A fatal incident occurred involving a Non-Destructive Test (NDT) worker. The deceased was electrocuted while adjusting the position of portable lighting pole connected with trailing cable to distribution board which is 50 meters away. Medic at site performed CPR and brought the victim to site clinic and later taken to hospital where the Medical Doctor pronounced him dead. Preliminary finding shows that there was electricity leaking along the cable connecting to the lighting pole and that a few connections of the trailing cable which partly placed on wet ground.
Leading Causes of Electrical Accidents:
- Drilling and cutting through cables
- Using defective tools, cables and equipment
- Failure to maintain clearance distance of 10 feet
- Failure to de-energize circuits and follow Lockout/Tag-out procedures
- Failure to guard live parts from accidental worker contact
- Unqualified employees working with electricity
- Improper installation/use of temporary electrical systems and equipment
- By-passing electrical protective devices
- Not using GFCI (ground fault circuit interrupters) devices
- Missing ground prongs on extension cords
Hazards of Electricity
- Shock – Most common and can cause electrocution or muscle contraction leading to secondary injury, including falls
- Fires – Enough heat or sparks can ignite combustible materials
- Explosions ? Electrical spark can ignite vapors in the air
- Arc Flash – can cause burns ranging from 14,000 degrees f. to 35,000 degrees f
- Arc Blast ? In a short circuit event copper can expand 67,000 times. The expansion causes a pressure wave. Air also expands adding to the pressure wave
Small Activity, Big Outcome!
A man was electrocuted when his sweat dripped into the electric drill he was using to build a swing set in his backyard, the coroner said. ?Apparently the man was sweating profusely,? he said. ?He probably was pushing against the drill with his chest and his perspiration went into the drill itself and made a contact. Worker attempted to climb scaffold with electric drill. Drill?s cord was damaged with bare wires showing. The bare wire contacted the scaffolding. The worker died!?
- It is always necessary to check the insulation on equipment and cords before plugging them in.
- Remember, even the smallest defect will allow leakage!
?A worker was attempting to move mobile scaffold. Scaffold made contact with 7200 volt line. The worker died.?
- It is always necessary to check the location of overhead lines before you begin work each day.
- Remember; never allow yourself, your tools, or the materials you are working with to be within 10 feet of energized lines!
- It is always necessary to check that electrical boxes and panels are covered and free from missing ?knockouts?.
- Remember, electric equipment operating at 50 volts or more must be guarded!
- We can be safe by providing a separate, low resistance pathway for electricity when it does not follow normal flow (ground prong).
- Grounding gives the stray current somewhere to go and keeps you from becoming part of the circuit.
- Grounding will not work if the electricity can flow through you more easily than the ground.
Failed grounding can happen when:
- Your tool doesn?t have a ground pin.
- You?re working in wet locations.
- You?re touching a metal object.
- All circuits and extension cords.
- All noncurrent carrying metal parts.
- Portable & semi-portable tools and equipment unless double insulated.
Safe Work Practices
- Before work begins, we must determine where exposed and concealed electrical circuits are located.
- Once found, warning signs/labels must be posted.
- Workers need to know the location, hazards, and protective measures.
- Competent Person determines if performance of work could bring contact with energy.
- Distance of the worker to the energy source should be considered first.
- Tools, materials, and processes should also be considered to see if they could potentially shorten the safe separation distance. Examples include: Metal Ladders, Re-bar, Forklift, Scaffold Frames, etc.
- Must not permit work near electric circuits unless the worker is protected by:
- De-energizing the circuit and grounding it.
- Guarding it effectively by insulation.
- Other means (maintaining safe separation)
- De-energized circuits and equipment must be locked/tagged out.
- No metal ladders for or near electrical work.
- No wet hands when plugging or unplugging cords/equipment.No raising or lowering tools by the cord.
- Unless equipment is designed for it, cannot be used in damp and wet locations.