If a *o#Worker IShocked or =urned by ,lectricity69earn firt aidirt &id act SheetPage $C

Once you %no& that electrical current is no lon6er flo&in6 throu6h the victim, call

out

to the victim to see if he or she is conscious (a&a%e)5 If the victim is conscious,

tell the victim not to move. It is possible for a shoc% victim to be seriously in=ured but

not reali@e it5 uic%ly e1amine the victim for si6ns of ma=or

bleedin65 If there is a lot of bleedin6, place a cloth (such

as a hand%erchief or bandanna) over the &ound and apply

pressure5 If the &ound is in an arm or le6 and %eeps bleedin6

a lot, 6ently elevate the in=ured area &hile %eepin6

pressure on the &ound5 :eep the victim &arm and tal% to

him or her until help arrives5

If the victim is unconscious, chec% for si6ns of breathin65 7hile you do this, move

the victim as little as possible5 If the victim is not breathin6, someone trained in$P< should be6in artificial breathin6, then chec% to see if the victim has a pulse5

uic% action is essential To be effective, $P< must be performed &ithin !

minutes

of the shoc%5

If you are not trained in $P< or first aid, now is the time to 6et trained— before

you

find yourself in this situation As% your instructor or supervisor ho& you can

become

certified in $P<5 ?ou also need to %no&the location of (*) electricity shut3offs

(K%ill s&itchesL), () first3aid supplies,

and (/) a telephone so you

can find them Duic%ly in an

emer6ency5



and *P5 no'.Section >O+er+ie' of the Safety Model

What Mut =e Done to =e Safe6>se the three3sta6e safety model - reco6ni@e, evaluate, and control

ha@ards5 To be safe, you must thin% about your =ob and plan for

ha@ards5 To avoid in=ury or

death, you must understand

and reco6ni@e ha@ards5 ?ou

need to evaluate the situation

you are in and assess your

ris%s5 ?ou need to control ha@ards

by creatin6 a safe &or%

environment, by usin6 safe

&or% practices, and by reportin6

ha@ards to a supervisor or teacher5

If you do not reco6ni@e, evaluate,

and control ha@ards, you

may be in=ured or %illed by the

electricity itself, electrical

fires, or falls5 If you use the

safety model to reco6ni@e,

evaluate, and control ha@ards,

you are much safer5

($) 5ecogni1e ha1ardThe first part of the safety model is reco6ni@in6 the ha@ards around

you5 Only then can you avoid or control the ha@ards5 It is best todiscuss and plan ha@ard reco6nition tas%s &ith your co3&or%ers5

Sometimes &e ta%e ris%s ourselves, but &hen &e are responsible for

others, &e are more careful5 Sometimes others see ha@ards that &e

overloo%5 Of course, it is possible to be tal%ed out of our concernsz <e the afety model to recogni1e3e+aluate3 and control ha1ardz Identify electrical ha1ardz DonAt liten to reckle3dangerou people

Page $ Section >

OJ,5JI,W O 0H,5eport ha1ard to your uper+ior

or teacher by someone &ho is rec%less or dan6erous5 onGt ta%e a chance5

$areful plannin6 of safety procedures reduces the ris% of in=ury5

ecisions to loc% out and ta6 out circuits and eDuipment need to be

made durin6 this part of the safety model5 Plans for action must be

made no&5

(!) ,+aluate ha1ard7hen evaluatin6 ha@ards, it is best to identify all possible ha@ards



first, then evaluate the ris% of in=ury from each ha@ard5 o not

assume the ris% is lo& until you evaluate the ha@ard5 It is dan6erous

to overloo% ha@ards5 ;ob sites are especially dan6erous because they

are al&ays chan6in65 9any people are &or%in6 at different tas%s5

;ob sites are freDuently e1posed to bad &eather5 A reasonable placeto &or% on a bri6ht, sunny day mi6ht be very ha@ardous in the rain5

The ris%s in your &or% environment need to be evaluated all thetime5 Then, &hatever ha@ards are present need to be controlled5

(%) *ontrol ha1ardOnce electrical ha@ards have been reco6ni@ed and evaluated, they

must be controlled5 ?ou control electrical ha@ards in t&o main &ays-

(*) create a safe &or% environment and () use safe &or% practices5$ontrollin6 electrical ha@ards (as &ell as other ha@ards) reduces the

ris% of in=ury or death5

OSHA re6ulations, the N2$, and the National

2lectrical Safety $ode (N2S$) provide a &ide

ran6e of safety information5 Althou6h these sources

may be difficult to read and understand at first, &ith

practice they can become very useful tools to help

you reco6ni@e unsafe conditions and practices5

:no&led6e of OSHA standards is an important part

of trainin6 for electrical apprentices5 See the

Appendi1 for a list of relevant standards5z ,+aluate your rikz 0ake tep to control ha1ard*reate a afe 'orkplaceWork afely

Section > Page $G

S&,02 MOD,9&l'ay lock out and tag out circuit

Page !" Section >OJ,5JI,W O 0H,<e the afety model to recogni1e3 e+aluate3 and control 'orkplace ha1ard like thoe inthi picture

Summary of Section >The three sta6es of the safety model are J J J

Stage 1 — Recognize ha@ards

Stage 2 — Evaluate ha@ards

Stage 3 — Control ha@ardsSection > Page !$

S&,02 MOD,9

Section @Safety Model Stage $/5ecogni1ing Ha1ardHo' Do 2ou 5ecogni1e Ha1ard6



The first step to&ard protectin6 yourself is reco6ni@in6 the many

ha@ards you face on the =ob5 To do this, you must %no& &hich situations

can place you in dan6er5 :no&in6 &here to loo% helps you to

reco6ni@e ha@ards5

q InadeDuate &irin6 is dan6erous5

q 21posed electrical parts are dan6erous5

q Overhead po&erlines are dan6erous5q 7ires &ith bad insulation can 6ive you a shoc%5

q 2lectrical systems and tools that are not 6rounded or double3insulated

are dan6erous5

q Overloaded circuits are dan6erous5

q ama6ed po&er tools and eDuipment are electrical ha@ards5

q >sin6 the &ron6 PP2 is dan6erous5

q >sin6 the &ron6 tool is dan6erous5

q Some on3site chemicals are harmful5

q efective ladders and scaffoldin6 are dan6erous5

q Eadders that conduct electricity are dan6erous5

q 2lectrical ha@ards can be made &orse if the &or%er, location, or

eDuipment is &et5z Worker face many ha1ard

on the -ob

Page !! Section @

S&,02 MOD,9 S0&;, $Section @ Page !%

/5,*O;NIKIN; H&K&5DSWorker 'a electrocuted 'hile remo+ingenergi1ed fih tapeih tape

&n electrician was removing a metal fish tape from a hole at the base of a metal light pole. (5

fish tape is used to pull wire through a conduit run.) &he fish tape became energied, electrocutinghim. 5s a result of its inspection, K-5 issued a citation for three serious violations of the agency%s construction standards.8f the following K-5 re$uirements had been followed, this death could have beenprevented.I <e"energie all circuits before beginning work.I 5lways lock out and tag out de"energied e$uipment.I Companies must train workers to recognie and avoid unsafe conditions associatedwith their work.

Inade:uate 'iring ha1ardAn electrical ha@ard e1ists &hen the &ire is too small a 6au6e for the

current it &ill carry5 Normally, the circuit brea%er in a circuit is

matched to the &ire si@e5 Ho&ever, in older &irin6, branch lines to permanent ceilin6 li6ht fi1tures could be &ired &ith a smaller 6au6e

than the supply cable5 EetGs say a li6ht fi1ture is replaced &ith another

device that uses more current5 The current capacity (ampacity) of the

branch &ire could be e1ceeded5 7hen a &ire is too small for the current

it is supposed to carry, the &ire &ill heat up5 The heated &ire

could cause a fire5

7hen you use an e1tension cord, the si@e of the &ire you are placin6

into the circuit may be too small for the eDuipment5 The circuit



brea%er could be the ri6ht si@e for the circuit but not ri6ht for the

smaller36au6e e1tension cord5 A tool plu66ed into the e1tension cord

may use more current than the cord can handle &ithout trippin6 the

circuit brea%er5 The &ire &ill overheat and could cause a fire5

The %ind of metal used as a conductor can cause an electricalha@ard5 Special care needs to be ta%en &ith aluminum &ire5

Since it is more brittle than copper, aluminum &ire can crac% and brea% more easily5

$onnections &ith aluminum

&ire can become loose and

o1idi@e if not made properly,

creatin6 heat or arcin65 You

need to recognize that inadequate

wiring is a hazard 5

,4poed electricalpart ha1ard2lectrical ha@ards e1ist &hen

&ires or other electrical partsare e1posed5 7ires and partscan be e1posed if a cover is

removed from a &irin6 or

brea%er bo15 The overhead

&ires comin6 into a home

may be e1posed5 2lectricalz 'ire gauge/wire sie or diameter (technically, the cross"sectional area)z ampacity/the ma'imum amountof current a wire can carry safelywithout overheatingz O+erloaded 'ire get hot.z Incorrect 'iring practice can

caue fire.z If you touch li+e electrical part3you 'ill be hocked

Page !> Section @

S&,02 MOD,9 S0&;, $0hi hand#held ander hae4poed 'ire and hould notbe uedterminals in motors, appliances, and electronic eDuipment may be

e1posed5 Older eDuipment may have e1posed electrical parts5 If youcontact e1posed live electrical parts, you &ill be shoc%ed5 You need

to recognize that an exposed electrical component is a hazard

O+erhead po'erline ha1ard9ost people do not reali@e that overhead po&erlines are usually not

insulated5 9ore than half of all electrocutions are caused by direct

&or%er contact &ith ener6i@ed po&erlines5 Po&erline &or%ers must

be especially a&are of the dan6ers of overhead lines5 In the past,. of all lineman deaths &ere caused by contactin6 a live &ire

&ith a bare hand5 ue to such incidents, all linemen no& &ear special

rubber 6loves that protect them up to /!,'.. volts5 Today, most

electrocutions involvin6 overhead po&erlines are caused by failure



to maintain proper &or% distances5z O+erhead po'erline kill many'orker.

Section @ Page !@

/5,*O;NIKIN; H&K&5DSWatch out for e4poed electrical 'ire around

electronic e:uipment,lectrical line 'orker need pecial trainingand e:uipment to 'ork afelyShoc%s and electrocutions occur &here

physical barriers are not in place to prevent

contact &ith the &ires5 7hen dump truc%s,

cranes, &or% platforms, or other conductive

materials (such as pipes and ladders) contact

overhead &ires, the eDuipment operator or

other &or%ers can be %illed5 If you do not

maintain reDuired clearance distances from po&erlines, you can be shoc%ed and %illed5

(The minimum distance for volta6es up to'.%Q is *. feet5 0or volta6es over '.%Q, the

minimum distance is *. feet plus ! inchesfor every *. %Q over '.%Q5) Never store

materials and eDuipment under or near overhead

po&erlines5 You need to recognize that

overhead powerlines are a hazard 5

Defecti+e inulation ha1ardInsulation that is defective or inadeDuate is an electrical

ha@ard5 >sually, a plastic or rubber coverin6 insulates &ires5

Insulation prevents conductors from comin6 in contact &ith each

other5 Insulation also prevents conductors from comin6 in contact

&ith people5z inulation/material that does notconduct electricity easily

Page !B Section @

S&,02 MOD,9 S0&;, $Operating a crane near o+erhead 'ire i+ery ha1ardou

ive workers were constructing a chain"link fence in front of a

house, directly below a 1,200"volt energied powerline. 5s theyprepared to install 2"foot sections of metal top rail on the

fence, one of the workers picked up a section of rail and held it upvertically. &he rail contacted the 1,200"volt line, and the worker waselectrocuted. >ollowing inspection, K-5 determined that theemployee who was killed had never received any safety trainingfrom his employer and no specific instruction on how to avoid thehaards associated with overhead powerlines.8n this case, the company failed to obey these regulationsI /mployers must train their workers to recognie and avoid unsafeconditions on the 7ob.I /mployers must not allow their workers to work near any part of an electrical circuit <N9,SS the circuit is de"energied (shut off)



and grounded, or guarded in such a way that it cannot be contacted.I Lround"fault protection must be provided at construction sites toguard against electrical shock.

21tension cords may have dama6ed insulation5 Sometimes the insulation

inside an electrical tool or appliance is dama6ed5 7hen insulation

is dama6ed, e1posed metal

parts may become ener6i@ed if a live &ire inside touches them5

2lectric hand tools that are old,dama6ed, or misused may have

dama6ed insulation inside5 If

you touch dama6ed po&er tools

or other eDuipment, you &ill

receive a shoc%5 ?ou are more

li%ely to receive a shoc% if the

tool is not 6rounded or doubleinsulated5

(ouble3insulated

tools have t&o insulation barriers

and no e1posed metal

parts5) You need to recognize

that defective insulation is a

hazard 5

Improper grounding ha1ard7hen an electrical system is not 6rounded properly, a ha@ard e1ists5

The most common OSHA electrical violation is improper 6roundin6

of eDuipment and circuitry5 The metal parts of an electrical &irin6

system that &e touch (s&itch plates, ceilin6 li6ht fi1tures, conduit,

etc5) should be 6rounded and at . volts5 If the system is not 6rounded

properly, these parts may become ener6i@ed5 9etal parts of motors,

appliances, or electronics that are plu66ed into improperly 6rounded

circuits may be ener6i@ed5 7hen a circuit is not 6rounded properly, aha@ard e1ists because un&anted volta6e cannot be safely eliminated5

If there is no safe path to 6round for fault currents, e1posed metal

parts in dama6ed appliances can become ener6i@ed521tension cords may not provide a continuous path to 6round

because of a bro%en 6round &ire or plu65 If you contact a defectivez If you touch a damaged li+e po'er tool3 you 'ill be hocked.z & damaged li+e po'er tool that inot grounded or double#inulatedi +ery dangerou.z fault current/any current that is notin its intended pathz ground potential/the voltage a

grounded part should have?0 volts relative to ground

Section @ Page !C

/5,*O;NIKIN; H&K&5DS0hi e4tenion cord idamaged and houldnot be uedelectrical device that is not 6rounded (or 6rounded improperly), you

&ill be shoc%ed5 You need to recognize that an improperly grounded



electrical system is a hazard .

2lectrical systems are often 6rounded to metal &ater pipes that serve

as a continuous path to 6round5 If plumbin6 is used as a path to 6round

for fault current, all pipes must be made of conductive material (a type

of metal)5 9any electrocutions and fires occur because (durin6 renovationor repair) parts of metal plumbin6 are replaced &ith plastic pipe,

&hich does not conduct electricity5 In these cases, the path to 6roundis interrupted by nonconductive material5

: ground fault circuit interru0ter/ or ;?CI, is an ine1pensive lifesaver5

F0$IGs detect any difference in current bet&een the t&o circuit

&ires (the blac% &ires and &hite &ires)5 This difference

in current could happen &hen electrical

eDuipment is not &or%in6 correctly,

causin6 lea%a6e current5 If lea%a6e

current (a 6round fault) is detected in a

F0$I3protected circuit, the F0$I s&itches

off the current in the circuit, protectin6 you

from a dan6erous shoc%5 F0$IGs are set at about

' mA and are desi6ned to protect &or%ers fromelectrocution5 F0$IGs are able to detect the loss of

current resultin6 from lea%a6e throu6h a person &ho is be6innin6 to

be shoc%ed5 If this situation occurs, the F0$I s&itches off the current

in the circuit5 F0$IGs are different from circuit brea%ers because theydetect lea%a6e currents rather than overloads5

$ircuits &ith missin6, dama6ed, or improperly &ired F0$IGs may

allo& you to be shoc%ed5 You need to recognize that a circuit

improperly protected by a C" is a hazard .

O+erload ha1ardOverloads in an electrical system are

ha@ardous because they can produce heat

or arcin65 7ires and other componentsin an electrical system or circuit have a

ma1imum amount of current they can

carry safely5 If too many devices are

plu66ed into a circuit, the electrical current

&ill heat the &ires to a very hi6h

temperature5 If any one tool uses too

much current, the &ires &ill heat up5z If you touch a defecti+e li+ecomponent that i not grounded3you 'ill be hockedz ;*I/ground f ault circuitinterruptera device that detects

current leakage from a circuit toground and shuts the current off z leakage current/current that doesnot return through the intended pathbut instead Mleaks3 to groundz ground fault/a loss of current from

a circuit to a ground connectionz o+erload/too much currentin a circuitz &n o+erload can lead to a fire or



electrical hock

Page ! Section @

S&,02 MOD,9 S0&;, $;*I receptacleO+erload are a ma-or caueof fire

The temperature of the &ires can be hi6h enou6h to cause a fire5 If their insulation melts, arcin6 may occur5 Arcin6 can cause a fire in

the area &here the overload e1ists, even inside a &all5

In order to prevent too much current in a circuit, a circuit brea%er or

fuse is placed in the circuit5 If there is too much current in the circuit,

the brea%er KtripsL and opens li%e a s&itch5 If an overloaded

circuit is eDuipped &ith a fuse, an internal part of the fuse melts,

openin6 the circuit5 Coth brea%ers and fuses do the same thin6- open

the circuit to shut off the electrical current5

If the brea%ers or fuses are too bi6 for the &ires they are supposed to

protect, an overload in the circuit &ill not be detected and the current

&ill not be shut off5 Overloadin6 leads to overheatin6 of circuit

components (includin6 &ires) and may cause a fire5 You need torecognize that a circuit with improper overcurrent protection

devices#or one with no overcurrent protection devices at all#

is a hazard .

Overcurrent protection devices are built into the &irin6 of someelectric motors, tools, and electronic devices5 0or e1ample, if a tool

dra&s too much current or if it overheats, the current &ill be shut off

from &ithin the device itself5 ama6ed tools can overheat and cause

a fire5 You need to recognize that a damaged tool is a hazard 5

Wet condition ha1ard7or%in6 in &et conditions is ha@ardous because you may become an

easy path for electrical current5 If you touch a live &ire or other

electrical component—and you are &ell36rounded because you arestandin6 in even a small puddle of &ater—you &ill receive a shoc%5z circuit breaker/an overcurrentprotection device that automaticallyshuts off the current in a circuit if anoverload occursz trip/the automatic opening(turning off) of a circuit by a L>C8 or circuit breaker z fue/an overcurrent protectiondevice that has an internal part thatmelts and shuts off the current in acircuit if there is an overloadz *ircuit breaker and fue that

are too big for the circuit aredangerouz *ircuit 'ithout circuit breaker or fue are dangerouz Damaged po'er tool can caueo+erloadz Wet condition are dangerou

Section @ Page !G

/5,*O;NIKIN; H&K&5DSDamaged e:uipment can o+erheat and



caue a fireama6ed insulation, eDuipment, or tools can e1pose you to live

electrical parts5 A dama6ed tool may not be 6rounded properly, so

the housin6 of the tool may be ener6i@ed, causin6 you to receive a

shoc%5 Improperly 6rounded metal s&itch plates and ceilin6 li6htsare especially ha@ardous in &et conditions5 If you touch a live electrical

component &ith an uninsulated hand tool, you are more li%elyto receive a shoc% &hen standin6 in &ater5

Cut remember- you donGt have to be standin6 in &ater to be electrocuted5

7et clothin6, hi6h humidity, and perspiration also increase

your chances of bein6 electrocuted5 You need to recognize that all

wet conditions are hazards5

&dditional ha1ardIn addition to electrical ha@ards, other types of ha@ards are present at

=ob sites5 <emember that all of these ha@ards can be controlled5

q There may be chemical ha@ards5 Solvents and other substances

may be poisonous or cause disease5

q 0reDuent overhead &or% can cause tendinitis (inflammation) in

your shoulders5z &n electrical circuit in a dampplace 'ithout a ;*I i dangerou.& ;*I reduce the dangerz 0here are non#electrical ha1ard at

-ob ite3 too

Page %" Section @

S&,02 MOD,9 S0&;, $O+erhead 'ork can cauelong#term houlder painq Intensive use of hand tools that involve force or t&istin6 can

cause tendinitis of the hands, &rists, or elbo&s5 >se of hand

tools can also cause carpal tunnel syndrome, &hich results &hennerves in the &rist are dama6ed by s&ellin6 tendons or contractin6

muscles5zPP,/personal protectivee$uipment (eye protection,hard hat, special clothing,etc.)

Section @ Page %$

/5,*O;NIKIN; H&K&5DSre:uent ue of ome hand tool can caue 'ritproblem uch a carpal tunnel yndrome

&22"year"old carpenter%s apprentice was killed when he was struck in the head by a nail

fired from a powder"actuated nail gun (a device that uses a gun powder cartridge todrive nails into concrete or steel). &he nail gun operator fired the gun while attemptingto anchor a plywood concrete form, causing the nail to pass through the hollow form. &he nailtraveled 21 feet before striking the victim. &he nail gun operator had never received trainingon how to use the tool, and none of the employees in the area was wearing **/.8n another situation, two workers were building a wall while remodeling a house. Kne of theworkers was killed when he was struck by a nail fired from a powder"actuated nail gun. &hetool operator who fired the nail was trying to attach a piece of plywood to a wooden stud. 4utthe nail shot though the plywood and stud, striking the victim.



4elow are some K-5 regulations that should have been followed.I /mployees using powder" or pressure"actuated tools must be trained to use them safely.I /mployees who operate powder" or pressure"actuated tools must be trained to avoid firinginto easily penetrated materials (like plywood).I 8n areas where workers could be e'posed to flying nails, appropriate **/ must be used.

q Eo& bac% pain can result from liftin6 ob=ects the &ron6 &ay or

carryin6 heavy loads of &ire or other material5 Cac% pain can

also occur as a result of in=ury from poor &or%in6 surfaces suchas &et or slippery floors5 Cac% pain is common, but it can be disablin6

and can affect youn6 individuals5

q $hips and particles flyin6 from tools can in=ure your eyes5 7ear

eye protection5

q 0allin6 ob=ects can hit you5 7ear a hard hat5

q Sharp tools and po&er eDuipment can cause cuts and other

in=uries5 If you receive a shoc%, you may react and be hurt

by a tool5

q ?ou can be in=ured or %illed by fallin6 from a ladder or scaffoldin65

If you receive a shoc%—even a mild one—you may lose

your balance and fall5 2ven &ithout bein6 shoc%ed, you could

fall from a ladder or scaffoldin65q ?ou e1pose yourself to ha@ards &hen you do not &ear PP25

$ll of these situations need to be recognized as hazards%

Page %! Section @

S&,02 MOD,9 S0&;, $9ift 'ith your leg3 notyour back.

2ou need to be epeciallycareful 'hen 'orking oncaffolding or ladder

Summary of Section @?ou need to be able to reco6ni@e that electrical shoc%s, fires, or falls

result from these ha@ards-

InadeDuate &irin6

21posed electrical parts

Overhead po&erlines

efective insulation

Improper 6roundin6Overloaded circuits

7et conditions

ama6ed tools and eDuipment

Improper PP2

Section @ Page %%

/5,*O;NIKIN; H&K&5DSSection BSafety Model Stage !/,+aluating Ha1ardHo' Do 2ou ,+aluate 2our 5ik6After you reco6ni@e a ha@ard, your ne1t step is to evaluate your ris%

from the ha@ard5 Obviously, e1posed &ires should be reco6ni@ed as



a ha@ard5 If the e1posed &ires are *' feet off the 6round, your ris% is

lo&5 Ho&ever, if you are 6oin6 to be &or%in6 on a roof near those

same &ires, your ris% is hi6h5 The ris% of shoc% is 6reater if you &ill

be carryin6 metal conduit that could touch the e1posed &ires5 ?ou

must constantly evaluate your ris%5$ombinations of ha@ards increase your ris%5 Improper 6roundin6

and a dama6ed tool 6reatly increase your ris%5 7et conditions combined&ith other ha@ards also increase your ris%5 ?ou &ill need to

ma%e decisions about the nature of ha@ards in order to evaluate your

ris% and do the ri6ht thin6 to remain safe5

There are KcluesL that electrical ha@ards e1ist5 0or e1ample, if a

F0$I %eeps trippin6 &hile you are usin6 a po&er tool, there is a

problem5 onGt %eep resettin6 the F0$I and continue to &or%5 ?ou

must evaluate the KclueL and decide &hat action should be ta%en to

control the ha@ard5 There are a number of other conditions that indicate

a ha@ard5

q Tripped circuit brea%ers and blo&n fuses sho& that too much

current is flo&in6 in a circuit5 This condition could be due to several

factors, such as malfunctionin6 eDuipment or a short bet&eenconductors5 ?ou need to determine the cause in order to control

the ha@ard5

q An electrical tool, appliance, &ire, or connection that feels &arm

may indicate too much current in the circuit or eDuipment5 ?ou

need to evaluate the situation and determine your ris%5

q An e1tension cord that feels &arm may indicate too much current

for the &ire si@e of the cord5 ?ou must decide &hen action needs

to be ta%en5z rik/the chance that in7ury or

death will occur z Make the right deciionz hort/a low"resistance path

between a live wire and theground, or between wires atdifferent voltages (called a faultif the current is unintended)

Page %> Section B

S&,02 MOD,9 S0&;,*ombination of ha1ard increae rik Any of these conditions, or

“clues ,” tells you something

important: there is a risk of fire

and electrical shock. The equipment

or tools involved must be

avoided. You ill frequently becaught in situations here you

need to decide if these clues are

present. A maintenance electrician,

supervisor, or instructor

needs to be called if there are

signs of overload and you are not

sure of the degree of risk. Ask for help henever you are not sure



hat to do. !y asking for help, you

ill protect yourself and others.

q A cable, fuse bo1, or =unction bo1 that feels &arm may indicate

too much current in the circuits5

q A burnin6 odor may indicate overheated insulation5

q 7orn, frayed, or dama6ed insulation around any &ire or other

conductor is an electrical ha@ard because the conductors could bee1posed5 $ontact &ith an e1posed &ire could cause a shoc%5

ama6ed insulation could cause a short, leadin6 to arcin6 or a

fire5 Inspect all insulation for scrapes and brea%s5 ?ou need to

evaluate the seriousness of any dama6e you find and decide ho&

to deal &ith the ha@ard5

q A F0$I that trips indicates there is current lea%a6e from the circuit5

0irst, you must decide the probable cause of the lea%a6e by

reco6ni@in6 any contributin6 ha@ards5 Then, you must decide

&hat action needs to be ta%en5

Summary of Section BEoo% for KcluesL that ha@ards are present5

2valuate the seriousness of ha@ards5

ecide if you need to ta%e action5

onGt i6nore si6ns of trouble5

Section B Page %@

!/,J&9<&0IN; H&K&5DS

&n N"year"old male worker, with D months of e'perience at a fast food restaurant, was plugging a toaster

into a floor outlet when he received a shock. ince the restaurant was closed for the night, the floor had been mopped about 0 minutes before the incident. &he restaurant manager and another employeeheard the victim scream and investigated. &he victim was found with one hand on the plug and the other handgrasping the metal receptacle bo'. -is face was pressed against the top of the outlet. 5n employee tried to take

the victim%s pulse but was shocked. &he manager could not locate the correct breaker for the circuit. -e thencalled the emergency s$uad, returned to the breaker bo', and found the correct breaker. 4y the time the circuitwas opened (turned off), the victim had been e'posed to the current for ! to N minutes. &he employee checkedthe victim%s pulse again and found that it was very rapid.&he manager and the employee left the victim to unlock the front door and place another call for help. 5nother employee arrived at the restaurant and found that the victim no longer had a pulse. &he employee beganadministering C*+, which was continued by the rescue s$uad for H0 minutes. &he victim was dead on arrivalat a local hospital.ater, two electricians evaluated the circuit and found no serious problems. 5n investigation showed that thevictim%s hand slipped forward when he was plugging in the toaster. -is inde' finger made contact with anenergied prong in the plug. -is other hand was on the metal receptacle bo', which was grounded. Currententered his body through his inde' finger, flowed across his chest, and e'ited through the other hand, whichwas in contact with the grounded receptacle.&o prevent death or in7ury, you must recognie haards and take the right action.I 8f the circuit had been e$uipped with a L>C8, the current would have been shut off before in7ury occurred.I &he recent mopping increased the risk of electrocution. :ever work in wet or damp areas9

Section CSafety Model Stage %/*ontrolling Ha1ardSafe Work ,n+ironmentHo' Do 2ou *ontrol Ha1ard6



In order to control ha@ards, you must first create a safe &or% environment,

then &or% in a safe manner5 Fenerally, it is best to remove

the ha@ards alto6ether and create an environment that is truly safe5

7hen OSHA re6ulations and the N2$ are follo&ed, safe &or% environments

are created5Cut, you never %no& &hen materials or eDuipment mi6ht fail5

Prepare yourself for the une1pected by usin6 safe &or% practices5>se as many safe6uards as possible5 If one fails, another may protect

you from in=ury or death5

Ho' Do 2ou *reate a Safe Work ,n+ironment6A safe &or% environment is created by controllin6 contact &ith electrical

volta6es and the currents they can cause5 2lectrical currentsneed to be controlled so they do not pass throu6h the body5 In addition

to preventin6 shoc%s, a safe &or% environment reduces the

chance of fires, burns, and falls5

?ou need to 6uard a6ainst contact &ith electrical volta6es and control

electrical currents in order to create a safe &or% environment5

9a%e your environment safer by doin6 the follo&in6-

q Treat all conductors—even Kde3ener6i@edL ones—as if they are

ener6i@ed until they are loc%ed out and ta66ed5

q Eoc% out and ta6 out circuits and machines5

q Prevent overloaded &irin6 by usin6 the ri6ht si@e and

type of &ire5

q Prevent e1posure to live electrical parts by isolatin6 them5

q Prevent e1posure to live &ires and parts by usin6 insulation5

q Prevent shoc%in6 currents from electrical systems and tools by

6roundin6 them5

q Prevent shoc%in6 currents by usin6 F0$IGs5

q Prevent too much current in circuits by usin6 overcurrent

protection devices5z ;uard againt contact 'ithelectrical +oltage and controlelectrical current to create aafe 'ork en+ironment

Page %B Section C

S&,02 MOD,9 S0&;, %/*ON05O99IN;

9ock out and tag out circuit and e:uipment$reate a safe &or% environment by loc%in6 out and ta66in6 out

circuits and machines5 Cefore &or%in6 on a circuit, you must

turn off the po&er supply5 Once the circuit has been shut off and

de3ener6i@ed, loc% out the s&itch6ear to the circuit so the po&er

cannot be turned bac% on inadvertently5 Then, ta6 out the circuit

&ith an easy3to3see si6n or label that lets everyone %no& that you are&or%in6 on the circuit5 If you are &or%in6 on or near machinery,

you must loc% out and ta6 out the machinery to prevent startup5Cefore you be6in &or%, you must test the circuit to ma%e sure it is

de3ener6i@ed5

Section C Page %C

H&K&5DS S&, WO5 ,NJI5ONM,N0



&t about BD a.m., two 7ourneyman electricians began replacing bulbs and making repairs on light

fi'tures in a spray paint booth at an automobile assembly plant. &he 7ob re$uired the twoelectricians to climb on top of the booth and work from above. &he top of the booth was filled withpipes and ducts that restricted visibility and movement. >lashlights were re$uired.

&he electricians started at opposite ends of the booth. Kne electrician saw a flash of light, but continuedto work for about D minutes, then climbed down for some wire. #hile cutting the wire, he smelled a burningodor and called to the other electrician. #hen no one answered, he climbed back on top of the booth.-e found his co"worker in contact with a single"strand wire from one of the lights. :eedle"nose wire stripperswere stuck in the left side of the victim%s chest. 5pparently, he had been stripping insulation from animproperly grounded D!0"volt, single"strand wire when he contacted it with the stripper. 8n this case, theelectricians knew they were working on energied circuits. &he breakers in the booth%s control panel werenot labeled and the lock used for lock"out;tag"out was broken. &he surviving electrician stated that locatingthe means to de"energie a circuit often takes more time than the actual 7ob.&he electrician would be alive today if the following rules had been observed.I 5lways shut off circuitsthen test to confirm that they are de"energiedbefore starting a 7ob.I witchgear that shuts off a circuit must be clearly labeled and easy to access.I ock"out;tag"out materials must always be provided, and lock"out;tag"out procedures must alwaysbe followed.

&l'ay tet a circuit to make ure it ide#energi1ed before 'orking on it9ock#outLtag#out a+e li+ePage % Section C

S&,02 MOD,9 S0&;, %/*ON05O99IN;

9ock#OutL0ag#Out *hecklit &oc'(out)tag(out is an essential safety procedure

that protects &or%ers from in=ury &hile &or%in6 on

or near electrical circuits and eDuipment5 Eoc%3outinvolves applyin6 a physical loc% to the po&er

source(s) of circuits and eDuipment after they have

been shut off and de3ener6i@ed5 The source is thenta66ed out &ith an easy3to3read ta6 that alerts other

&or%ers in the area that a loc% has been applied5

In addition to protectin6 &or%ers from electrical

ha@ards, loc%3out8ta63out prevents contact

&ith operatin6 eDuipment parts- blades, 6ears,

shafts, presses, etc5Also, loc%3out8ta63out prevents the une1pected

release of ha@ardous 6asses, fluids, or solid matter

in areas &here &or%ers are present5&n employee 'a cutting into a metal pipe uing ablo'torch Dieel fuel 'a mitakenly dichargedinto the line and 'a ignited by hi torch 0he'orker burned to death at the cene&ll +al+e along the line hould ha+e been lockedout3 blanked out3 and tagged out to pre+ent thereleae of fuel =lanking i the proce of inertinga metal dik into the pace bet'een t'o pipeflange 0he dik3 or blank3 i then bolted in place



to pre+ent paage of li:uid or gae throughthe pipe& 'orker 'a replacing a J#belt on a dut collector blo'er =efore beginning 'ork3 he hut do'n theunit at the local 'itch Ho'e+er3 an operator in thecontrol room retarted the unit uing a remote'itch 0he 'orkerA hand 'a caught bet'een the

pulley and belt of the blo'er3 reulting in cut anda fractured fingerWhen performing lock#outLtag#out on machinery3you mut al'ay lock out and tag out &99 energyource leading to the machinery

*hen 0erfor+ing [email protected] on circuits

and eAui0+ent/ you can use the checklist belo

4 Identify all sources of electrical ener6y for the

eDuipment or circuits in Duestion5

4 isable bac%up ener6y sources such as 6enerators

and batteries5

4 Identify all shut3offs for each ener6y source5

4 Notify all personnel that eDuipment and

circuitry must be shut off, loc%ed out, andta66ed out5 (Simply turnin6 a s&itch off is

NOT enou6h5)

4 Shut off ener6y sources and loc% s&itch6ear

in the O?? position5 2ach &or%er should

apply his or her individual loc%5 o not 6ive

your %ey to anyone5

4 Test eDuipment and circuitry to ma%e sure

they are de3ener6i@ed5 This must be done by a

Dualified person5R

4 eplete stored ener6y by bleedin6, bloc%in6,

6roundin6, etc5

4 Apply a ta6 to alert other &or%ers that anener6y source or piece of eDuipment has been

loc%ed out5

4 9a%e sure everyone is safe and accounted for

before eDuipment and circuits are unloc%edand turned bac% on5 Note that only a Dualified

person may determine &hen it is safe to reener6i@e

circuits5

ROSHA defines a KDualified personL as someone &ho has

received mandated trainin6 on the ha@ards and on the

construction and operation of eDuipment involved in a tas%5

*ontrol inade:uate 'iring ha1ard2lectrical ha@ards result from usin6 the &ron6 si@e or type of &ire5?ou must control such ha@ards to create a safe &or% environment5

?ou must choose the ri6ht si@e &ire for the amount of current

e1pected in a circuit5 The &ire must be able to handle the current

safely5 The &ireGs insulation must be appropriate for the volta6e and

tou6h enou6h for the environment5 $onnections need to be reliable

and protected5z <e the right i1e and type of 'ire



z &W;/&merican Wire ;auge

a measure of wire sie

Section C Page %G

H&K&5DS S&, WO5 ,NJI5ONM,N0$> &W; $! &W; $! &W; $" &W; &W; B &W; ! &W; $L" &W;(tranded) (olid)!" amp !@ amp %" amp >" amp @@ amp G@ amp $!@ amp

Wire come in different i1e 0he ma4imum current each i1e can conduct afely iho'n

*ontrol ha1ard of fi4ed 'iringThe &irin6 methods and si@e of conductors used in a system depend

on several factors-

q Intended use of the circuit system

q Cuildin6 materials

q Si@e and distribution of electrical load

q Eocation of eDuipment (such as under6round burial)

q 2nvironmental conditions (such as dampness)

q Presence of corrosives

q Temperature e1tremes

0i1ed, permanent &irin6 is better than e1tension cords, &hich can be

misused and dama6ed more easily5 N2$ reDuirements for fi1ed

&irin6 should al&ays be follo&ed5 A variety of materials can be

used in &irin6 applications, includin6 nonmetallic sheathed cable

(<ome1), armored cable, and metal and plastic conduit5 The

choice of &irin6 material depends on the &irin6 environment and

the need to support and protect &ires5

Aluminum &ire and connections should be handled &ith special

care5 $onnections made &ith aluminum &ire can loosen due to

heat e1pansion and o1idi@e if they are not made properly5 Eoose

or o1idi@ed connections can create heat or arcin65 Special clamps

and terminals are necessary to ma%e proper connections usin6

aluminum &ire5 Antio1idant paste can be applied to connections to prevent o1idation5

*ontrol ha1ard of fle4ible 'iring<e fle4ible 'iring properly2lectrical cords supplement fi1ed &irin6 by providin6 the fle1ibility

reDuired for maintenance, portability, isolation from vibration, and

emer6ency and temporary po&er needs5z fi4ed 'iring/the permanentwiring installed in homes andother buildings

Page >" Section C

S&,02 MOD,9 S0&;, %/*ON05O99IN;

Nonmetalic heathing help protect'ire from damage0le1ible &irin6 can be used for e1tension cords or po&er supply

cords5 Po&er supply cords can be removable or permanently

attached to the appliance5

DO <O9 use fle1ible &irin6 in situations &here freDuent inspection

&ould be difficult, &here dama6e &ould be li%ely, or &here lon6term

electrical supply is needed5 0le1ible cords cannot be used as

a substitute for the fi1ed &irin6 of a structure5 0le1ible cords must



not be 5 5 5

q run throu6h holes in &alls, ceilin6s, or floors

q run throu6h door&ays, &indo&s, or similar openin6s (unless

physically protected)

q attached to buildin6 surfaces (e1cept &ith a tension ta%e3up

device &ithin " feet of the supply end)

q hidden in &alls, ceilin6s, or floors or q hidden in conduit or other race&ays5z fle4ible 'iring/cables withinsulated and stranded wire thatbends easilyz DonAt ue fle4ible 'iring 'here itmay get damaged

Section C Page >$


&2H"year"old male welder was assigned to work on an outdoor concrete platform attached to the

main factory building. -e wheeled a portable arc welder onto the platform. ince there was not anelectrical outlet nearby, he used an e'tension cord to plug in the welder. &he male end of the cordhad four prongs, and the female end was spring"loaded. &he worker plugged the male end of the cord intothe outlet. -e then plugged the portable welder%s power cord into the female end of the e'tension cord. 5tthat instant, the metal case around the power cord plug became energied, electrocuting the worker.

5n investigation showed that the female end of the e'tension cord was broken. &he spring, cover plate,and part of the casing were missing from the face of the female connector. 5lso, the grounding prong onthe welder%s power cord plug was so severely bent that it slipped outside of the connection. &herefore, thearc welder was not grounded. :ormally, it would have been impossible to insert the plug incorrectly. 4ut,since the cord%s female end was damaged, the bad3 connection was able to occur.<o not let this happen to you. se these safe practices? &horoughly inspect all electrical e$uipment before beginning work.? <o not use e'tension cords as a substitute for fi'ed wiring. 8n this case, a weatherproof receptacleshould have been installed on the platform.? se connectors that are designed to stand up to the abuse of the 7ob. Connectors designed for

light"duty use should not be used in an industrial environment.<e the right e4tenion cordThe si@e of &ire in an e1tension cord must be compatible &ith the

amount of current the cord &ill be e1pected to carry5 The amount of

current depends on the eDuipment plu66ed into the e1tension cord5

$urrent ratin6s (ho& much current a device needs to operate) are

often printed on the nameplate5 If a po&er ratin6 is 6iven, it is necessary

to divide the po&er ratin6 in &atts by the volta6e to find the current

ratin65 0or e1ample, a *,...3&att heater plu66ed into a *.3volt

circuit &ill need almost *. amps of current5 EetGs loo% at another

e1ample- A *3horsepo&er electric motor uses electrical ener6y at the

rate of almost #'. &atts, so it &ill need a minimum of about # amps

of current on a *.3volt circuit5 Cut, electric motors need additionalcurrent as they startup or if they stall, reDuirin6 up to .. of the

nameplate current ratin65 Therefore, the motor &ould need *! amps5

Add to find the total current needed to operate all the appliances

supplied by the cord5 $hoose a &ire si@e that can handle the total

current5

:+erican *ire ;auge :*;

<emember- The larger the 6au6e number, the

smaller the &ire



The len6th of the e1tension cord also needs to be considered &hen

selectin6 the &ire si@e5 Qolta6e drops over the len6th of a cord5 If a

cord is too lon6, the volta6e drop can be enou6h to dama6e eDuipment5

9any electric motors only operate safely in a narro& ran6e of

volta6es and &ill not &or% properly at volta6es different than thevolta6e listed on the nameplate5 2ven thou6h li6ht bulbs operate

(some&hat dimmer) at lo&ered volta6es, do not assume electricmotors &ill &or% correctly at less3than3reDuired volta6es5 Also,

&hen electric motors start or operate under load, they reDuire more

current5 The lar6er the si@e of the &ire, the lon6er a cord can be

&ithout causin6 a volta6e drop that could dama6e tools and

eDuipment5

Wire i1e$" &W;$! &W;$> &W;$B &W;

Handle up to%" amp!@ amp$ amp$% ampz po'er/the amount of energy usedin a second, measured in wattsz $ horepo'er C>B 'attz Do not ue e4tenion cord thatare too long for the i1e of 'ire

Page >! Section C

S&,02 MOD,9 S0&;, %/*ON05O99IN;The 6roundin6 path for e1tension cords must be %ept intact to %eep

you safe5 A typical e1tension cord 6roundin6 system has four components-

q a third &ire in the cord, called a 6round &ire

q a three3pron6 plu6 &ith a 6roundin6 pron6 on one

end of the cord

q a three3&ire, 6roundin63type receptacle at the other end

of the cord and

q a properly 6rounded outlet5

*ontrol ha1ard of e4poed li+e electricalpart iolate energi1ed component2lectrical ha@ards e1ist &hen &ires or other electrical parts are

e1posed5 These ha@ards need to be controlled to create a safe &or% environment5 Isolation of ener6i@ed electrical parts ma%es them inaccessible

unless tools and special effort are used5 Isolation can be

accomplished by placin6 the ener6i@ed parts at least feet hi6h and

out of reach, or by 6uardin65 Fuardin6 is a type of isolation that uses

various structures—li%e cabinets, bo1es, screens, barriers, covers, and partitions—to close3off live electrical parts5z Make ure the path to ground icontinuou



z guarding/a covering or barrier that

separates you from liveelectrical parts

Section C Page >%

H&K&5DS S&, WO5 ,NJI5ONM,N0Outlet mut be

grounded properly0hi e4poed electrical e:uipment i guardedby an #foot fence <e co+er to pre+entaccidental contact 'ithelectrical circuitTa%e the follo&in6 precautions to prevent in=uries from contact &ith

live parts-

q Immediately report e1posed live parts to a supervisor or teacher5

As a student, you should never attempt to correct the condition

yourself &ithout supervision5

q Provide 6uards or barriers if live parts cannot be enclosed

completely5

q >se covers, screens, or partitions for 6uardin6 that reDuire toolsto remove them5

q <eplace covers that have been removed from panels, motors, or

fuse bo1es5

q 2ven &hen live parts are elevated to the reDuired hei6ht ( feet),

care should be ta%en &hen usin6 ob=ects (li%e metal rods or

pipes) that can contact these parts5

q $lose unused conduit openin6s in bo1es so that forei6n ob=ects

(pencils, metal chips, conductive debris, etc5) cannot 6et inside

and dama6e the circuit5

*ontrol ha1ard of e4poure to li+eelectrical 'ire ue proper inulationInsulation is made of material that does not conduct electricity(usually plastic, rubber, or fiber)5 Insulation covers &ires and prevents

Page >> Section C

S&,02 MOD,9 S0&;, %/*ON05O99IN;

&20"year"old male laborer was carrying a 20"foot piece of iron from a welding shop to an outside

storage rack. 5s he was turning a corner near a bank of electrical transformers, the top end of thepiece of iron struck an uninsulated supply wire at the top of a transformer. 5lthough the transformerswere surrounded by a F"foot fence, they were about ! feet taller than the fence enclosure. /achtransformer carried B,F0 volts.#hen the iron hit the supply wire, the laborer was electrocuted. 5 forklift operator heard the iron drop to

the ground at about NBF a.m. and found the victim D minutes later. -e was pronounced dead on arrivalat a local hospital.I 5ccording to K-5, the enclosure around the transformers was too short. &he fence should have beenat least N feet tall.I &he company in this case did not offer any formal safety training to its workers. 5ll employers shoulddevelop safety and health training programs so their employees know how to recognie and avoid lifethreateninghaards.

0hi co+er cannot be remo+ed'ithout pecial toolconductors from comin6 in contact &ith each other or any other



conductor5 If conductors are allo&ed to ma%e contact, a short circuit

is created5 In a short circuit, current passes throu6h the shortin6

material &ithout passin6 throu6h a load in the circuit, and the &ire

becomes overheated5 Insulation %eeps &ires and other conductors

from touchin6, &hich prevents electrical short circuits5 Insulation prevents live &ires from touchin6 people and animals, thus protectin6

them from electrical shoc%5Insulation helps protect &ires from physical dama6e and conditions

in the environment5 Insulation is used on almost all &ires, e1cept

some 6round &ires and some hi6h3volta6e transmission lines5

Insulation is used internally in tools, s&itches, plu6s, and other electrical

and electronic devices5

Special insulation is used on &ires and cables that are used in harsh

environments5 7ires and cables that are buried in soil must have an

outer coverin6 of insulation that is flame3retardant and resistant to

moisture, fun6us, and corrosion5

In all situations, you must be careful not to dama6e insulation &hile

installin6 it5 o not allo& staples or other supports to dama6e the

insulation5 Cends in a cable must have an inside radius of at leastz Make ure inulation i the righttype and in good condition

Section C Page >@


&2H"year"old male maintenance worker was found at !BD a.m. lying on his back and convulsing.

4eside him were an overturned cart and an electric welding machine, both lying in a pool of water on the concrete floor. 5rcing was visible between the welding machine and the floor. &he worker was transported to the closest hospital, where he was pronounced dead.

5n e'amination of the welding machine showed that there were e'posed conductors in the machine%scables. &here were numerous cuts and scrapes in the cables% insulation. Kn other parts of the machine,

insulation was damaged or missing. 5lso, the machine did not have a ground connection.8nvestigators concluded that the maintenance worker was electrocuted when he tried to turn off the weldingmachine, which was sitting on the cart. &he metal frame of the machine had become energied due tothe damaged insulation. #hen he touched the energied frame, he completed the conducting path toground. &he current traveled through his body to ground. ince he was probably standing in water, the riskof a ground fault was even greater.6ou must take steps to decrease such haards in your workplace? Lround circuits and e$uipment.? Oeep all e$uipment in good operating condition with a preventive maintenance program.? :ever use electrical e$uipment or work on circuits in wet areas. 8f you find water or dampness, notifyyour supervisor immediately.

' times the diameter of the cable so that insulation at a bend is not

dama6ed5 21tension cords come &ith insulation in a variety of types

and colors5 The insulation of e1tension cords is especially important5

Since e1tension cords often receive rou6h handlin6, the insulationcan be dama6ed5 21tension cords mi6ht be used in &et places, so

adeDuate insulation is necessary to prevent shoc%s5 Cecause e1tension

cords are often used near combustible materials (such as &ood

shavin6s and sa&dust) a short in an e1tension cord could easilycause arcin6 and a fire5

Insulation on individual &ires is often color3coded5 In 6eneral, insulated

&ires used as eDuipment 6roundin6 conductors are either continuous



6reen or 6reen &ith yello& stripes5 The 6rounded conductors

that complete a circuit are 6enerally covered &ith continuous &hite

or 6ray insulation5 The un6rounded conductors, or KhotL &ires, may

be any color other than 6reen, &hite, or 6ray5 They are usually blac%

or red5$onductors and cables must be mar%ed by the manufacturer to sho&

the follo&in6-q ma1imum volta6e capacity,

q A7F si@e,

q insulation3type letter, and

q the manufacturerGs name or trademar%5

*ontrol ha1ard of hocking current;round circuit and e:uipment7hen an electrical system is not 6rounded properly, a ha@ard e1ists5

This is because the parts of an electrical &irin6 system that a person

normally touches may be ener6i@ed, or live, relative to 6round5 Parts

li%e s&itch plates, &irin6 bo1es, conduit, cabinets, and li6hts need to

be at . volts relative to 6round5 If the system is 6rounded improperly,

these parts may be ener6i@ed5 The metal housin6s of eDuipment

plu66ed into an outlet need to be 6rounded throu6h the plu65

Page >B Section C

S&,02 MOD,9 S0&;, %/*ON05O99IN;;round electricalde+ice&rc#fault circuitbreakerFroundin6 is connectin6 an electrical system to the earth &ith a &ire5

21cess or stray current travels throu6h this &ire to a 6roundin6

device (commonly called a K6roundL) deep in the earth5 Froundin6

prevents un&anted volta6e on electrical components5 9etal plumbin6

is often used as a 6round5 7hen plumbin6 is used as a 6roundin6

conductor, it must also be connected to a 6roundin6 device such as a

conductive rod5 (<ods used for 6roundin6 must be driven at least feet into the earth5) Sometimes an electrical system &ill receive a

hi6her volta6e than it is desi6ned to handle5 These hi6h volta6es may

come from a li6htnin6 stri%e, line sur6e, or contact &ith a hi6hervolta6e

line5 Sometimes a defect occurs in a device that allo&s

e1posed metal parts to become ener6i@ed5 Froundin6 &ill help

protect the person &or%in6 on a system, the system itself, and others

usin6 tools or operatin6 eDuipment connected to the system5 The

e1tra current produced by the e1cess volta6e travels relatively safely

to the earth5

Froundin6 creates a path for currents produced by unintended

volta6es on e1posed parts5 These currents follo& the 6roundin6 path,

rather than passin6 throu6h the body of someone &ho touches the

ener6i@ed eDuipment5 Ho&ever, if a 6roundin6 rod ta%es a direct hit

from a li6htnin6 stri%e and is buried in sandy soil, the rod should bee1amined to ma%e sure it &ill still function properly5 The heat from

a li6htnin6 stri%e can cause the sand to turn into 6lass, &hich is an

insulator5 A 6roundin6 rod must be in contact &ith damp soil to be



effective5

Eea%a6e current occurs &hen an electrical current escapes from its

intended path5 Eea%a6es are sometimes lo&3current faults that can

occur in all electrical eDuipment because of dirt, &ear, dama6e, or

moisture5 A 6ood 6roundin6 system should be able to carry off thislea%a6e current5 A 6round fault occurs &hen current passes throu6h

the housin6 of an electrical device to 6round5 Proper 6roundin6 protectsa6ainst 6round faults5 Fround faults are usually caused by

misuse of a tool or dama6e to its insulation5 This dama6e allo&s a

bare conductor to touch metal parts or the tool housin65

7hen you 6round a tool or electrical system, you create a lo&resistance

path to the earth (%no&n as a 6round connection)5 7hen

done properly, this path has sufficient current3carryin6 capacity to

eliminate volta6es that may cause a dan6erous shoc%5

Froundin6 does not 6uarantee that you &ill not be shoc%ed, in=ured,

or %illed from defective eDuipment5 Ho&ever, it 6reatly reduces the

possibility5

Section C Page >C

H&K&5DS S&, WO5 ,NJI5ONM,N0;rounding#typereceptacle;rounding rod inthe earth2Duipment needs to be 6rounded under any of these circumstances-

q The eDuipment is &ithin feet vertically and ' feet hori@ontally

of the floor or &al%in6 surface5

q The eDuipment is &ithin feet vertically and ' feet hori@ontally

of 6rounded metal ob=ects you could touch5

q The eDuipment is located in a &et or damp area and is not isolated5

q The eDuipment is connected to a po&er supply by cord and plu6

and is not double3insulated5<e ;*IAThe use of F0$IGs has lo&ered the number of electrocutions dramatically5

A F0$I is a fast3actin6 s&itch that detects any difference in

current bet&een t&o circuit conductors5 If either conductor comes in

contact—either directly or throu6h part of your body—&ith a

6round (a situation %no&n as a 6round fault), the F0$I opens the

circuit in a fraction of a second5 If a current as small as ! to " mA

does not pass throu6h both &ires properly, but instead lea%s to the

6round, the F0$I is tripped5 The current is shut off5

There is a more sensitive %ind of F0$I called an isolation F0$I5 If

a circuit has an isolation F0$I, the 6round fault current passes

throu6h an electronic sensin6 circuit in the F0$I5 The electronicsensin6 circuit has enou6h resistance to limit current to as little as mA, &hich is too lo& to cause a dan6erous shoc%5

F0$IGs are usually in the form of a duple1 receptacle5 They are also

available in portable and plu63in desi6ns and as circuit brea%ers

that protect an entire branch circuit5 F0$IGs can operate on both

t&o3 and three3&ire 6round systems5 0or a F0$I to &or% properly,

the neutral conductor (&hite &ire) must (*) be continuous, () have

lo& resistance, and (/) have sufficient current3carryin6 capacity5



F0$IGs help protect you from electrical shoc% by continuously monitorin6

the circuit5 Ho&ever, a F0$I does not protect a person from

line3to3line ha@ards such as touchin6 t&o KhotL &ires (!. volts) at

the same time or touchin6 a KhotL and neutral &ire at the same time5

Also be a&are that instantaneous currents can be hi6h &hen a F0$Iis tripped5 A shoc% may still be felt5 ?our reaction to the shoc% could

cause in=ury, perhaps from fallin65Test F0$IGs re6ularly by pressin6 the KtestL button5 If the circuit

does not turn off, the F0$I is faulty and must be replaced5z ;*IA ha+e their limitation

Page > Section C

S&,02 MOD,9 S0&;, %/*ON05O99IN;Portable ;*IThe N2$ reDuires that F0$IGs be used in these hi6h3ris% situations-

q 2lectricity is used near &ater5

q The user of electrical eDuipment is 6rounded (by touchin6

6rounded material)5

q $ircuits are providin6 po&er to portable tools or outdoor

receptacles5q Temporary &irin6 or e1tension cords are used5

Specifically, F0$IGs must be installed in bathrooms, 6ara6es, outdoor

areas, cra&l spaces, unfinished basements, %itchens, and near

&et bars5

=ond component to aure grounding pathIn order to assure a continuous, reliable electrical path to 6round, a

bondin6 =umper &ire is used to ma%e sure electrical parts are connected5

Some physical connections, li%e metal conduit comin6 into az <e ;*IA to help protect peoplein damp areaz bonding/ 7oining electrical parts toassure a conductive path

Section C Page >GH&K&5DS S&, WO5 ,NJI5ONM,N0

&female assistant manager of a swim club was instructed to add a certain chemical to the pool. he

went down into the pump room, barefoot. &he room was below ground level, and the floor wascovered with water. he filled a plastic drum with !D"B0 gallons of water, then plugged a mi'ingmotor into a 20"volt wall outlet and turned on the motor. &he motor would be used to mi' the water andthe chemical, then the solution would be added to the pool. #hile adding the chemical to the water in thedrum, she contacted the mi'ing motor with her left hand. 5pparently, the motor had developed a groundfault. 4ecause of the ground fault, the motor was energied, and she was electrocuted. 5 co"worker foundthe victim slumped over the drum with her face submerged in water. &he co"worker tried to move thevictim but was shocked. &he assistant manager was dead on arrival at a local hospital.

5n investigation showed that the mi'ing motor was in poor condition. &he grounding pin had beenremoved from the male end of the power cord, resulting in a faulty ground. &he circuit was e$uipped witha L>C8, but it was not installed properly. 5 properly wired and functioning L>C8 could have sensed theground fault in the motor and de"energied the circuit.&ake a look at what could have been done to prevent this death.I &he employer should have kept the motor in better condition. *ower cords should be inspectedregularly, and any missing prongs should be replaced.I 5ll pool"area electrical circuits should be installed by $ualified electricians.I &he victim should have worn insulating boots or shoes since she was handling electrical e$uipment.I &he employer should have followed the law. &he :/C re$uires that all pool"associated motors have a



permanent grounding system. 8n this case, this regulation was not followed. 5lso, electrical e$uipmentis not permitted in areas without proper drainage.I K-5 re$uires employers to provide a work environment free of safety and health haards.

Intall bonding -umperaround nonconducti+ematerial

bo1, mi6ht not ma%e a 6ood electrical connection because of paintor possible corrosion5 To ma%e a 6ood electrical connection, a bondin6

=umper needs to be installed5A metal cold &ater pipe that is part of a path to 6round may need

bondin6 =umpers around plastic antivibration devices, plastic &ater

meters, or sections of plastic pipe5 A bondin6 =umper is made of

conductive material and is ti6htly connected to metal pipes &ith

scre&s or clamps to bypass the plastic and assure a continuous

6roundin6 path5 Condin6 =umpers are necessary because plastic does

not conduct electricity and &ould interrupt the path to 6round5

Additionally, interior metal plumbin6 must be bonded to the 6round

for electrical service eDuipment in order to %eep all 6rounds at the

same potential (. volts)5 2ven metal air ducts should be bonded to

electrical service eDuipment5

*ontrol o+erload current ha1ard7hen a current e1ceeds the current ratin6 of eDuipment or &irin6, a

ha@ard e1ists5 The &irin6 in the circuit, eDuipment, or tool cannot

handle the current &ithout heatin6 up or even meltin65 Not only &ill

the &irin6 or tool be dama6ed, but the hi6h temperature of the conductor

can also cause a fire5 To prevent this from happenin6, an

overcurrent protection device (circuit brea%er or fuse) is used in a

circuit5 These devices open a circuit automatically if they detect current

in e1cess of the current ratin6 of eDuipment or &irin65 This

e1cess current can be caused by an overload, short circuit, or hi6hlevel

6round fault5z bonding -umper/theconductor used to connectparts to be bonded

Page @" Section C

S&,02 MOD,9 S0&;, %/*ON05O99IN;<e o+ercurrent protection de+ice(circuit breaker or fue) in circuitOvercurrent protection devices are desi6ned to protect eDuipment

and structures from fire5 9hey do not 0rotect you fro+ electrical

shock> Overcurrent protection devices stop the flo& of current in a

circuit &hen the ampera6e is too hi6h for the circuit5 A circuit brea%er

or fuse &ill not stop the relatively small amount of current that

can cause in=ury or death5 eath can result from . mA (5.. amps)throu6h the chest (see Section )5 A typical residential circuit brea%er

or fuse &ill not shut off the circuit until a current of more than

. amps is reached

Cut overcurrent protection devices are not allo&ed in areas &here

they could be e1posed to physical dama6e or in ha@ardous environments5

Overcurrent protection devices can heat up and occasionallyarc or spar%, &hich could cause a fire or an e1plosion in certain



areas5 Ha@ardous environments are places that contain flammable or

e1plosive materials such as flammable 6asses or vapors ($lass I

Ha@ardous 2nvironments), finely pulveri@ed flammable dusts

($lass II Ha@ardous 2nvironments), or fibers or metal filin6s that

can catch fire easily ($lass III Ha@ardous 2nvironments)5 Ha@ardousenvironments may be found in aircraft han6ars, 6as stations, stora6e

plants for flammable liDuids, 6rain silos, and mills &here cottonfibers may be suspended in the air5 Special electrical systems are

reDuired in ha@ardous environments5

If an overcurrent protection device opens a circuit, there may be a

problem alon6 the circuit5 (In the case of circuit brea%ers, freDuent

trippin6 may also indicate that the brea%er is defective5) *hen a circuit

brea'er trips or a fuse blows+ the cause must be found .

A circuit brea%er is one %ind of overcurrent protection device5 It is a

type of automatic s&itch located in a circuit5 A circuit brea%er trips

&hen too much current passes throu6h it5 A circuit brea%er should

not be used re6ularly to turn po&er on or off in a circuit, unless the

brea%er is desi6ned for this purpose and mar%ed KS7L (stands for

Ks&itchin6 deviceL)5A fuse is another type of overcurrent protection device5 A fuse contains

a metal conductor that has a relatively lo& meltin6 point5

7hen too much current passes throu6h the metal in the fuse, it heats

up &ithin a fraction of a second and melts, openin6 the circuit5 After an overload is found and corrected, a blo&n fuse must be replaced

&ith a ne& one of appropriate ampera6e5z ind the caue of an o+erload

Section C Page @$

H&K&5DS S&, WO5 ,NJI5ONM,N0Only circuit breakermarked 7SWD8 hould

be ued a 'itchePage @! Section C

S&,02 MOD,9 S0&;, %/*ON05O99IN;

Summary of Section C$ontrol contact &ith electrical volta6es and control electrical currents to create a safe &or% environment5

Eoc% out and ta6 out circuits and machines5

Prevent overloaded &irin6 by usin6 the ri6ht si@e and type of &ire5

Prevent e1posure to live electrical parts by isolatin6 them5

Prevent e1posure to live &ires and parts by usin6 insulation5

Prevent shoc%in6 currents from electrical systems and tools by 6roundin6 them5

Prevent shoc%in6 currents by usin6 F0$IGs5

Prevent too much current in circuits by usin6 overcurrent protection devices5

Section C Page @%H&K&5DS S&, WO5 ,NJI5ONM,N0

Section Safety Model Stage %/*ontrolling Ha1ardSafe Work Practice



Ho' Do 2ou Work Safely6A safe &or% environment is not enou6h to control all electrical ha@ards5

?ou must also &or% safely5 Safe &or% practices help you control

your ris% of in=ury or death from &or%place ha@ards5 If you are

&or%in6 on electrical circuits or &ith electrical tools and eDuipment,

you need to use safe &or% practices5

Cefore you be6in a tas%, as% yourself-

q 7hat could 6o &ron6B

q o I have the %no&led6e, tools, and e1perience to do this &or%

safelyB

All &or%ers should be very familiar &ith the safety procedures

for their =obs5 ?ou must %no& ho& to use specific controls that help

%eep you safe5 ?ou must also use 6ood =ud6ment and common

sense5

$ontrol electrical ha@ards throu6h safe &or% practices5

q Plan your &or% and plan for safety5

q Avoid &et &or%in6 conditions and other dan6ers5

q Avoid overhead po&erlines5

q >se proper &irin6 and connectors5

q >se and maintain tools properly5

q 7ear correct PP25

Page @> Section

S&,02 MOD,9 S0&;, %/*ON05O99IN;

Plan your 'ork and plan for afetyTa%e time to plan your &or%, by yourself and &ith others5 Safety

plannin6 is an important part of any tas%5 It ta%es effort to reco6ni@e,

evaluate, and control ha@ards5 If you are thin%in6 about your &or%

tas%s or about &hat others thin% of you, it is hard to ta%e the time to

plan for safety5 Cut, 5O !S9 -7:<5

Plannin6 &ith others is especially helpful5 It allo&s you to coordinateyour &or% and ta%e advanta6e of &hat others %no& about identifyin6

and controllin6 ha@ards5 The follo&in6 is a list of somethin6s to thin% about as you plan5

q *ork ith a buddy —o not &or% alone5 Coth of you

should be trained in $P<5 Coth of you must %no& &hat to do

in an emer6ency5

q no ho to shut off and de.energi%e circuits —?ou must find

&here circuit brea%ers, fuses, and s&itches are located5 Then, the

circuits that you &ill be &or%in6 on (even lo&3volta6e circuits)

!S9 BE 9$<ED O??> Test the circuits before be6innin6

&or% to ma%e sure they are completely de3ener6i@ed5z Plan to be afez DonAt 'ork alone

Section Page @@

H&K&5DS S&, WO5 P5&*0I*,S

&B0"year"old male meter technician had 7ust completed a 1"week basic lineman training course. -e

worked as a meter technician during normal working hours and as a lineman during unplanned outages.Kne evening, he was called to repair a residential power outage. 4y the time he arrived at



the site of the outage, he had already worked 2 hours of overtime and worked B straight hours the daybefore. 5t the site, a tree limb had fallen across an overhead powerline. &he neutral wire in the line wassevered, and the two energied 20"volt wires were disconnected. &he worker removed the tree limb andclimbed up a power pole to reconnect the three wires. -e was wearing insulated gloves, a hard hat, andsafety glasses.-e prepared the wires to be connected. #hile handling the wires, one of the energied wires caught thecuff of his left glove and pulled the cuff down. &he conductor contacted the victim%s forearm near the wrist.

-e was electrocuted and fell backwards. -e was wearing a climbing belt, which left him hanging upsidedown from the pole. *aramedics arrived D minutes after the contact. &he power company lowered his deadbody !0 minutes later.everal factors may have contributed to this incident. 4elow are some ways to eliminate these risk factors.I 5sk for assistance when you are assigned tasks that cannot be safely completed alone. &he taskassigned to the victim could not have been done safely by only one person.I <o not work overtime performing haardous tasks that are not part of your normal assignments.I /mployees should only be given tasks that they are $ualified to perform. 5ll employees below the

7ourneyman level should be supervised.

q -lan to lock out and tag out circuits and eAui0+ent —9a%e

certain all ener6y sources are loc%ed out and ta66ed out before

performin6 any &or% on an electrical circuit or electrical device5

7or%in6 on ener6i@ed (KhotL) circuits is one of the most dan6erous

thin6s any &or%er could do5 If someone turns on a circuit

&ithout &arnin6, you can be shoc%ed, burned, or electrocuted5The une1pected startin6 of electrical eDuipment can cause severe

in=ury or death5

Cefore :<5 &or% is done on a circuit, shut off the circuit, loc%

out and ta6 out the circuit at the distribution panel, then test the

circuit to ma%e sure it is de3ener6i@ed5

Cefore :<5 eDuipment inspections or repairs—even on so3called

lo&3volta6e circuits—the current must be turned off at the s&itch

bo1, and the s&itch must be padloc%ed in the O00 position5 At

the same time, the eDuipment must be securely ta66ed to &arneveryone that &or% is bein6 performed5 A6ain, test circuits and

eDuipment to ensure they are de3ener6i@ed5

No t&o loc%s should be ali%e5 2ach %ey should fit only one loc%,and only one %ey should be issued to each &or%er5 If more than

one &or%er is &or%in6 on a circuit or repairin6 a piece of eDuipment,

each &or%er should loc% out the s&itch &ith his or her o&n

loc% and never permit anyone else to remove it5 At all times, you

must be certain that you are not e1posin6 other &or%ers to dan6er5

7or%ers &ho perform loc%3out8ta63out must be trained and

authori@ed to repair and maintain electrical eDuipment5 A loc%edout

s&itch or feeder panel prevents others from turnin6 on a circuit5

The ta6 informs other &or%ers of your action5

q $e+ove 6eelry and +etal ob6ects —<emove =e&elry and other

metal ob=ects or apparel from your body before be6innin6 &or%5

These thin6s can cause burns if &orn near hi6h currents and can6et cau6ht as you &or%5

q -lan to avoid falls —In=uries can result from fallin6 off scaffoldin6

or ladders5 Other &or%ers may also be in=ured from eDuipmentand debris fallin6 from scaffoldin6 and ladders5

Page @B Section

S&,02 MOD,9 S0&;, %/*ON05O99IN;0hi 'orker i



applying a grouplock#out de+ice 0hee:uipment cannotbe re#tarted untilall 'orker remo+etheir lock

Section Page @CH&K&5DS S&, WO5 P5&*0I*,S

&worker was attempting to correct an electrical problem involving two non"operational lamps. -e

e'amined the circuit in the area where he thought the problem was located. -e had not shut off thepower at the circuit breaker panel and did not test the wires to see if they were live. -e was electrocutedwhen he grabbed the two live wires with his left hand. -e collapsed to the floor and was founddead.I /mployers should not allow work to be done on electrical circuits unless an effective lock"out;tag"outprogram is in place.I :o work should be done on energied electrical circuits. Circuits must be shut off, locked out, andtagged out. /ven then, you must test the circuit before beginning work to confirm that it is

de"energied (dead3).!CC JO90 9&MPS<S, =O

To prevent in=ury &hen climbin6, follo& these procedures-

*5 Position the ladder at a safe an6le to prevent slippin65 The hori@ontal

distance from the base of the ladder to the structure should

be one3Duarter the len6th of the ladder5 If you donGt have a &ay

to ma%e this measurement, follo& the steps belo& to determine if

the ladder is positioned at a safe an6le5

4 Put your feet at the base of the ladder and e1tend your arms

strai6ht out5

4 If you can touch the closest part of the ladder &ithout bendin6

your arms, the ladder is probably at the correct an6le54 If you have to bend your arms to touch the closest part of the

ladder or if you canGt reach the ladder at all, the ladder is not

positioned at a safe an6le5

5 9a%e sure the base of the ladder has firm support and the 6round

or floor is level5 Ce very careful &hen placin6 a ladder on &et,

icy, or other&ise slippery surfaces5 Special bloc%in6 may be

needed to prevent slippin6 in these cases5

/5 0ollo& the manufacturerGs

recommendations for

proper use5

!5 $hec% the condition of the

ladder before usin6 it5 ;ointsmust be ti6ht to prevent

&obblin6 or leanin65

Page @ Section

9adder Safety act Sheet'5 7hen usin6 a stepladder, ma%e sure it is level and fully open5

Al&ays loc% the hin6es5 o not stand on or above the top step5

"5 7hen usin6 scaffoldin6, use a ladder to access the tiers5 Never



climb the cross braces5

#5 o not use metal ladders5 Instead, use ladders made of fiber6lass5

(Althou6h &ooden ladders are permitted, &ood can soa% up &ater

and become conductive5)

5 Ce&are of overhead po&erlines &hen you &or% &ith ladders andscaffoldin65

9earn ho' to ue ladder and caffolding properlySection Page @GPage B" Section

S&,02 MOD,9 S0&;, %/*ON05O99IN;q Do not do any tasks that you are not trained to do or that you

do not feel co+fortable doing>

&crew of 1 workers was painting a !!"foot sign at a shopping mall. &he crew used tubular

welded frame scaffolding that was ! feet tall and made up of several tiers. &he sign waspartially painted when the crew was instructed to move the scaffolding so that concrete could be

poured for an access road. &he crew moved the scaffolding !0 feet without disassembling it. 5n overheadpowerline was located about 0 feet away from the scaffolding. 5fter the concrete hardened, the workers liftedthe scaffolding to move it back to the sign. &he top tier came loose, fell, and contacted the powerline. 5llseven workers were knocked away from the scaffolding. &wo died? five were hospitalied.6ou must take certain precautions when working with scaffolding.? caffolding should not be moved until all potential safety haards are identified and controlled. 8n this case,the scaffolding should have been taken apart before it was moved.? ocking pins must be used to secure tiers to one another.? 5lways make sure you have enough time to complete your assignment safely. 8f you are rushed, you maybe more likely to take deadly short"cuts (such as failing to dismantle scaffolding before moving it).? /mployers must have a written safety program that includes safe work procedures and haard recognition.

&company was contracted to install wiring and fi'tures in a new office comple'. &he third floor was

being prepared in a hurry for a new tenant, and daily changes to the electrical system blueprintswere arriving by fa'. &he light fi'tures in the office were mounted in a metal grid that was fastenedto the ceiling and properly grounded.

5 2!"year"old male apprentice electrician was working on a light fi'ture when he contacted an energiedconductor. -e came down from the fiberglass ladder and collapsed. 5pparently, he had contacted the hot3conductor while also in contact with the metal grid. Current passed through his body and into the groundedgrid. Current always takes a path to ground. 8n this case, the worker was part of that path.-e was dead on arrival at a nearby hospital. ater, an investigation showed that the victim had cross"wiredthe conductors in the fi'ture by mistake. &his incorrect wiring allowed electricity to flow from a live circuiton the completed section of the building to the circuit on which the victim was working.4elow are some safety procedures that should have been followed in this case. 4ecause they wereignored, the 7ob ended in death.I 4efore work begins, all circuits in the immediate work area must be shut off, locked out, and taggedoutthen tested to confirm that they are de"energied.

I #iring done by apprentice electricians should be checked by a 7ourneyman.I 5 supervisor should always review changes to an original blueprint in order to identify any new haardsthat the changes might create.

Section Page B$

&+oid 'et 'orking conditionand other danger<emember that any ha@ard becomes much more dan6erous in damp

or &et conditions5 To be on the safe side, assume there is dampness

in any &or% location, even if you do not see &ater5 2ven s&eat can



create a damp condition

q Do not ork et —o not &or% on circuits or use electrical

eDuipment in damp or &et areas5 If necessary, clear the area of loose material or han6in6 ob=ects5 $over &et floors &ith &ooden

plan%in6 that can be %ept dry5 7ear insulatin6 rubber boots or

shoes5 ?our hands must be dry &hen plu66in6 and unplu66in6

po&er cords and e1tension cords5 o not 6et cleanin6 solutionson ener6i@ed eDuipment5

q se a ;?CI —Al&ays use a F0$I &hen usin6 portable tools and

e1tension cords5

&+oid o+erhead po'erlineCe very careful not to contact overhead po&erlines or other e1posed

&ires5 9ore than half of all electrocutions are caused by contact

&ith overhead lines5 7hen &or%in6 in an elevated position near

overhead lines, avoid locations &here you (and any conductive

ob=ect you hold) could contact an un6uarded or uninsulated line5

?ou should be at least *. feet a&ay from hi6h3volta6e transmission

lines5

Qehicle operators should also pay attention to overhead &irin65

ump truc%s, front3end loaders, and cranes can lift and ma%e

contact &ith overhead lines5 If you contact eDuipment that is

touchin6 live &ires, you &ill be shoc%ed and may be %illed5 If you

are in the vehicle, stay inside5 Al&ays be a&are of &hat is 6oin6 on

around you5

<e proper 'iring and connectorq :void overloads —o not overload circuits5

q 9est ;?CIFs —Test F0$IGs monthly usin6 the KtestL button5z &+oid 'et condition. ,+en a+oiddamp condition.

H&K&5DS S&, WO5 P5&*0I*,SPortable ;*IPage B! Section

S&,02 MOD,9 S0&;, %/*ON05O99IN;q Check sitches and insulation —Tools and other eDuipment

must operate properly5 9a%e sure that s&itches and insulatin6

parts are in 6ood condition5

q se three.0rong 0lugs —Never use a three3pron6 6roundin6

plu6 &ith the third pron6 bro%en3off5 7hen usin6 tools that

reDuire a third3&ire 6round, use only three3&ire e1tension cords

&ith three3pron6 6roundin6 plu6s and three3hole electrical outlets5

Never remove the 6roundin6 pron6 from a plu6 ?ou could

be shoc%ed or e1pose someone else to a ha@ard5 If you see a cord

&ithout a 6roundin6 pron6 in the plu6, remove the cord from

service immediately5

q se eGtension cords 0ro0erly —If an e1tension cord must be

used, choose one &ith sufficient ampacity for the tool bein6 used5

An undersi@ed cord can overheat and cause a drop in volta6e and

tool po&er5 $hec% the tool manufacturerGs recommendations for

the reDuired &ire 6au6e and cord len6th5 9a%e sure the insulation

is intact5 To reduce the ris% of dama6e to a cordGs insulation, use



&worker from an electrical service company was changing bulbs in pole"mounted light fi'tures in a shopping

center parking lot. &he procedure for installing the bulbs was as follows &he worker would parkthe truck near the first light pole. &he truck was e$uipped with a roof"mounted ladder. &he worker woulde'tend the ladder high enough to change the bulb, then drive to the ne't pole without lowering the ladder.

5fter the worker replaced the first bulb, he got back in the truck and drove toward the ne't light pole. 5s thetruck moved along, a steel cable attached to the top of the ladder contacted an overhead powerline. &he worker realied something was wrong, stopped the truck, and stepped onto the pavement while still holding ontothe door of the truck. 4y doing this, he completed the path to ground for the current in the truck. 4ecause theladder was still in contact with the powerline, the entire truck was now energied. -e was engulfed in flamesas the truck caught fire. >ire, police, and paramedic units arrived within D minutes. tility workers arrived inabout 0 minutes and de"energied (shut off) the powerline. &he victim burned to death at the scene.4elow are some ways to prevent contact with overhead powerlines.? 5 safe distance must be maintained between ladders (and other e$uipment) and overhead lines. K-5re$uires that a clearance of at least 0 feet be maintained between aerial ladders and overhead powerlinesof up to D0,000 volts.? oving a truck with the ladder e'tended is a dangerous practice. Kne way to control this haard is to installan engine lock that prevents a truck%s engine from starting unless the ladder is fully retracted.? 8f there are overhead powerlines in the immediate area, lighting systems that can be serviced from groundlevel are recommended for safety.

? 8f the worker had been trained properly, he may have known to stay inside the truck.? *re"7ob safety surveys should always be performed to identify and control haards. 8n this case, a surveywould have identified the powerlines as a possible haard, and appropriate haard control measures (suchas lowering the ladder between installations) could have been taken.

Ne+er ue a three#pronggrounding plug 'ith the thirdprong broken offcords &ith insulation mar%ed KSL (hard service) rather than cords

mar%ed KS;L (=unior hard service)5 9a%e sure the 6roundin6

pron6 is intact5 In damp locations, ma%e sure &ires and connectors

are &aterproof and approved for such locations5 o not

create a trippin6 ha@ard5

q Check 0oer cords and eGtensions —2lectrical cords should be

inspected re6ularly usin6 the follo&in6 procedure-

*5 <emove the cord from the electrical po&er source before

inspectin65

5 9a%e sure the 6roundin6 pron6 is present in the plu65

/5 9a%e sure the plu6 and receptacle are not dama6ed5

!5 7ipe the cord clean &ith a diluted deter6ent and e1amine for

cuts, brea%s, abrasions, and defects in the insulation5

'5 $oil or han6 the cord for stora6e5 o not use any other methods5

$oilin6 or han6in6 is the best &ay to avoid ti6ht %in%s, cuts, and

scrapes that can dama6e insulation or conductors5?ou should also test electrical cords re6ularly for 6round continuity

usin6 a continuity tester as follo&s-

*5 $onnect one lead of the tester to the 6round pron6 at one end

of the cord5

5 $onnect the second lead to the 6round &ire hole at the other

end of the cord5

/5 If the tester li6hts up or beeps (dependin6 on desi6n), the

cordGs 6round &ire is o%ay5 If not, the cord is dama6ed and

should not be used5

q Do not 0ull on cords —Al&ays disconnect a cord by the plu65



q se correct connectors —>se electrical plu6s and receptacles

that are ri6ht for your current and volta6e needs5 $onnectors are

desi6ned for specific currents and volta6es so that only matchin6 plu6s and receptacles &ill fit to6ether5 This safe6uard prevents a

piece of eDuipment, a cord, and a po&er source &ith different

volta6e and current reDuirements from bein6 plu66ed to6ether5

Standard confi6urations for plu6s and receptacles have beenestablished by the National 2lectric 9anufacturers Association

(N29A)5

Section Page B%

H&K&5DS S&, WO5 P5&*0I*,Sq se locking connectors —>se loc%in63type attachment plu6s,

receptacles, and other connectors to prevent them from becomin6

unplu66ed5

<e and maintain tool properly?our tools are at the heart of your craft5 Tools help you do your =ob

&ith a hi6h de6ree of Duality5 Tools can do somethin6 else, too5

They can cause in=ury or even death ?ou must use the ri6ht tools

for the =ob5 Proper maintenance of tools and other eDuipment is very

important5 InadeDuate maintenance can cause eDuipment to deteriorate,

creatin6 dan6erous conditions5 ?ou must ta%e care of your tools

so they can help you and not hurt you5

q Ins0ect tools before using the+ —$hec% for crac%ed casin6s,

dents, missin6 or bro%en parts, and contamination (oil, moisture,

dirt, corrosion)5 ama6ed tools must be removed from service and

properly ta66ed5 These tools should not be used until they are

repaired and tested5z Maintain tool and e:uipmentz Inpect your e:uipment before

you ue it

Page B> Section 9ocking#type attachment plug0hi cord ha beenpliced uing a 'ire nutSpliced cord are +erydangerou.

S&,02 MOD,9 S0&;, %/*ON05O99IN;q se the right tool correctly —>se tools correctly and for their

intended purposes5 0ollo& the safety instructions and operatin6

procedures recommended by the manufacturer5 7hen &or%in6 on

a circuit, use approved tools &ith insulated handles5 Ho&ever,

DO <O9 SE 9&ESE 9OO7S 9O *O$ O<

E<E$;I=ED CI$CI9S :7*:5S S&9 O??:<D DE.E<E$;I=E CI$CI9S BE?O$E

BE;I<<I<; *O$ O< 9&E!5

q -rotect your tools —:eep tools and cords a&ay from heat, oil,

and sharp ob=ects5 These ha@ards can dama6e insulation5 If a tool

or cord heats up, stop usin6 it <eport the condition to a supervisor

or instructor immediately5 If eDuipment has been repaired,

ma%e sure that it has been tested and certified as safe before

usin6 it5 Never carry a tool by the cord5 isconnect cords by



pullin6 the plu6—not the cord

q se double.insulated tools —Portable electrical tools are classified

by the number of insulation barriers bet&een the electricalconductors in the tool and the &or%er5 The N2$ permits the use

of portable tools only if they have been approved by

>nder&riterGs Eaboratories (>E Eisted)5 2Duipment that has t&o

insulation barriers and no e1posed metal parts is called doubleinsulated57hen used properly, double3insulated tools provide

reliable shoc% protection &ithout the need for a third 6roundz <e the right tool and e:uipmentz Do not 'ork on energi1ed circuit

Section Page B@

&n employee was climbing a metal ladder to hand an electric drill to the 7ourneyman installer on

a scaffold about D feet above him. #hen the victim reached the third rung of the ladder, hereceived an electrical shock that killed him. 5n investigation showedthat the grounding prong was missing from the e'tension cord attached tothe drill. 5lso, the cord%s green grounding wire was, at times, contacting theenergied black wire. 4ecause of this contact with the MhotM wire, the entirelength of the grounding wire and the drill%s frame became energied. &he drillwas not double"insulated.&o avoid deadly incidents like this one, take these precautionsI ake certain that approved L>C8%s or e$uipment grounding systems areused at construction sites.I se e$uipment that provides a permanent and continuous path to ground.

5ny fault current will be safely diverted along this path.I 8nspect electrical tools and e$uipment daily and remove damaged or defective e$uipment from use right away.

DonAt 'ork on energi1edcircuit like thi one.&l'ay follo' correct

lock#outLtag#out procedureH&K&5DS S&, WO5 P5&*0I*,S&ire5 Po&er tools &ith metal housin6s or only one layer of effective

insulation must have a third 6round &ire and three3pron6 plu65

q se +ulti0le safe 0ractices —<emember- A circuit may not be

&ired correctly5 7ires may contact other KhotL circuits5 Someone

else may do somethin6 to place you in dan6er5 Ta%e all possible

precautions5

Wear correct PP,OSHA reDuires that you be provided &ith personal protective eDuipment5

This eDuipment must meet OSHA reDuirements and be appropriate

for the parts of the body that need protection and the &or%

performed5 There are many types of PP2- rubber 6loves, insulatin6shoes and boots, face shields, safety 6lasses, hard hats, etc5 2ven if

la&s did not e1ist reDuirin6 the use of PP2, there &ould still be

every reason to use this eDuipment5 PP2 helps %eep you safe5 It is

the last line of defense bet&een you and the ha@ard5zWear and maintain PP,

Page BB Section



&22"year"old male carpenter was building the wooden framework of a laundry building. -e was using

portable power tools. /lectricity was supplied to the tools by a temporary service pole D0 feet away.&he service pole had not been inspected and was not in compliance. 8t was also not grounded. &hecarpenter plugged a homemade3 cord into the service pole and then plugged a "approved cord into the

homemade cord. -is power saw was plugged into the "approved cord.&he site was wet. -umidity was high and the carpenter was sweating. +eportedly, he was mildly shockedthroughout the morning and replaced the e'tension cord he was using in an effort to stop the shocks. 5t onepoint, as he was climbing down a makeshift ladder constructed from a floor truss, he shifted the power sawfrom his right hand to his left hand and was shocked. -e fell from the ladder into a puddle of water, still holdingthe saw. &he current had caused his hand to contract, and he was locked3 to the saw. 5 co"worker disconnected the power cord to the saw. C*+ was given, but the shock was fatal.

5ttention to these general safety principles could have prevented this death.? 5ny and all electrical e$uipment involved in a malfunction should be taken out of service immediately. &hecarpenter should have taken the saw out of service, not 7ust the e'tension cord. (5s it turns out, the sawwas the source of the shocks, not the cord.)? 5lthough the homemade e'tension cord does not seem to have contributed to this incident, it should nothave been used.? &he floor truss should not have been used as a ladder. >or climbing, use only approved ladders or other e$uipment designed specifically for climbing.

? <o not work in wet areas. &he water should have been removed from the floor as soon as it was found.-umidity and perspiration can also be haards. &ry to stay as dry as possible, be alert, and take action toprotect yourself when needed.? K-5 re$uires that all receptacles at construction sites that are not part of the permanent wiring haveL>C8%s.? 4e aware that shocks can cause you to lose your balance and fall, often resulting in more severe in7ury.

S&,02 MOD,9 S0&;, %/*ON05O99IN;q *ear safety glasses —7ear safety 6lasses to avoid eye in=ury5

q *ear 0ro0er clothing —7ear clothin6 that is neither floppy nor

too ti6ht5 Eoose clothin6 &ill catch on corners and rou6h surfaces5

$lothin6 that binds is uncomfortable and distractin65

q Contain and secure loose hair —7ear your hair in such a &ay

that it does not interfere &ith your &or% or safety5

q *ear 0ro0er foot 0rotection —7ear shoes or boots that have been approved for electrical &or%5 (Tennis shoes &ill not protect

you from electrical ha@ards5) If there are non3electrical ha@ards

present (nails on the floor, heavy ob=ects, etc5), use foot&ear that

is approved to protect a6ainst these ha@ards as &ell5

q *ear a hard hat —7ear a hard hat to protect your head from

bumps and fallin6 ob=ects5 Hard hats

must be &orn &ith the bill for&ard

to protect you properly5

q *ear hearing 0rotectors —7ear

hearin6 protectors in noisy areas to

prevent hearin6 loss5

q ?ollo directions —0ollo& themanufacturerGs directions for cleanin6

and maintainin6 PP25

q !ake an effort —Search out and

use any and all eDuipment that &ill

protect you from shoc%s and other

in=uries5z 0hink about 'hat you are doingz PP, i only effecti+e 'hen ued



correctly

Section Page BCWear afety glae to a+oid eye in-ury&rcing electrical burnthrough the +ictimAhoe and around the

rubber oleDonAt 'ear hardhat back'ard.

H&K&5DS S&, WO5 P5&*0I*,SPage B Section PP2 is the last line of defense a6ainst &or%place ha@ards5 OSHA defines PP2 as UeDuipment for the eyes, face, head, and e1tremities, protective clothin6, respiratory devices, protective shields and

barriers5U 9any OSHA re6ulations state that PP2 must meet criteria set by the American National

Standards Institute (ANSI)5

Head ProtectionOSHA reDuires that head protection

(hard hats) be &orn if there is a ris% of

head in=ury from electrical burns or fallin68flyin6ob=ects5

&renAt all hard hat the ame6 No5 ?ou must &ear the ri6ht hat for the =ob5 All hard

hats approved for electrical &or% made since *++#

are mar%ed U$lass 25U Hard hats made before *++#

are mar%ed U$lass C5U These mar%in6s &ill be on a

label inside the helmet or stamped into the helmetitself5 Ne&er hats may also be mar%ed U,ype -U or

U,ype .5U Type * hard hats protect you from impacts

on the top of your head5 Type hard hats protect

you from impacts on the top and sides of your head5

Ho' do I 'ear and care for myhard hat6Al&ays &ear your hat &ith the bill for&ard5 (Hats

are tested in this position5) If you &ear a hat differently,

you may not be fully protected5 The hat

should fit snu6ly &ithout bein6 too ti6ht5 ?ou shouldclean and inspect your hard hat

re6ularly accordin6 to the manufacturerGs

instructions5 $hec%

the hat for crac%s, dents, frayedstraps, and dullin6 of the

finish5 These conditions canreduce protection5 >se only

mild soap and &ater for cleanin65

Heavy3duty cleaners and

other chemicals can dama6e

the hat5H,&D P5O0,*0ION

*la ,3 0ype $ hard hat *la = hard hatDonAt 'ear another hat



under your hard hat.

PP, act Sheet/0he 5ight ,:uipment/Head toSection Page BGo not UstoreU anythin6 (6loves, &allet, etc5) in thetop of your hard hat &hile you are &earin6 it5 The

space bet&een the inside harness and the top of the

hard hat must remain open to protect you5 o not

put stic%ers on your hat (the 6lue can &ea%en thehelmet) and %eep it out of direct sunli6ht5 If you

&ant to e1press your personality, hard hats come in

many colors and can be imprinted &ith custom

desi6ns by the manufacturer5 Some hats are available

in a co&boy hat desi6n or &ith sports lo6os5

<e your head and protect your head.Ne+er 7tore8 anything in the topof your hard hat 'hile you are'earing it*la = hard hat in a co'boyhat deigneep your hard hat out of direct unlight 'hen you are not 'earing it.

0oeoot Protection7or%ers must &ear protective foot&ear

&hen there is a ris% of foot in=ury from

sharp items or fallin68rollin6 ob=ects—

or &hen electrical ha@ards are present5 As

&ith hard hats, al&ays follo& the manufacturerGs

instructions for cleanin6 and maintenance

of foot&ear5 <emember that cuts, holes, &orn

soles, and other dama6e can reduce protection5

Ho' do I chooe theright foot'ear6The foot&ear must be ANSI approved5 ANSI

approval codes are usually printed inside the ton6ue

of the boot or shoe5 0oot&ear &ill be mar%ed U E/ U

if it is approved for electrical &or%5 (The ANSI

approval stamp alone does not necessarilymean the foot&ear offers protection

from electrical ha@ards5) Note that

foot&ear made of leather must be %ept

dry to protect you from electrical ha@ards,

even if it is mar%ed U E/ 5U

What about non#electricalha1ard6



All ANSI approved foot&ear has a protective toe

and offers impact and compression protection5 Cut

the type and amount of protection is not al&ays the

same5 ifferent foot&ear protects you in different

&ays5 $hec% the productGs labelin6 or consult themanufacturer to ma%e sure the foot&ear &ill

protect you from the ha@ards you face5OO0 P5O0,*0ION

DonAt take rik becaue you are 'earing PP,PP, i the lat line of defene againt in-ury.* P *ompression ratingQ&his code is more comple' thanthe others. -ere is how to read it!0 P ,000 pounds?D0 P ,1D0?C@ P 2,D00 (in this e'ample)RM0 P Metatarsal (top of the foot)protection rating (C@ foot pounds inthis e'amplecan also be !0 or D0)

&NSI K>$ P 5:8 footwear protection standardP0 P Protective 0oe sectionof the standardG$ P year of the standard(in this e'ample HH)M P Male footwear ( P emale footwear)I P Impact rating(C@ foot pounds inthis e'amplecanalso be !0 or D0)

Page C" Section

PP, act Sheet (continued)S&,02 MOD,9 S0&;, %/*ON05O99IN;

Summary of Section $ontrol ha@ards throu6h safe &or% practices5

Plan your &or% and plan for safety5

Avoid &et &or%in6 conditions and other dan6ers5Avoid overhead po&erlines5

>se proper &irin6 and connectors5

>se and maintain tools properly5

7ear correct PP25

Section Page C$

H&K&5DS S&, WO5 P5&*0I*,SPage C!

;loary of 0erma+0acity

ma1imum amount of current a &ire can carry safely &ithout overheatin6

a+0erage

stren6th of an electrical current, measured in amperes

a+0ere a+0



unit used to measure current

arc.blast

e1plosive release of molten material from eDuipment caused by

hi6h3ampera6e arcs

arcing

luminous electrical dischar6e (bri6ht, electrical spar%in6) throu6h

the air that occurs &hen hi6h volta6es e1ist across a 6ap bet&eenconductors

:*;

:merican *ire ;au6e—measure of &ire si@e

bonding

=oinin6 electrical parts to assure a conductive path

bonding 6u+0er

conductor used to connect parts to be bonded

circuit

complete path for the flo& of current

circuit breaker

overcurrent protection device that automatically shuts off the current

in a circuit if an overload occursconductor

material in &hich an electrical current moves easily

C-$

cardio0ulmonary resuscitation—emer6ency procedure that involves6ivin6 artificial breathin6 and heart massa6e to someone &ho is not

breathin6 or does not have a pulse (reDuires special trainin6)

current

movement of electrical char6e

de.energi%e

shuttin6 off the ener6y sources to circuits and eDuipment and

depletin6 any stored ener6y

double.insulatedeDuipment &ith t&o insulation barriers and no e1posed metal parts

energi%ed live/ hot

similar terms meanin6 that a volta6e is present that can cause a

current, so there is a possibility of 6ettin6 shoc%ed

fault current

any current that is not in its intended path

Page C%

;loary of 0erm (continued)fiGed iring

permanent &irin6 installed in homes and other buildin6s

fleGible iringcables &ith insulated and stranded &ire that bends easily

fuse

overcurrent protection device that has an internal part that melts and

shuts off the current in a circuit if there is an overload

;?CI

ground f ault circuit interrupter—a device that detects current

lea%a6e from a circuit to 6round and shuts the current off

ground



physical electrical connection to the earth

ground fault

loss of current from a circuit to a 6round connection

ground 0otential

volta6e a 6rounded part should have . volts relative to 6round

guarding

coverin6 or barrier that separates you from live electrical partsinsulation

material that does not conduct electricity easily

leakage current

current that does not return throu6h the intended path, but instead

Ulea%sU to 6round

lock.out

applyin6 a physical loc% to the ener6y sources of circuits and eDuipment

after they have been shut off and de3ener6i@ed

+illia+0ere +illia+0 or +:

*8*,... of an ampere

<EC

<ational Electrical Code—comprehensive listin6 of practices to protect&or%ers and eDuipment from electrical ha@ards such as fire and

electrocution

neutral

at 6round potential (. volts) because of a connection to 6round

oh+

unit of measurement for electrical resistance

OS&:

Occupational Safety and &ealth :dministration—0ederal a6ency in

the >5S5 epartment of Eabor that establishes and enforces &or%place

safety and health re6ulations

Page C>

;loary of 0erm (continued)overcurrent 0rotection device

device that prevents too much current in a circuit

overload

too much current in a circuit

0oer

amount of ener6y used each second, measured in &atts

--E

0ersonal 0rotective eDuipment (eye protection, hard hat, special

clothin6, etc5)

Aualified 0erson

someone &ho has received mandated trainin6 on the ha@ards and onthe construction and operation of eDuipment involved in a tas%

resistance

materialGs ability to decrease or stop electrical current

risk

chance that in=ury or death &ill occur

shocking current

electrical current that passes throu6h a part of the body

short



lo&3resistance path bet&een a live &ire and the 6round, or bet&een

&ires at different volta6es (called a fault if the current is unintended)

tag.out

applyin6 a ta6 that alerts &or%ers that circuits and eDuipment have

been loc%ed out

tri0

automatic openin6 (turnin6 off) of a circuit by a F0$I or circuit brea%er

voltage

measure of electrical force

ire gauge

&ire si@e or diameter (technically, the cross3sectional area)

,ndnote*5 $astillo N V*++'W5 NIOSH alert- preventin6 death and in=uries of adolescent

&or%ers5 $incinnati, OH- >5S5 epartment of Health and Human Services,Public Health Service, $enters for isease $ontrol and Prevention, National

Institute for Occupational Safety and Health, HHS (NIOSH) Publication

No5 +'3*'55 Eee <E V*+#/W5 2lectrical safety in industrial plants5 Am Soc Safety 2n6 ;

*(+)-/"3!5/5 OE V*++#W5 $ontrollin6 electrical ha@ards5 7ashin6ton, $- >5S5 epartment

of Eabor, Occupational Safety and Health Administration5

&ppendi4OS&: StandardsOSHA occupational safety and health standards for Feneral

Industry are located in the "ode of #ederal $egulations ($0<),Title +, Part *+*. (abbreviated as + $0< *+*.)5 Standards

for $onstruction are located in Part *+" (abbreviated as +$0< *+")5 The full te1t of these standards is available on

OSHAXs 7eb site- &&&5osha56ov5

OSHA standards related to electrical safety for FeneralIndustry are listed belo&-

Sub0art S#ElectricalF2N2<AE

*+*.5/.* 3 Introduction2SIFN SA02T? STANA<S 0O< 2E2$T<I$AE S?ST29S

*+*.5/. 2lectric utili@ation systems

*+*.5/./ Feneral reDuirements

*+*.5/.! 7irin6 desi6n and protection*+*.5/.' 7irin6 methods, components, and eDuipment for

6eneral use*+*.5/." Specific purpose eDuipment and installations

*+*.5/.# Ha@ardous (classified) locations

*+*.5/. Special systems

SA02T?3<2EAT2 7O<: P<A$TI$2S

*+*.5//* Scope

*+*.5// Trainin6*+*.5/// Selection and use of &or% practices

*+*.5//! >se of eDuipment*+*.5//' Safe6uards for personnel protection

Sub0art H#;eneral Environ+ent Controls*+*.5*!# The control of ha@ardous ener6y (loc%3out8ta63out)

*+*.5*!# Appendi1 A—Typical minimal loc%3out procedures

Sub0art $#S0ecial Industries*+*.5" Telecommunications



*+*.5"+ 2lectric po&er 6eneration, transmission, and distributionOSHA standards related to electrical safety for $onstruction are

listed belo&-

Sub0art #ElectricalF2N2<AE

*+"5!.. IntroductionINSTAEEATION SA02T? <2>I<292NTS

*+"5!. Applicability*+"5!./ Feneral reDuirements

*+"5!.! 7irin6 desi6n and protection

*+"5!.' 7irin6 methods, components, and eDuipment for 6eneral use

*+"5!." Specific purpose eDuipment and installations

*+"5!.# Ha@ardous (classified) locations*+"5!. Special systems

SA02T?3<2EAT2 7O<: P<A$TI$2S

*+"5!*" Feneral reDuirements

*+"5!*# Eoc%3out and ta66in6 circuits

SA02T?3<2EAT2 9AINT2NAN$2 AN 2NQI<ON92NTAE

$ONSI2<ATIONS

*+"5!/* 9aintenance of eDuipment*+"5!/ 2nvironmental deterioration of eDuipmentSA02T? <2>I<292NTS 0O< SP2$IAE 2>IP92NT

*+"5!!* Catteries and battery char6in620INITIONS

*+"5!!+ efinitions applicable to this subpart

Sub0art 8#-oer 9rans+ission and

Distribution*+"5+'. Feneral reDuirements*+"5+'* Tools and protective eDuipment

*+"5+' 9echanical eDuipment*+"5+'/ 9aterial handlin6

*+"5+'! Froundin6 for protection of employees

*+"5+'' Overhead lines*+"5+'" >nder6round lines

*+"5+'# $onstruction in ener6i@ed substations

*+"5+' 21ternal load helicopters*+"5+'+ EinemanXs body belts, safety straps, and lanyards

*+"5+". efinitions applicable to this subpart

Page C@Page CB

:aluminum &ire ha@ard !

amp "

ampacity !

ampere "arc3blast *

arc3fault circuit brea%er !"

arcin6 *, +

arthritis /.A7F /+

B bondin6 !+

bondin6 =umper '. burns, arc *, *'

burns, electrical ", *., *, *'

burns, thermal contact *, *'



Ccable, !.v !

cardiopulmonary resuscitation 1(

carpal tunnel syndrome /*circuit

circuit brea%er +, /!, "

circuit brea%er, and lea%a6e current clearance distance "clues of electrical ha@ards /!

clues,

blo&n fuses /!

tripped circuit brea%ers /!tripped F0$I /'

&arm e1tension cord /!

&arm =unction bo1 /'

&arm tools and &ire /!&orn insulation /'

$ode of 0ederal <e6ulations #'

concussion *

conductor /controllin6 ha@ards *+, *, 3', "4

$P< (see cardiopulmonary

resuscitation)$0< (see $ode of 0ederal <e6ulations)

current,

calculatin6 !

current effects on body #

path throu6h body , +, *.

current lea%a6e !#

cuts /*

D

de3ener6i@in6 circuits ''Eelectrical ha@ards,aluminum &ire !

dama6ed hand tool /*, /!

dama6ed tool +defective insulation "

e1posed electrical parts !

improper 6roundin6 #

inadeDuate &irin6 !overhead po&erline '

overload

&et conditions +

electrical shoc%,amount ", **

current density +

duration ", #, **

path , +, *., **receivin6

electrical shoc%—&hat to do for *"

electrocution, deaths *, #, *.

ener6i@ed evaluatin6 ha@ards *+, *, 34



evaluatin6 ris% /!

e1tension cord !, /!, 42, !", '3

?falls '"fault #

fault, lo& current !#

fire e1tin6uisher, types *!fires, electrical *!, !, , +fires—&hat to do *!

fi1ed &irin6 !.

fle1ible &irin6 !*

foot protection (

free@in6 "

fuse +, /!, '*

;F0$I

(see 6round fault circuit interrupter)

6round

6round connection !#

6round fault 6round fault circuit interrupter

, /!, 4,, "*

6round potential #6roundin6 #, , 4'

6roundin6 path !#

6uardin6 43

&hard hat ',

ha@ards (also see electrical ha@ards),

chemical /.

control (see controllin6 ha@ards)fallin6 ob=ects /

falls /inadeDuate &irin6 !

liftin6 /overhead &or% /.

particles /

ha@ardous environments '*

Iimpedance

insulation ", 44

insulation dama6e !'isolation 43

H

=e&elry '" =umper, bondin6 !+

%ill s&itches *#

7ladder safety ",

lea%a6e current

live

loc%3out8ta63out /#, 3,



loc%3out8ta63out chec%list 3,

lo& bac% pain /*

IND,Page CC

!mA "

milliamp "milliampere "

< National 2lectrical $ode *' National 2lectrical Safety $ode *+

N2$ (see National 2lectrical $ode)

N29A "/

N2S$ (see National 2lectricalSafety $ode

nonconductive material

OOccupational Safety and Health

Administration *'ohm

OSHA (see Occupational Safety and

Health Administration)overhead po&er lines ', '1

overload

- personal protective eDuipment

/*, '', ',, ,

perspiration /.

plu6s, three3pron6 " po&er !

po&er ratin6 !

PP2(see personal protective eDuipment)

$ reco6ni@in6 ha@ards *, *, 22

resistance

resistance, effect on current respiratory paralysis "

ris% /!

ris% evaluation /!

Ssafe &or% environment *+, 3'

safe &or% practices *+, "4

safety model, overvie& *shoc% (see electrical shoc%)

shoc%in6 current "

short /!

9tendinitis /.

tools '4

tools, double3insulated "'

8



ventricular fibrillation "

volta6e,

hi6h #, *

lo& "volta6e

*

&et conditions +, '1&ire 6au6e !&ire si@e !

IND,YP5 Carber8$9SP—+

<ichard $arlson—/a, "b, '#, "'aY$orbis Ima6es—"

Y95 2n6lish8$9SP—*.

Thaddeus 75 0o&ler—/!, !"a, !#a, '*$at Foldber6—cover, ', ., 'a, "a, #, /., /*,

/a, /#a, /ab, !/c, !+, '., '', '", 'b, '+a,"!b, "'b, "#ac, "abc, "+ac, #.

:aren :5 9iles—*!bc, *, *+, /b, !, 'b,

/#b, /+, !, 'c, "*, ", "!a, "+b

YPhotoisc—*, , /, , *!a, ab, +, /b, !.,!/a, !!, !"b, !#b, 'a, '+bc, ""

YPhotouest—'c, !/b<5:57ri6ht, 955—&&&5emedicine5com

*, "#b

Photo and ;raphic *redit

9o receive infor+ation about occu0ational safety and health 0roble+s/ call <IOS& at

1.,.3".<IOS& 1.,.3"'.4'(4

?aG nu+ber) "13 "33.,"(3

E.+ail) 0ubstaftJcdcgov

or visit the <IOS& *eb site at cdcgov@nioshDHHS (NIOSH) Publication No !""!#$!%Deli+ering on the NationA promieSafety and health at 'ork for all peoplethrough reearch and pre+ention

electrical saftey

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