Which method requires circuit protection devices to have individual ratings equal to or greater than the available fault current?

The full rating method requires that all circuit protection devices in a system have individual ratings that are equal to or greater than the available fault current. This ensures that each device can handle the maximum potential fault current without failing, thereby providing optimal protection for the entire circuit. By mandating that devices match or exceed the expected fault current, this method enhances system reliability and safety since the circuit breakers or fuses will not trip unnecessarily during normal operating conditions and will effectively handle any fault situations that occur.

In contrast, other methods like the series rating method and partial rating method allow for some flexibility in the ratings of protective devices, often relying on additional safeguards or conditions to ensure safety during fault events. The individual rating method, while similar in concept, emphasizes separate protection for each device rather than ensuring that every component meets the same high threshold of fault current handling capability.