Key Questions
The following key questions are answered in this module:
What are some of the dangers of an arc flash?
An arc flash poses several serious dangers. The temperature of an arc flash can be as high as 35,000 °F (19,400 °C). which is three to four times hotter than the surface of the sun. The radiation from this intense heat can severely burn and even kill. The flash produces intense light that can damage eyes or cause blindness. The heated air expands rapidly and produces pressure that can exert a force of several thousand pounds. An arc flash is hot enough to melt metal. Bits of metal in the blast can penetrate clothing and skin and cause contact burns. The force of the blast can cause collapsed lungs, broken bones, and permanent hearing damage.
What is the goal of NFPA 70E standard?
The National Fire Protection Association (NFPA) created the 70E standard called the "Standard for Electrical Safety in the Workplace". It is a guide for establishing safe work practices for personnel working with or near electrical equipment. NFPA 70E requires employers to implement an Electrical Safety Program appropriate to the risk associated with various electrical hazards.
What are the basics of a lockout tagout program?
Lockout tagout (LOTO) refers to a set of procedures that protect workers from the unexpected energization of machinery and equipment or the release of hazardous energy during service or maintenance activities. It involves shutting off energy at control points such as switches and circuit breakers and placing locks and tags on those controls to prevent the system from being re-energized. Before working on de-energized, locked or tagged out equipment, verify the equipment is safe.
What is "Hazardous Energy"?
Hazardous energy comes in many forms. In addition to electricity, pressurized fluids (or hydraulics), pressurized air (or pneumatics), springs under tension, or even an elevated position of a piece of equipment like backhoe scoop represent types of hazardous energy which need to be addressed when planning a job.
What is PPE Arc Rating?
PPE designed to protect from electrical and flame hazards may not withstand arc flash hazards. If there is an arc flash hazard, the PPE must be "arc-rated." Arc flash PPE categories range from 1, for the least risk, to 4, for the most significant risk. The lowest category has an arc rating of 4, or protects against a maximum incident energy of 4 cal/cm2. The highest category has an arc rating of 40.