TBT (Electrical Awareness)

Topic:        Basic Awareness of Electricity

Never ever take electricity for granted,

& never assume a circuit is dead.

Electricity is silent, invisible, and potentially fatal. Due to improper handling with electrical items, many cases have been observed inside the refinery and resulted in accident/incident, so it deserves the utmost respect.

The most common and serious electrical injuries occur when electrical current flows (form of electron) through the human body. This happens when a person touches an energized line/part. The electrical energy is looking for the shortest path to the ground, and it will pass through the body to the feet to reach it. When this occurs, a person’s heart and lungs are frequently damaged by the electrical energy.

Basic
Do’s & Don’ts to ensure electrical safety:

·
Do’s:

• Visual checks of plugs, sockets and cables prior to use – if any damage is identified then remove from service and report immediately.
• Ensure if any cable joins are required then utilize proper connector blocks, not just insulating tape.
• Visual check of electrical equipment that is to be used.
• Ensure the inner insulation of cables should never be visible – the outer insulation should extend into plugs and equipment and fully utilize cable grips.
• Ensure LOCK-OUT TAG-OUT If required to work on electrical equipment.
• Verify equipment is isolated using electrical tester before starting work.

·
Don’t:

• Use naked wires in sockets as horseplay.
• Touch any electrical equipment if not trained or authorized to do so which leads to near miss or any accident.
• Don’t use electric current distribution panels without protected and metal part without earthing.
• Overload electrical sockets – one plug per socket!
• Don’t wear any rings, watches or other materials which could conduct electricity while working on or in electrical cabinets / distribution boards.
• Don’t use electrical circuits without ELCB of 30 mA rating.
• Use water on electrical Fire.

Types of Electrical Hazards

Primary Hazards

Electric shock

Electric burns

(i)         Joules burns

(ii)        Fire and explosions

Causes of electric shock & fires

• Persons coming into contact with live conductors.
• Accidental contact with energy part of equipment.
• Insulation failure.
• Equipment failure.

i) Poor maintenance.

ii) Wrong work methods (overloading, makeshift wiring etc.).

iii) Substandard materials & workmanship.

iv) Un-authorized personnel.

v) Lack of training & knowledge.

• Short circuit.
• Spark from loose contacts.
• Mechanical damages.
• Loose connections.
• Heating of conductors, coils & equipment.
• Combustible materials nearby.
• Incorrect fuses.
• Wrongly set protective devices.
• Spark near flammable liquids, gases & vapours.

Control Methods

• Approved methods and procedures.
• Segregation of electrical equipment and flame proof equipment.
• Use of intrinsically safe circuits such as hand lamps / low voltage & small motors to driving instruments.
• Adopting standard codes of practice and use of equipment.
• Allowing only competent persons to work in the electrical system.

Burns 

Contact burns

• Coming in contact with live conductor.
• Accidental contact with energized metallic part.

Flash / Arc burns

• Arc burns received from flash over (while working with HV).
• Switchgears.
• Panels.
• Transformer installations.
• Short circuit arching.
• Burning of minerals.

Methods of Protection

• Following Indian electricity rules & work procedures.
• Licensed and authorized persons for electrical works.
• Approval from electrical inspectorate before installation energized.
• Periodical maintenance of installation and equipment.
• Proper replacement of damaged cables and equipment.
• Low voltage.
• Earthing.
• Double insulation.
• Current sensitive – tripping devices.
• Marking & warning.
• Observance of i.e., rules and regulations.
• Use of personal protective equipment.
• Training & education.
• Should have available with First Aider for Burns.
• First aid & firefighting.

How to protect / methods of protection against electrical accidents / injuries

• Proper o/l protection.
• Proper o/l setting.
• Flame proof motors.
• Regular / periodical inspection.
• Regular maintenance.
• Maintenance of earth pits.
• Lightning protection.

Earthing

Earthing means the conductor connection provided between any equipment / apparatus / service lines to the earth electrode with an extremely low electrical resistance. The earth electrode is a conductor of GI/CI pipe plate/rod buried underground surrounded by general mass of earth.