Basic Electrical Safety

Objectives

Basics of Electricity Conductors and Insulators “Play It Safe, It’s The Law”

Objectives

Not designed to qualify you to work on electrical systems

Not designed to be inclusive of all regulations regarding working near electrical lines/facilities

As a reminder, if you identify problems with electrical systems, please report them immediately

Basics

Electricity flows in a completed path or loop Electricity will not flow until there is a complete loop Electricity will take the easiest and all paths to ground Electricity flows through conductors such as metal or

water Because the human body is mostly water, it is a

conductor of electricity

Basics Electricity is measured in different ways

Volts Amperes (Amps) Watts

Volts measure the “pressure” under which electricity flows. Amps measure the amount of electric current. Watts measure the amount of work done by a certain amount of

current at a certain pressure or voltage. To understand how they are related, think of water in a hose.

Turning on the faucet supplies the force, which is like the voltage. The amount of water moving through the hose is like the amperage. You would use lots of water that comes out really hard (like a lot of watts) to wash off a muddy car. You would use less water that comes out more slowly (like less watts) to fill a glass.

Effect on the Human Body

Shock Burns Electrocution

Have you ever been shocked?

More than 3 ma painful shock More than 10 ma muscle contraction “no-let-go”

danger More than 30 ma lung paralysis- usually temporary More than 50 ma possible ventricular fibrillation

(heart dysfunction, usually fatal) 100 ma to 4 amps certain ventricular fibrillation, fatal Over 4 amps heart paralysis; severe burns. Usually

caused by >600 volts

OSHA and State Plans

The following states have approved State Plans:

Alaska, Arizona, California, Connecticut, Hawaii, Indiana, Iowa, Kentucky, Maryland, Michigan, Minnesota, Nevada, New Jersey, New Mexico, New York, North Carolina, Oregon, Puerto Rico, South Carolina, Tennessee, Utah, Vermont, Virgin Islands, Virginia, Washington, and Wyoming

NOTE: The Connecticut, New Jersey, New York and Virgin Islands plans cover public sector (State & local government) employment only.

The Law

Chapter 752 of the Texas Health & Safety Code makes it unlawful for unauthorized persons to: move to, or place any objects, within six feet of any

high voltage overhead electric line (over 600 volts), or

to operate certain machinery or equipment within six feet of any high voltage overhead electric line

Chapter 752 also requires unauthorized persons to contact the owner of the lines 48 hours before work within these zones is started

Low Voltage Power Lines

Low Voltage is 600 volts or less Residential structures will be fed by single phase

lines from a transformer Commercial structures will be fed by three phase

lines from a transformer The minimum approach distance for low voltage lines

is 3 feet for insulated lines The minimum approach distance for low voltage lines

is 10 fee for uninsultated lines

Know Before You Dig

Electric cables can also be buried underground Under streets Under alleys Buried in residential yards

Call before you dig 1-800-DIG TESS (344-8377)

Items to Consider

Scaffolding Extension ladders Metal poles Trenching machines Shovels Tools

Do plug power equipment into wall receptacles with power switches in the “Off” position.

Do unplug electrical equipment by grasping the plug and pulling. Do not pull or jerk the cord to unplug the equipment.

Do not drape power cords over hot pipes, radiators or sharp objects.

Do check the receptacle for missing or damaged parts. Do not plug equipment into defective receptacles. Do check for frayed, cracked, or exposed wiring on

equipment cords.

Do and Do Not

Do check for defective cords clamps at locations where the power cord enters the equipment or the attachment plug.

Do not use extension cords in office areas. Do not use “cheater” plugs, extension cords with

junction box receptacle ends. Do know the location of electrical circuit breaker

panels that control equipment and lighting in their respective areas. Circuits and equipment disconnects must be identified.

Do and Do Not

Questions?

Jeff O’Connor

TXU Electric Delivery

Safety Coordinator

500 N Akard

LP 11041

Dallas, TX 75201