Based on the example, which statements about available fault current relative to a panel's marked rating are correct?

• A. I only
• B. II only
• C. I and IV
• D. II and III

Answer: (C)

A panel’s marked rating defines the maximum short-circuit (fault) current it is designed to withstand at its terminals. The available fault current is the actual fault current the system could deliver to that point, determined by the source impedance and how the network is arranged. The safe, code-aligned position is that the available fault current must not exceed the panel’s marked rating. If the system could produce more fault current than the panel is rated to handle, protective measures or different equipment are required to prevent damage, overheating, or improper tripping.

Statements that align with this idea—that the panel’s rating sets an upper limit for the fault current at that location and that exceeding that rating is not acceptable—are the ones that describe the correct relationship. Any statement implying the panel can safely carry fault currents above its marking, or that the rating is not a governing limit, would be incorrect.