Which boundary is the approach limit at which a shock hazard exists from an exposed energized conductor or circuit part?

• A. Limited Approach Boundary
• B. Restricted Approach Boundary
• C. Arc Flash Boundary
• D. Insulation Boundary

Answer: (A)

Boundaries define how close a person can safely approach energized parts to prevent harm. The boundary that marks the distance where a shock hazard from an exposed energized conductor or circuit part begins is the Limited Approach Boundary. Outside this boundary, a shock hazard from those energized parts is not present for unqualified personnel under typical conditions. Inside this boundary, there is a real risk of electric shock, so only qualified individuals with proper training and protective equipment should approach—and they must observe additional controls as they move closer to the parts. The Arc Flash Boundary, by contrast, relates to thermal energy from arcing (burn hazards), not shock distance. The insulation boundary isn’t the standard term used for identifying shock risk in this context.