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Introduction

The aim of this training course is to provide information regarding electricity, static electricity, hazards associated and precautions that have to be taken, in order to prevent any incident or accident.

GENERATING ELECTRICITY

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• Electricity, How does it work?
• Friction, pressure, heat, light, chemical reaction, and magnetism,
• Magnetism is most practical & inexpensive method,
• Electricity is produced when a magnet is moved past a piece of wire, or wire is moved through a magnetic field.

ELECTRICAL TERMS

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• Current - electrical movement (measured in amps),
• Circuit - complete path of the current. Includes electricity source, a conductor, and the output device or load (such as a lamp, tool, or heater),
• Resistance - restriction to electrical flow,
• Conductors - substances, like metals, with little resistance to electricity that allow electricity to flow,
• Grounding - a conductive connection to the earth which acts as a protective measure,
• Insulators - substances with high resistance to electricity like glass, porcelain, plastic, and dry wood that prevent electricity from getting to unwanted areas.

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ELECTRICAL HAZARDS

Shall Always Be Supposed That All Electrical Lines And Equipment Are Energized And Hazardous, Until All Components Have Been Properly Isolated From Electrical Sources, Grounded, Tagged, Locked Out And Tested, By Attempted Re-Energisation.

ELECTRICAL HAZARDS

PRIMARY HAZARDS

• Electrocution (Electrical shock)
• Fire and Explosions.

SECONDARY HAZARDS

• Burns:
• Contact Burns;
• Flash Burns.
• Falls

ELECTRICAL HAZARDS

Electrocution (electric shock)

An electric shock can occur when human body is in contact with any source of voltage high enough to cause sufficient current flow through the body. The current may cause tissue damage or heart fibrillation if it is sufficiently high.

ELECTRICAL HAZARDS

Some Times high voltages lead to indirect injuries.

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High voltages can cause violent muscular contractions.

The indirect result can be injury resulting from a fall or even death if work is at high, or movement into machinery because of a shock.

THE EFFECTS OF ELECTRICAL CURRENT ON THE BODY

The danger from electrical shock depends on:

• the amount of the shocking current through the body,
• the duration of the shocking current through the body, and
• the passingway of the shocking current through the body.

Current passing through the body depends on:

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• Voltage applied
• Resistance of body and local conditions
• moisture of skin
• other factors (e.g. size, weight etc.)

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THE BODY RESISTANCE

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• Dry skin may have a resistance of 1,000,000 ohms. Wet skin may have a resistance of only 1,000 ohms.
• The low resistance of wet skin allows current to pass into the body more easily and give a greater shock.
• When more force is applied to the contact point or when the contact area is larger, the resistance is lower, causing stronger shocks.

THE PASSINGWY THROUGH THE BODY

• The path of the electrical current through the body affects the severity of the shock.
• Currents through the heart or nervous system are most dangerous.

THE PASSING THROUGH THE BODY

• If you contact a live wire with your head, your nervous system will be damaged.
• Contacting a live electrical part with one hand — while you are grounded at the other side of your body— will cause electrical current to pass across your chest, possibly injuring your heart and lungs.

EFFECTS OF ELECTRICAL CURRENT ON THE BODY

FIRST AID FOR PEOPLE SHOCKED BY ELECTRICITY

• Do not touch the victim yourself if he is still in contact with an electrical circuit!

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• Shut off the electrical current if the victim is still in contact with the energized circuit

• If you cannot get to the switchgear quickly, pull the victim from the circuit with something that does not conduct electricity such as dry wood.

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• Once that electrical current is no longer flowing through the victim, call the victim to see if he is conscious.

FIRST AID FOR PEOPLE SHOCKED BY ELECTRICITY

• If the victim is conscious, tell the victim not to move. It is possible for a shock victim to be seriously injured but not realize it.
• Quickly examine the victim for signs of major bleeding.
• If there is a lot of bleeding, place a cloth (such as a handkerchief or bandanna) over the wound and apply pressure.
• If the wound is in an arm or leg and keeps bleeding a lot, gently elevate the injured area while keeping pressure on the wound.
• Keep the victim warm and talk to him or her until help arrives.

FIRST AID FOR PEOPLE SHOCKED BY ELECTRICITY

• If the victim is unconscious, check for signs of breathing. While you do this, move the victim as little as possible.

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• If the victim is not breathing, someone trained in CPR should begin artificial breathing, then check to see if the victim has a pulse. Quick action is essential! To be effective, CPR must be performed within 4 minutes of the shock.

ELECTRICAL FIRES AND EXPLOSIONS

• Electricity is one of the most common causes of fires and thermal burns in homes and workplaces.
• Defective or misused electrical equipment is a major cause of electrical fires.
• If there is a small electrical fire, be sure to use multi -purpose (ABC) fire extinguisher or CO₂ fire extinguisher.

However, do not try to put out fires unless you have received proper training.

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If you are not trained, the best thing you can do is evacuate the area, raise the alarm, and call for help.

ELECTRICAL FIRES AND EXPLOSIONS

• An electrical explosion is the impulsive release of energy due to a short circuit between power phases or a phase to ground.
• It is important to realize that a very large amount of energy is available in many electrical panels when they are operating.

FIRE AND EXPLOSIONS: ELECTRICAL TRANSFORMERS

• More serious explosions occur when a short circuit causes the collapse of the magnetic field in the transformer.
• When this happens, there is an instantaneous release of the energy stored in the transformer in the form of a fault current.
• The most important aspect of designing an electrical system is to make sure that the protective fuses and circuit breakers are capable of handling the maximum available fault current.
• When fault current ratings are exceeded circuit breakers weld together and are unable to clear the fault.

FIRE AND EXPLOSIONS: ELECTRICAL TRANSFORMERS

CONTROLLING SITE ELECTRICAL HAZARDS

CONTROLLING SITE ELECTRICAL HAZARDS

• Inadequate wiring.
• Exposed electrical parts.
• Overhead power lines.
• Wires with bad insulation can give you a shock.
• Electrical systems and tools that are not grounded or double-insulated.
• Overloaded circuits.
• Damaged power tools and equipment.
• Using the wrong PPE.
• Using the wrong tool.
• Ladders that conduct electricity.
• Humidity and/or the worker, location, or equipment are wet.

CONTROLLING SITE ELECTRICAL HAZARDS

• Site electrical installation to comply with electrical safety standard,
• Only competent electrician for operation / maintenance,
• Electrical apparatus double isolated and/or grounded,
• Cable resistant and water proof,
• Temporary electrical cable shall be routed in safe manner, elevated by proper means and/or protected from damaged or trip,

CONTROLLING SITE ELECTRICAL HAZARDS

• Prevent shocking currents from electrical systems and tools by grounding them or utilizing double insulated tools.
• Prevent shocking currents by using GFCI's.
• Prevent too much current in circuits by using over current protection devices.
• Mantain safe distance from live parts, cable and equipment (min. 5 meters)
• Utilize only low volatge equipment in restricted places