Which boundary is the approach limit at which a shock hazard exists?

Which boundary is the approach limit at which a shock hazard exists?

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

Answer: (A)

Approach boundaries define how close you can get to exposed live parts to avoid electric shock. The outer boundary where a shock hazard exists is the limited approach boundary. Inside this boundary, a shock hazard is present, so only qualified personnel with the proper PPE and procedures should enter. The boundary that is even closer to the live parts is the restricted approach boundary, which demands stricter controls. The arc flash boundary deals with burn hazards from arcing, not shock risk, and the term ground boundary isn’t used for this purpose in NFPA 70E. So the limit at which a shock hazard exists is the limited approach boundary.

Approach boundaries define how close you can get to exposed live parts to avoid electric shock. The outer boundary where a shock hazard exists is the limited approach boundary. Inside this boundary, a shock hazard is present, so only qualified personnel with the proper PPE and procedures should enter. The boundary that is even closer to the live parts is the restricted approach boundary, which demands stricter controls. The arc flash boundary deals with burn hazards from arcing, not shock risk, and the term ground boundary isn’t used for this purpose in NFPA 70E. So the limit at which a shock hazard exists is the limited approach boundary.