If actual incident energy is higher than the calculated energy, PPE adequacy may be insufficient.

• A. True
• B. False
• C. Not necessarily
• D. Only if near boundary

Answer: (A)

PPE adequacy depends on incident energy ratings. Arc flash PPE is chosen to withstand a specific amount of incident energy, usually expressed in cal/cm^2. The energy released in an arc flash is estimated through calculations (or measurements) that assume worst-case conditions, but those calculations are still estimates. If the actual incident energy ends up higher than what was calculated, the PPE may not provide the level of protection it’s rated for, leaving you vulnerable to burns. In practice, that’s why engineers design PPE selections to meet or exceed the worst-case energy at a given location, maintaining a margin to account for real-world variations. So the statement is true: actual energy higher than calculated energy can render the PPE insufficient.