Electrical Awareness

8/13/2019 Electrical Awareness

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Electrical Awareness


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Session Objectives You will be able to:

Understand the hazards of electricity

Identify and avoid common electricalhazards

Follow safe work practices around electricalequipment


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Electrical Hazards Contact with overhead and buried power

lines

Contact with damaged electrical equipment

Improper wiring

Overloading

Unsafe work practices


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Electrical Injuries Cardiac arrest and respiratory failure from

electrical shock or electrocution

Muscle, nerve, and tissue destruction fromcurrent passing through the body

Burns from arc flash and arc blast

Thermal burns from contact with source

Secondary injuries


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How Electrical Shock

Occurs Shockelectrical

energy contacts yourbody

Contact two wires orcomponents atdifferent voltages

Contact an energized

wire or component anda grounded object


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Severity of Electrical ShockSeverity depends on:

Amount of electrical currenthigher is more

dangerous Durationlonger is more dangerous

Path through the bodythrough the heartmost dangerous


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Effects of Electrical

Current on the BodyCURRENT

1 SECOND

BODYS RESPONSE

0.5

3 mAmpFaint, tingling sensation

3-5 mAmp Slight shock, minor muscle contraction, can control muscles

6-30 mAmp Painful shock, muscle contractions severe, cannot control muscles

5-150 mAmpExtremely painful shock, respiratory arrest, severe muscle

contractions, death may occur

14 Amp Ventricular fibrillation, nerve damage, death is likely

10 Amp Cardiac arrest, severe burns, death is probable

15 Amp Lowest overcurrent protection of common fuse or circuit breaker


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Injuries from Electrical

Shock Electrocution

Injuries:

Blood vessels, nerves,

organs, and burns

Secondary injuries

Falls

Trauma


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Arc Flash and Arc BlastArc Flashelectricity

flows through the air

Temperatures as high as

35,000 degrees,vaporizing metal

Severe skin burns

Arc Blastpressure

wave from an arc flash Severe injuries from blast

Facility and equipment

damage

Image Credit: OSHA


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Electrical Burns Burns are a common

shock-related injury

Electricity generatesheat in the body 2nd and 3rd degree

Some severe burns

appear minor on the

outside

Thermal burns from hotsurfaces and fires


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Electrical Hazards

Any Questions?Any questions about the hazards and

injuries of electricity in the workplace?


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Emergency Response

and First Aid for ShockIf a person is shocked:

Do not touch theperson during theshock event

Shut off electricalcurrent

Call for help:

Telephone: 9-911

Radio: Channel 2


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Stay Away from Power

Lines Overhead power lines

Stay at least 10 feet away

Keep all equipment (aerial lifts, cranes, scaffolds,

ladders, etc.) at least 10 feet away

Add 5 feet for every 150 kV, over 50 kV


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Stay Away from Power

Lines Buried power lines

Dont dig until verified that buried lines and other

utilities are not in the area. !!You must have avalid excavation permit for any excavation

over 4 deep (includes rebar posts)!!


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Report and Dont Use

Damaged EquipmentStop using and report:

Broken or missingcovers

Damaged tools

cords

equipment

Only qualifiedpersons are allowedto work on, or makerepairs to, electricalequipment or wiring.


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Ensure Electrical

Equipment Is Grounded If no safe path to ground, exposed parts can

become energized

Electric power-operated tools andequipment must be grounded or double-insulated

Path to ground must be continuous


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Ground Fault Circuit

Interrupter (GFCI) GFCIs detect current

between the two circuitwires

Trip at about 5 mAmp

Can get a shock beforeit trips

If it keeps tripping there

is a problem Need to be periodically

tested


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Follow Lockout/Tagout

Procedures Devices that prevent

access to hazardousenergy

Lockout ensuresequipment isntaccidentally restarted

Tagout used where

lockout not feasible Follow Lockout/Tagout

program procedures


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Follow Safe Work Practices Only qualified persons may work on or

near exposed electrical equipment and

wiring Dont wear conductive apparel

Work area must be illuminated

Dont allow conductive liquids near electrical

work or equipment Do not defeat electrical interlocks

Use nonconductive ladders


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Use Portable Electrical

Equipment Safely Before using

Inspect for damage

Check cord andground

Use safely

Dont lift by cord

Dry hands when

plugging andunplugging

Use GFCI in ALLlocations, esp. wetareas


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Circuit Protective Devices Circuit breakers and fuses are designed to

trip if overloaded

Dont reset unless authorized to do so Contact a qualified person to investigate


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Stay Away from Electrical

Work Areas Electrical work areas

need to be isolated

Alerting Techniques

Safety Signs and

Tags

Barricades

Attendants


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Follow the Electrical

Safety Program Written procedure includes:

Responsibilities

Procedures Safe work practices

Personal protective equipment

Only qualified personnel may work on or

near exposed energized equipment!


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Safety Practices

Any Questions?Any questions about:

First aid?

Electrical equipment? Electrical circuits?

Lockout/Tagout?

Safe work practices? The electrical safety program?


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Key Things to Remember Exposure to electricity can cause

electrocution, shock, electric and thermalburns, arc flash and arc blast burns, and

secondary injuries Watch carefully for electrical hazards

Follow safe work practices, includingemergency response procedures

Follow the electrical safety program !! Only qualified persons may work on, or

make repairs to, electrical equipment orwiring !!


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Remember if you have

questions, before you

proceed, STOPand

ask!

Electrical Awareness

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