69cfbasicelec.ppt

7/27/2019 69cfbasicelec.ppt

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Health& Safety & Fire Department

Phone : safety-2008, Fire -2000,

OHC- 2111, Security - 2060

Basic Electrical Safety


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Course not designed to teach you

to work on electrical equipment.

You will not be qualified to work on

electrical equipment.

If you spot problems with electrical

equipment you should report it to

your supervisor.

Basic Electrical Safety

Electri city is a form of energy, which is in visible, but

can be felt by its effects. Types of electr icity


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Be familiar with the fundamental concepts

of electricity.

Be familiar with the effects of electricityon the human body.

Be able to recognize common electrical

hazards.

Objectives


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Be familiar with electrical protective

devices.

Objectives


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Comply with applicable regulations

Reduce injuries Reduce liability

Reduce operating costs

Provide a safe work environment

Why be concerned

about electrical safety?


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Average of 4,000 non-disabling and 3,600 disablingelectrical contact injuries annually.

One person is electrocuted in the workplace everyday.

Electrocutions were the fourth leading cause oftraumatic occupational fatalities.

Over 2,000 workers are sent to burn centers eachyear with electrical burns.

Electrical Safety Statistics


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Safety Triangle


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Have You Ever Been Shocked?

THE BASICS

Fundamentals of Electrical Hazards


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Human body is a conductor when

the l ive wire touches the body

current completes its path through

body & earth. The muscular

functions wil l get effect due to

current action on the nervoussystem.



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Effect of current at various value

0-8 ma - perceptible & not pain full.

9-15 ma - pain full but muscular in control.

15-20 ma - pain full shock but muscular in control.20-50 ma - breathing difficulty.

50-100 ma - instant death.Over 4 amps

heart paralysis; severe burns. Usually caused by >600 volts



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Hazards of Electricity Electrocution/Shock/Burns/Death/Arc flash/Fire

ignition

Minimum distance from overhead lines 10 ft.

Inspect all electrical tools and equipment

Frayed, cut, broken wiresgrounding prong missing

Improper use of cube taps

improperly applied or missing strain relief



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Normal Condition

Maint. Work


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Abnormal Condition

Maint. Work


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Circuit Breakers

Provided to protect EQUIPMENT not people

Do not reset breakers with a line voltage higher than 120V and only

reset if you know why it tripped

GFCIs

- Provided to protect people

- Trip range 4-6ma- Monthly test

Electrical Protection


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Distance

If you sense the presence of an electrical

hazard or exposed conductors that may beenergized, keep your distance and STAY

AWAY

Electrical Protection


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Terminology


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Electrical Grounding


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Fundamentals of Electrical

Hazards

Voltage

electrical pressure (water pressure) Amperage

electrical flow rate (gallons/min)

Impedance restriction to electrical flow (pipe friction)


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Circuit

path of flow of electricity

Circuit Element

objects which are part of a circuit and

through which current flows.

Fault

current flow through an unintended path.


Hazards


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What is Grounding?

Protection from electric shock

normally a secondary protection measure

A ground is a conductive connection

between electrical circuit or equipment and

earth or ground plane

creates a low resistance to the earth.


Hazards


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Electricity isnt live until current flows

Electrical current wont flow until there is a

complete loop, out from and back to the

power source.

Basic Rules of Electrical Action


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Time

Electrocution Prevention

GFCI

Preventing Accidental Electrical Contact


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The important Dos

Only qualified persons should undertake electric

repairs. Treat all circuits as live unless ensured after

testing dead.

Ensure easy access to put off the power supply.

Dos and Don'ts


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The important Dos

While using any portable electrical equipment,

ensure that it is properly earthed, there is noleakage of current through the body of theequipment.

Place rubber mats where necessary.

Use protective, while working on electricalinstallations such as rubber gloves, shoes andinsulated tools.

Dos and Don'ts


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The important don'ts

Do not have any unsafe temporary connections, nakedjoints/wirings.

Do not just operate any switch unless you know theconsequences.

Do not overload on electrical point.

Do not use water for extinguishing electrical fire.

Do not crowd things near the electrical mains/switchboards.

Do not work on live circuits, even the job is very small.

Dos and Don'ts


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Employees should know the location of

electrical circuit breaker panels that controlequipment and lighting in their respective

areas. Circuits and equipment disconnects

must be identified

Dos and Don'ts


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Temporary or permanent storage of any

materials must not be allowed within 3 feet

of any electrical panel or electricalequipment.

Any electrical equipment causing shocks or

with high leakage potential must be taggedwith a Danger tag or equivalent.

Dos and Don'ts


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PORTABLE ELECTRIC TOOLS

Before you use a portable electric tool, make sure that it isproperly earthed, unless it is damaged-insulated (safely)tool.

Before using a double-insulated (safety) tool, make surethat the casing is undamaged, dont use the tool.

Make sure that all cables and plugs are in good conditionand adequately insulated.

use tools only on the correct power supply as instructed onthe makers label.

Make sure that the power cable is long enough to reachyour working place without straining it.

Dos and Don'ts


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PORTABLE ELECTRIC TOOLS

Dos and Don'ts

Keep power cables off the floor. They may get damaged or trip

somebody.

Never stand on a damp or wet surface when using electrical

equipment, and keep the equipment clean and dry.Never use a portable electric tool for work which it is not

intended.

Never connect a portable electrical tool to a lighting socket.

Never use worn, blunt or damaged bits or other accessories.

disconnect tools when not in use.Electric power tools should be regularly inspected and subjected

to planned maintenance.


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Dos and Don'ts


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AC reverse polarity is not hazardous.

It takes high voltage to kill; 120 volts is notdangerous.

Double insulated power tools are doubly

safe and can be used in wet and damplocations.

Myths and Misconceptions


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Rule 61,61A 67 : Connection with earth :

The following provision shall apply to the connection

with the earth of three phase systems for use at high

or extra high voltage. In the case of Star/Deltaconnected systems with

earthed neutral points:

Earthing system shall be tested for its resistances to

earth on a dry day during dry season not less thanonce in a year

Statutory Requirements


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Rule 63: Approval of Inspector is necessary before energizingany high voltage installation

Rule 92 : Protection against lightening.

Grant of certificate and Permit to Electrical supervisors/

Contractors. (Karnataka Rules 1976). Under this rule all electrical work shall be carried out only by

the personnel (Industrial/Contractor) who has obtainedrequired license, certificate or permit of competency to work inspecified category of electrical work in a prescribed forms.



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Indian Electricity Rules, 1956, Rule 6 All electrical supply lines of sufficient ratings for power,

insulation and estimated fault are current and of sufficientmechanical strength for the duty which they may be required toperform under the environmental conditions of installation and

they are constructed, installed, protected, worked andmaintained in such a manner as to ensure safety of humans,animals and property.

Indian Electricity Rules, 1956, Rule 47A

If the facility plans to install a generating plant, it gives a 30days notice of the intention to commission the plant to theelectricity supplier and the Electrical Inspector.



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In handling circuit known to be live -wherever possibleuse only one hand. It is best to keep the other handbehind your back. The most dangerous shocks are thosefrom hand to hand.

Line clear taken by one man should not be returned byany other.

Do not cut or remove ground wires under anycircumstances until you are directed to do so by properauthority in writing.

All portable equipment must be grounded.

Statutory Requirements General


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