A pathway shall be designated as Class _____ when it has fail-safe operation, where no fault is annunciated, but the intended operation is performed in the event of a pathway failure.

A pathway shall be designated as Class _____ when it has fail-safe operation, where no fault is annunciated, but the intended operation is performed in the event of a pathway failure.

• A. Class B
• B. Class C
• C. Class D
• D. Class E

Answer: (C)

Focusing on how a pathway behaves under fault conditions is what this classification is about. A pathway that continues to perform its intended action even when a fault occurs, and does so without signaling or annunciating the fault to operators, is described as Class C. This reflects a fail-safe design where the important operation still happens if the path fails, and there’s no fault indication presented. The other classifications would imply different fault signaling or behavior that doesn’t match the described scenario (for example, signaling a fault or not guaranteeing operation on failure). So Class C is the designation that best matches a fail-safe pathway with no fault annunciation and the intended operation taking place on pathway failure.

Focusing on how a pathway behaves under fault conditions is what this classification is about. A pathway that continues to perform its intended action even when a fault occurs, and does so without signaling or annunciating the fault to operators, is described as Class C. This reflects a fail-safe design where the important operation still happens if the path fails, and there’s no fault indication presented. The other classifications would imply different fault signaling or behavior that doesn’t match the described scenario (for example, signaling a fault or not guaranteeing operation on failure). So Class C is the designation that best matches a fail-safe pathway with no fault annunciation and the intended operation taking place on pathway failure.