Basic Electrical Safety Module 1

7/29/2019 Basic Electrical Safety Module 1

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Electrical Hazards AwarenessBriefing

Basic Electrical Safety Hazard Awareness for

Non-Electrical Personnel

Module 1


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Purpose The purpose worker safety

Raising your awareness of electrical hazards

Instructing you on how to recognize electrical hazards

Providing ways to eliminate, remove and preventelectrical hazards in the workplace

Emphasizing the extreme importance of observing all

electrical safety requirements and practices

Instructing you on what to do during an electrical

accident


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Introduction

An average of one worker is electrocuted on the job everyday

An average of one person is electrocuted in the homeevery 36 hours

Electrical incidents are far more likely to be fatal thanother types

There are four main types of electrical injuries:

Electrocution (death due to electrical shock)

Electrical shock

Burns

Falls


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Electrical Shock

Received when current passes

through the body

Severity of the shock depends on:

Path of current through the body

Amount of current flowing

through the body

Length of time the body is in the

circuit


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Dangers of Electrical Shock

Currents greater than 75 mA*can cause ventricular fibrillation(rapid, ineffective heartbeat)

Will cause death in a few

minutes unless a defibrillator isused

75 mA is not much current asmall power drill uses 30 times

as much

* mA = milliampere = 1/1,000 of an ampere

Defibrillator in use


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How is an electrical shock received?

When two wires have different potential differences(voltages), current will flow if they are connectedtogether

In most household wiring, the black wires are at110 volts relative to ground

The white wires are at zero volts because theyare connected to ground

If you come into contact with an energized (live)

black wire, and you are also in contact with thewhite grounded wire, current will pass through yourbody and YOU WILL RECEIVE A SHOCK


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How is an electrical shock received?(contd)

If you are in contact with an energized wire or any

energized electrical component, and also with any

grounded object, YOU WILL RECEIVE A SHOCK

You can even receive a shock when you are not in

contact with a ground

If you contact both wires of a 240-volt cable,

YOU WILL RECEIVE A SHOCK and possiblybe electrocuted


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Low Voltage Does Not Mean Low

Hazard A small amount of electrical current can cause injury,

even death

The current from a 7.5-watt, 120-volt lamp, passing

across the chest, is enough to cause fatal

electrocution

Deaths from 120 volts represent about 12 percent ofall electrocutions


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Electrical Burns

Most common shock-related,

nonfatal injury

Occurs when you touch

electrical wiring or equipmentthat is improperly used or

maintained

Typically occurs on the hands

Very serious injury that needs

immediate attention


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Recognize the HazardsHave you seen areas like these?

Both are NEC violations and present a safety hazard, based on inaccessible circuit control devices

Do not block the working space around electrical equipment (600 volts, nominal, or less). This space provides

and maintains sufficient access and working space to permit ready and safe operation and maintenance of such

equipment


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Recognize the HazardsWhat do you do if you see these situations?

Call a timeout and inform your supervisor

Do not remove or open receptacle covers, switch plates, or covers of electrical equipment

unless qualified and authorized


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Recognize the Hazard

Assume all exposed wiring

is energized until proven

otherwise. STOP, protectthe area and contact

supervision if you

encounter this situation

Potentially

energized

exposed wire

with status

unknown


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Tripping and Abrasion Hazards Dont cause tripping

hazards or create

pinch points for

cords

If you must run a

cord temporarily

across the floor,

protect your co-workers by

covering the cord

appropriately

Not OK OK


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Recognize the HazardsRemove from service damaged or frayed cords

Report electrical equipment damage to your supervisor

Stay clear ofbare, exposed

wiring and

REPORT IT!

Visually inspect electrical equipment

before each use for damage and/or

external defects such as loose,

missing or deformed parts, pinchedor crushed outer jackets or insulation.

This type of external damage may

indicate internal damage to the

equipment.

Electrical cords that are worn or

damaged must be replaced without

delay. Before cleaning electrical equipment,

turn it off and unplug it.


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Recognize the HazardCabinets, Boxes, and Fittings

Junction boxes, pull boxesand fittings must haveapproved covers in place

Unused openings in cabinets,boxes and fittings must beclosed (no missing knockouts)

Photo shows violations ofthese two requirements

Report this situation tomanagement


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Recognize the Hazards

Never daisy chain multi-outlet strips (plugging into each other)


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Observe all barricades,

postings, and warning

signs regarding dangerous

voltages

Do not enter or approach

electrical work areas unless

specifically authorized and

qualified.


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Recognize the Hazards

Not permitted and should be taken out of service!

Electrical boxes with knockouts are designed to

be installed in or on walls, not used as multi-

outlet extension cords.


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Grounding Path The path to ground from

circuits, equipment, andenclosures must be permanentand continuous

Violation shown here is anextension cord with a missinggrounding prong

Do not make alterations topolarized blades or ground pinto make plug fit into non-polarized or non-groundedoutlet


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Recognize the Hazards Electrical hazards may exist

overhead indoors

Crane power rails are an

example

Electrical hazards may alsoexist overhead outdoors

Most lines are bare and

higher voltage than the

normal insulated wiring

Contact is not required to

initiate an arc or cause shock

and burn injuries

Maintain safe approach

distances when working near

energized overhead lines

Stay at least 10 feet away from overhead lines


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Electrical equipment and

wiring must not be exposed

to physical damage

Picture shown here isphysical damage to conduit

Stay away from damaged

equipment and report

equipment damage tosupervision


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Treat it as it is

designed to be

treated Pull the plug, not the

cord

Handle portable electrical equipment carefully, in accordance with manufacturers

instructions, and in a manner that will not cause damage


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Clues that Electrical Hazards

May Exist Tripped circuit breakers or blown fuses

Hot to the touch on tools, wires, cords, connections, or junction

boxes

Dim and flickering lights Sizzles and buzzes-unusual sounds from electrical system

Odor of hot insulation

Mild tingle from contact with case or equipment

GFCI that shuts off a circuit

Worn or frayed insulation around wire or connection

Burn marks or discoloration on receptacle plates or plug prongs


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Ground-Fault Circuit Interrupter

Always use a GFCI receptacle or circuit for cordconnected tools and equipment used outdoors ornear water

This device protects you from electrocution

The GFCI detects a difference in current betweenthe black and white circuit wires

(This could happen when electrical equipment isnot working correctly, causing current leakage known as a ground fault.)

Perform the test function on the GFCI todetermine if it is functioning properly by pushing

the button to verify it shuts off Repeated resetting not allowed. Contact local

E&I to troubleshoot if GFCI continues to trip.


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Prohibited Uses of Flexible CordsExamples

Substitute for

fixed wiring

Run through walls,

ceilings, floors,

doors, or windows

Concealed behind

or attached to

building surfaces


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Safe Practices

Cord Control Do not fasten electrical cords to surfaces with staples, nails,

wire, or any other method that might damage the cord

Extension cords

Place them in appropriate locations Understand they are for temporary use only

Tool cords

Keep track of them, to assure they do not become

damaged

Do not plug or unplug electrical cords with wet hands or

while standing in water


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Safe Practices

Cord Control Cont. Do not use portable electrical equipment or extension

cords in wet or damp locations without a ground fault

circuit interrupter (GFCI) ahead of the plug connection

GFCIs are also required for temporary power applications

in wet or damp locations, including extension cords

Remove loads from an appliance or extension cord before

unplugging it

If a plug wont stay placed snugly or fits loosely in a

receptacle, dont use it; call local E&I to replace it


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Safe Practices

Resetting Breakers When circuit breakers and fuses trip, dont reset or

replace them!

Only qualified and authorized personnel are allowed

to reset breakers and replace fuses

Contact qualified personnel to determine the cause oftrips


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Safe Practices

Conductive Apparel Dont wear loose

conductive apparel,

(such as rings,

watch bands,bracelets,

necklaces, etc.)

when plugging in

electrical cords

Burn

from arc

Charm

contacted

plug

Charm

contacted plug

here


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Safe Practices

Wall Penetrations When penetrating walls to hang pictures, bulletin boards,

signs, understand and follow site requirements to ensure that

concealed electrical wiring, conduit or piping will not be

contacted

A non-obtrusive survey (e.g., Ground Penetrating Radar,

proximity detection device) may be required, along with a

review of applicable drawings, to ensure that the electrical

system is not penetrated or contacted


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Safe Practices

Equipment Applications Consumer electrical equipment or

appliances should be tested andlabeled by a recognized testinglaboratory. (Look for the UL, CSA,ETL or MET Label)

Always read and follow themanufacturers instructions carefully.Be sure that the equipment or tool israted for the environment (wet, damp,etc.)

Plug portable space heaters directlyinto outlet: Do not use extension cord.Use a circuit with as little else on it aspossible since space heaters take alot of power.


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Safe Practices

Qualifications Do not remove/replace receptacle covers, switch

plates, or covers of electrical equipment that may

contain energized conductors without electrical

qualifications and authorization

Only qualified electrical workers may perform

activities such as electrical probing, measuring and

testing electrical energized components (such as

performing an absence of voltage test)


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Electrical Emergencies

Do you know what dangers could be encountered?

Attempts to rescue an accident victim may pose as

great a hazard for the rescuer as it does for the

victim

A victim of an electrical accident is often unable to

move or release the electrical conductor, because of

muscle clamping

Caution should be a primary consideration duringany electrical accident or emergency


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Do you know the proper actions to take if you see someone receiving ashock or locked onto an energized electrical line?

Approaching the accident:

Never rush into an accident situation-Assess your own safety

Call 911 as soon as possible Unplug portable electrical equipment to remove power (1st choice)

Open a disconnecting device or circuit breaker to de-energize fixedelectrical equipment

Use a dry wood broom, leather belt, plastic rope, or somethingsimilar that is non-conductive such as wood or plastic cane with

hook on the end to free the person from the energy source


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Downed Power Lines Do you know the proper actions to take?

Approaching the accident:

Move away from downed power line

Shuffle away with small steps keeping feet together If you see someone in direct contact with line, do not

touch person

Call 911 as soon as possible

Do not attempt to move downed power line

Get the aid of trained electrical personnel if possible If you are in your car and it is it contact with the downed

line, stay in car. Honk horn for help and tell others to stayaway from your vehicle


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What Now?

Inspect your work areas

Existing unsafe conditions

- Bare wires

- Open enclosures containing exposed wires

- Loose or missing covers or fasteners

- Use good electrical safe practices

-

No daisy-chaining- No overloading outlets

- Pull on plug, not cord


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What Now?

What do I do if I identify a hazardous condition?

When unsafe electrical conditions are found, correct

them if possible, or take steps to warn other

employees

Report unsafe electrical conditions verbally and/or in

writing to supervision so corrective actions can be

taken immediately

Barricade the area, if an immediate hazard existsNotify supervision for correction and documentation


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For More Information

Contact:

Your Site Electrical Safety Officer, or

Your Safety Engineer

WEB Sites

See DOE Electrical Safety Campaign at

www.eh.doe.gov/paa/electrical

See Electrical Safety Foundation International at

www.electrical-safety.org

Basic Electrical Safety Module 1

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Transcript of Basic Electrical Safety Module 1