Презентация на тему Electrical safety

(death due to electrical shock)

Electrical shock

Burns

Falls
Introduction

recognized hazards
Installation – in accordance with labeling
Marking – manufacturer’s

name, voltage, current, wattage

Disconnect switches- labeled to indicate the circuit’s function
Working clearances in front of electrical equipment
Guarding of live parts operating at 50 volts or more
Cabinets, secured rooms – proper labeling
Must also protect from physical damage (forklifts)

and welders
(*) Do not have to be trained if

they do not work close to exposed parts
Requirements depend on job tasks:
PPE, installation, safe clearances, skills to distinguish exposed parts, determine voltage

– opposition to current flow
Voltage – a measure of

electrical force
Conductors – substances, such as metals, that have little resistance to electricity
Insulators – substances, such as wood, rubber, glass, and bakelite, that have high resistance to electricity

on or near exposed electrical parts unless:
The part is

de-energized
The part is locked/tagged out

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
Low voltage does not mean low hazard

touch electrical wiring or equipment that is improperly used

or maintained
Typically occurs on the hands
Very serious injury that needs immediate attention

injuries
Workers in elevated locations who experience a shock

can fall, resulting in serious injury or death

is too small to safely carry the current
Example:

using a portable tool with an extension cord that has a wire too small for the tool
The tool will draw more current than the cord can handle, causing overheating and a possible fire without tripping the circuit breaker
The circuit breaker could be the right size for the circuit but not for the smaller-wire extension cord

a circuit, the current will heat the wires to

a very high temperature, which may cause a fire
If the wire insulation melts, arcing may occur and cause a fire in the area where the overload exists, even inside a wall

in the event of an overload or ground-fault in

the circuit
Include fuses, circuit breakers, and ground-fault circuit-interrupters (GFCIs)
Fuses and circuit breakers are overcurrent devices
When there is too much current:
Fuses melt
Circuit breakers trip open

equipment in locations where it would be exposed to

physical damage

fittings must have approved covers
Unused openings in cabinets, boxes

and fittings must be closed (no missing knockouts)

cords can be damaged by:
Aging
Door or window edges
Staples or

fastenings
Abrasion from adjacent materials
Activities in the area
Improper use of flexible cords can cause shocks, burns or fire

Wiring
Portable lamps,
tools or appliances
Stationary equipment-to facilitate interchange

fixed wiring
Run through walls, ceilings, floors, doors, or windows
Concealed

behind or attached to building surfaces

raise or lower equipment by its cord
Don’t unplug the

equipment by pulling on its cord
Don’t staple or fasten the cord so as to damage the outer jacket

parts
Deformed or missing parts
Damaged jackets or insulation

from service
Check the plug and receptacle mating configuration before

connecting

equipment and flexible cords
Ensure hands are dry
Never pull the

plug out by the cord

side rails when used near energized parts
Metal ladders can

conduct electricity and cause arcing and shocks

blown fuses

Warm tools, wires, cords, connections, or junction boxes

Ground

Fault Circuit Interrupter that shuts off a circuit

Worn or frayed insulation around wire or connection

https://www.youtube.com/watch?v=vhtQGQbuq6w

https://www.youtube.com/watch?v=WNot2owIv8c