Which boundary is defined as the approach limit at a distance from an exposed energized conductor where there is an increased likelihood of electric shock?

Which boundary is defined as the approach limit at a distance from an exposed energized conductor where there is an increased likelihood of electric shock?

• A. Restricted approach boundary
• B. Limited approach boundary
• C. Arc flash boundary
• D. Ground boundary

Answer: (A)

The concept being tested is how we define safe distances around exposed energized parts to protect workers from shock. The boundary described as the closest approach limit where shock risk is most likely is the restricted approach boundary. This boundary represents the distance from an energized conductor or part within which a shock hazard exists if protective measures aren’t in place. Crossing into this zone requires a qualified person, with appropriate PPE and procedures, because the chance of electric shock is higher there. The more distant boundary that still involves shock risk but is less immediate is the limited approach boundary, not the one described. Arc flash boundary relates to burn hazards from an arc flash, not the likelihood of shock. The ground boundary isn’t a standard boundary used for shock protection. So the correct boundary is the restricted approach boundary.

The concept being tested is how we define safe distances around exposed energized parts to protect workers from shock. The boundary described as the closest approach limit where shock risk is most likely is the restricted approach boundary. This boundary represents the distance from an energized conductor or part within which a shock hazard exists if protective measures aren’t in place. Crossing into this zone requires a qualified person, with appropriate PPE and procedures, because the chance of electric shock is higher there. The more distant boundary that still involves shock risk but is less immediate is the limited approach boundary, not the one described. Arc flash boundary relates to burn hazards from an arc flash, not the likelihood of shock. The ground boundary isn’t a standard boundary used for shock protection. So the correct boundary is the restricted approach boundary.