(Part IV) (2 of 2) Construction Focus Four: Electrocution Hazards

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How can I protect myself from electrocution hazards?

A. Maintain safe distance from overhead power lines

Staying away from power lines is the best option. Before work begins:

  • Ensure that the equipment/activity (such as cranes and other high reaching equipment) is located within a safe working distance from power lines.
  • Use nonconductive ladders and be sure to retract them before moving.
  • Ensure that no materials are stored under power lines.
  • Use caution tape and signs to cordon off area under power lines.

Electrical poles

B. Use Ground-Fault Circuit Interrupters (GFCI)

A GFCI is a ground fault circuit interrupter that is designed to protect people from severe and sometimes fatal electrical shock. A GFCI detects ground faults and interrupts the flow of electric current, and is designed to protect the worker by limiting the duration of an electrical shock. There are three types of GFCI.

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B.1 Receptacle GFCI: It is often found on construction work sites, outdoor areas and other locations where damp conditions do or could exist. The receptacle GFCI fits into the standard outlet box and protects users against ground faults when an electrical product is connected to the GFCI protected outlet. These should be tested after installation and once a month.

B.2 Temporary/Portable GFCI: Portable GFCI is an extension cord combined with a GFCI. It adds flexibility in using receptacles that are not protected by GFCls. Extension cords with GFCI protection incorporated should be used when permanent protection is unavailable. These should be tested prior to each and every use.

B.3 Circuit Breaker GFCI: The GFCI circuit breaker controls an entire circuit, and is installed as a replacement for a circuit breaker on the main circuit board. Rather than install multiple GFCI outlets, one GFCI circuit breaker can protect the entire circuit. At sites equipped with circuit breakers, this type of GFCI might be installed in a panel box to give protection to selected circuits. Circuit breaker GFCIs should be tested monthly. Keep in mind that the test will disconnect power to everything on the circuit.

C. Inspect portable tools and extension cords

Workers need to inspect extension cords prior to their use for any cuts or abrasion. Extension cords may have damaged insulation. Sometimes the insulation inside an electrical tool or appliance is damaged. When the insulation is damaged, exposed metal parts may become energized if a live wire inside touches them. Electric hand tools that are old, damaged, or misused may have damaged insulation inside. Flexible cords used with temporary and portable lights shall be designed for hard or extra-hard usage.

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D. Use power tools and equipment as designed

Workers need to know that even when the power system is properly grounded, electrical equipment can instantly change from safe to hazardous because of extreme conditions and rough treatment. Workers using power tools and equipment should follow tool safety tips to avoid misusing equipment.

  • Never carry a tool by the cord
  • Never yank the cord to disconnect it
  • Keep cords away from heat, oil, and sharp edges
  • Disconnect when not in use and when changing accessories such as blades and bits
  • Avoid accidental starting. Do not hold fingers on the switch button while carrying a plugged-in tool
  • Use gloves and appropriate footwear
  • Store in dry a place when not using
  • Don’t use in wet/damp environments
  • Keep working areas well lit
  • Ensure that cords do not cause a tripping hazard
  • Remove damaged tools from use

E. Follow lockout/tagout procedure

Lockout/tagout is an essential safety procedure that protects workers from injury while working on or near electrical circuits and equipment. It also prevents the unexpected release of hazardous gases, fluids, or solid matter in areas where workers are present.

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To protect against being electrocuted, workers need to follow lockout/tagout procedures. When performing lockout/tagout on circuits and equipment, the following checklist can be used:

  • Identify all sources of electrical energy for the equipment or circuits in question
  • Disable backup energy sources such as generators and batteries
  • Identify all shut-offs for each energy source
  • Notify all personnel that equipment and circuitry must be shut off, locked out, and tagged out (Simply turning a switch off is not enough)
  • Shut off energy sources and lock switch gear in the OFF position. Each worker should apply his/her individual lock and keys kept with the worker
  • Test equipment and circuitry to ensure they are de-energized. This must be done by a qualified person
  • Deplete stored energy (for example, in capacitors) by bleeding, blocking, grounding, etc.
  • Apply a lock or tag to alert other workers that an energy source or piece of equipment has been locked or tagged out
  • Make sure all workers are safe and accounted for before equipment and circuits are unlocked and turned back on. Only a qualified person may determine when it is safe to re-energize circuits.

(Part I) (1 of 2) Construction Focus Four: Fall Hazards

(Part I) (2 of 2) Construction Focus Four: Fall Hazards

(Part II) (1 of 2) Construction Focus Four: Struck-By Hazards

(Part II) (2 of 2) Construction Focus Four: Struck-By Hazards

(Part III) (1 of 2) Construction Focus Four: Caught–In or –Between Hazards

(Part III) (2 of 2) Construction Focus Four: Caught–In or –Between Hazards

(Part IV) (1 of 2) Construction Focus Four: Electrocution Hazards

Also Read:

Fire Prevention and Fire Protection – Air Pollution in Kathmandu – Construction PPE – Carbon Monoxide poisoning – Electrical Safety – Fall Protection in General Industry– Fearsome 4 of Construction Safety – Fall Restrain System Vs. Fall Arrest System – Respiratory Protection – Portable Ladder Safety – Confined Space Entry – Initiating First Aid/CPR – Are you too busy… – If you have $86,400 in your account…

(Part IV) (1 of 2) Construction Focus Four: Electrocution Hazards

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What is an electrocution hazard?

Electrocution results when a person is exposed to a lethal amount of electrical energy. An electrical hazard can be defined as a serious workplace hazard that exposes workers to Burns, Electrocution, Shock, Arc flash, Fire, Explosion, etc. BE SAFE by recognizing, avoiding and protecting against all of these electrical hazards.

What are the common types of electrocution hazards in construction?

A. Contact with overhead power lines

Overhead and buried power lines are especially hazardous because they carry extremely high voltage. Voltages of overhead lines range from 120 to 750,000 volts. Workers may not realize that cranes are not the only equipment that reaches overhead power lines. Working on a ladder or in a man-basket suspended under or near power lines also poses a risk of electrocution.

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B. Contact with energized sources

The major hazards regarding contact with energized sources are electrical shock and burns. Electrical shock occurs when the body becomes part of the electric circuit, either when an individual comes in contact with both wires of an electrical circuit, one wire of an energized circuit and the ground, or a metallic part that has become energized by contact with an electrical conductor.

The severity and effects of an electrical shock depend on a number of factors, such as the pathway through the body, the amount of current, the length of time of the exposure, and whether the skin is wet or dry. Water is a great conductor of electricity, allowing current to flow more easily in wet conditions and through wet skin.

Electrical burns can be arc burns, thermal contact burns, or a combination of burns. Electrical burns are among the most serious burns and require immediate medical attention. They occur when an electric current flows through tissue or bone, generating heat that causes tissue damage. The body cannot dissipate the heat generated by current flowing through the resistance of the tissue therefore, burns occur.

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C. Improper use of extension and flexible cords

The normal wear and tear on extension and flexible cords can loosen or expose wires, creating a hazardous condition. Cords that are not 3-wire type, not designed for hard-usage, or that have been modified, increase the risk of electric shock. With the wide use of power tools on construction sites, flexible extension cords are often necessary. Because they are exposed, flexible, and unsecured, they are more susceptible to damage than fixed wiring. Hazards are created when cords, cord connectors, receptacles, and cord- and plug- connected equipment are improperly used and maintained.

To reduce hazards, flexible cords must connect to devices and to fittings in ways that prevent tension at joints and terminal screws. A flexible cord may be damaged by door or window edges, staples and fastenings, abrasion from adjacent materials, or simply by aging. If the electrical conductors become exposed, there is a danger of shocks, burns, or fire.

When a cord connector is wet, electric current can leak to the equipment grounding conductor, and to anyone who picks up that connector if they provide a path to ground. Such leakage can occur not just on the face of the connector, but at any wetted portion.

(Part I) (1 of 2) Construction Focus Four: Fall Hazards

(Part I) (2 of 2) Construction Focus Four: Fall Hazards

(Part II) (1 of 2) Construction Focus Four: Struck-By Hazards

(Part II) (2 of 2) Construction Focus Four: Struck-By Hazards

(Part III) (1 of 2) Construction Focus Four: Caught–In or –Between Hazards

(Part III) (2 of 2) Construction Focus Four: Caught–In or –Between Hazards

(Part IV) (2 of 2) Construction Focus Four: Electrocution Hazards

Also Read:

Fire Prevention and Fire Protection – Air Pollution in Kathmandu – Construction PPE – Carbon Monoxide poisoning – Electrical Safety – Fall Protection in General Industry– Fearsome 4 of Construction Safety – Fall Restrain System Vs. Fall Arrest System – Respiratory Protection – Portable Ladder Safety – Confined Space Entry – Initiating First Aid/CPR – Are you too busy… – If you have $86,400 in your account…