Lockout tagout & electrical safety

Combat Edge, July, 2005 by Daryl Hammond

The air temperature exceeds 30,000[degrees]F, metal vaporizes, and high intensity UV radiation, X-rays, and a pressure wave are created with the release of over 1-million joules of energy ... a nuclear detonation? No, it's an electrical arc flash created when conductive objects such as wires, connectors, or tools get too close to a high amperage source. Electrical workers are faced with this danger every time they work on energized electrical equipment. An arcing flash releases tremendous energy, which explodes outward from the point of contact resulting in high temperatures that easily melt metal and copper wire, vaporizing it into plasma that conducts and is splattered through the air like shrapnel. The associated pressure waves can damage hearing or knock workers off ladders, and the flash is intensely bright; bright enough to damage eyesight.

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Exercising safe working practices and wearing proper protective equipment (PPE) are imperative. Complacency and noncompliance with regulations, safety procedures, and technical order guidance is not an option ... as there are often no second chances.

Dying to Get the Job Done

In the past year, the Civil Engineering (CE) electrical career field has experienced nine on-duty mishaps. Two of their finest have died: an Osan AB electrician while troubleshooting a transformer and cable insulation he thought was de-energized, and a Robins AFB electrician when a man-lift he was on overturned. Additionally, seven other electricians, both military and civilian, have been shocked and burned while working on energized equipment.

These statistics are both staggering and unacceptable. CE identified the top six causes of these electrical mishaps as failures to take the proper actions when working around high voltage. They were identified as failures to: test for voltage, ground circuits and/or equipment, follow lockout/tagout procedures, use appropriate technical orders (T.O.s), wear personal PPE, and seek supervisory assistance when performing tasks above expertise level. These certainly seem like pretty basic causes that can easily be applicable to any Air Force specialty where people work with electricity.

Using properly rated voltage meters and other testers is the only way to ensure power is off. Make sure meters work before and after testing. Many accidents have occurred when electricians took for granted their test equipment was working correctly when it actually was defective. Proper procedures and common sense tell us to ground phase conductors or circuit parts before touching them. By doing so, any stray voltage or current can be safely diverted to ground.

Energizing a circuit before work is completed results in catastrophic consequences ... make sure power stays off until the work is complete by strictly following lockout/tagout procedures. Ignoring or not following appropriate guidance such as those included in T.O.s results in equipment damage, injury, and death. Therefore, it is imperative that written guidance and procedures are used each and every time maintenance on equipment is accomplished.

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Electrical mishaps can occur even when proper safety procedures are followed. Wearing proper PPE can prevent serious injury or death, but many electricians fail to take the time to wear the proper clothing when they begin a task. Is it laziness, "have to get the job done attitude," or overconfidence? Maybe a combination of all three ... so take the time to plan and execute the job safely.

It's Not Luck

It's easy to blame Murphy or bad luck when things go wrong, but not knowing what to do when the unexpected is encountered and the worry of looking stupid by asking for help are ingredients for electrical disaster. Stay focused, alert, ask for help when needed, and take the time to do the job both correctly and safely.

Back to the Basics

What are the basics of establishing an electrically safe work environment for anyone working with electricity? The answer is simple ... ensure work is accomplished only on de-energized conductors or circuit parts that have been properly and safely isolated. Unfortunately, many electricians believe that de-energizing circuits is not necessary, too difficult to coordinate, or will jeopardize the mission. Many also believe that low voltage circuits can be worked on without de-energizing, when, in fact, exposure to as little as 50 volts could be fatal while exposure to anything over 240 volts has a high probability of being fatal.

Crew leaders and supervisors at all levels should review and ensure the following basic procedures are adhered to and are regularly briefed to all personnel because working on de-energized circuits, conductors, or circuit parts, establishes the safest environment for electrical workers. Let's review the basics:

1. Determine all possible sources of electrical supply. Just don't look at the obvious incoming feeders, but alternate sources of supply to the circuit, i.e., generators, tiebreakers or other circuit switches.