Electricity Hazards and Controls

Electricity is an integral part of our life and modern day cannot be imagined without it. But with all the benefit it brings in our life it has it also carries certain hazards which we are going to look at.

How the Electricity Works?

For electricity to work we need a source and a conductor. The source can be a power generator and wires can be conductors which can carry current.

What are Electrical Hazards?

Electrical Hazards can be as:

>Electric Shock

Electric Shock-contact with live conductor

Main type of harm from electricity is electric shock. An electric shock occurs when a person comes into contact with an electrical energy source. The electrical energy flows through a portion of the body causing a shock  (you become part of the circuit).

The effects of electric shock may include Heart failure, respiratory failure and burns.
Also, The passage of electric current through body causes muscles to contract violently. As a result you can become unbalanced and Fall off a ladder or hitting against some object on same level.

Severity of electric shock depends upon:

• The nature (AC or DC) and amount of current passing through the body.
• Path taken by the current through the body.
• Length of time body is in the circuit.
• Resistance of body to electric flow (young, old, wet)

>Arc Flash or Arc Blast

An arc flash (also called a flashover) is, part of an arc fault, a type of electrical explosion or discharge that results from a low-impedance connection through air to ground or another voltage phase in an electrical system.

Deadly Arc Flash while working with electricity

When an arc fault occurs, the result is a massive electrical explosion. The light and heat emitted by the explosion is known as the Arc Flash, and the pressure wave is known as the Arc Blast. An arc flash releases hot gases and concentrated radiant energy up to four times the temperature of the sun’s surface, which can melt metal and cause severe radiation .
It can cause severe burns, damage to eyesight, and even result in fatalities. And even if an arc blast doesn’t injure a person, it will damage equipment and cause downtime.

Electricity can also cause;

>Electrical Burns 
Typically occurs on hands when you touch electrical wiring or equipment that is improperly used or maintained.

>Fires
Fires of electric origin may be cause by overloading hazards. If too many devices are plugged into a circuit the current will heat the wire to a very high temperature which may cause a fire.
Or, If a wire insulation melts arcing may occur and cause a fire in the area where the overload exists even inside a wall.

Causes of Electrical Hazards:

Most electrical mishaps are caused by a combination of three factors:

1) Unsafe Work practices.

2) Unsafe equipment or installation.

3) Workplaces made unsafe by the environment.

Most deaths and injuries from electricity are due to:

• Using poorly maintained electrical equipment
• Working near overhead power lines
• Contact with underground power cables during excavation work
• Working near domestic electricity supplies
• Use of unsuitable electrical equipment in explosive atmospheres.

Preventing Electrical Hazards

Electrical hazards can be prevented through proper:
- Insulation
- Grounding
- Using of electrically protective devices.
- Safe work practices.

What to do if electrocution occurs?

In dealing with electricity never exceed your expertise

• Call for help.
• Do not touch the victim or the conductor.
• Shutoff the current at the control box.
• If shutoff is not immediately available, use a non-conducting material to free the victim.
• If necessary, begin CPR (Cardio Pulmonary Resuscitation ).

7 out of 10 victims revived when artificial respiration was given. But after three minutes the chances of revival decreases. 

Note:

To prevent contact with energized overhead power lines (cause of 45% of accidents in crane works)
> De-energize overhead lines
> Maintain minimum distance i.e,

• 10 feet distance for 50kv
• If over 50kv, add 4 inches per 10kv 

> Use proximity alarms
> Use of warning signs around source of high electric power.

Watch this video for safe escape from electrocution:
https://www.youtube.com/watch?v=AkwyxVEIDDM


For further details on electrical safety check;
NFPA 70E: Standard fr Electrical Safety in Workplace


Hope you've found this article informative and interesting. Keep tuned for more.