Electrical Hazards Analysis
For the most part, the electrical industry, at least at the user level, has largely ignored the subject of electrical hazards. There is a tendency to react to catastrophic accidents, rather than proactively trying to predict and prevent them. Recent changes in consensus standards, along with a better general understanding of the seriousness of electrical hazards have resulted in a renewal of interest in the subject.
As this awareness increases, the understanding of phrases like: “Limited Approach Boundary”, “Restricted Approach Boundary”, “Prohibited Approach Boundary”, and “Flash Protection Boundary” is essential. Below are the definitions of these terms as found in NFPA 70E-2004, Article 100: [1]
Limited Approach Boundary - “An approach limit at a distance from an exposed live part within which a shock hazard exists.”
Restricted Approach Boundary - “An approach limit at a distance from an exposed live part within which there is an increased risk of shock, due to electric arc over combined with inadvertent movement, for personnel working in close proximity to the live part.”
Prohibited Approach Boundary - “An approach limit at a distance from an exposed live part within which work is considered the same as making contact with the live parts.”
Flash Protection Boundary - “An approach limit at a distance from exposed live parts within which a person could receive a second degree burn if an electrical arc flash were to occur.”
Click here to read the full Electrical Hazards Analysis conducted by AVO Training Institute, Inc. The AVO Technical Resource Center provides electrical reference books, industry standards, training materials, personal protective equipment, insulated hand tools, and safety tools.
