For how long must galvanic isolators rated for 50 amperes or less be tested at 135% of their rated current?

Galvanic isolators rated for 50 amperes or less must be tested at 135% of their rated current for 1 hour to ensure they can withstand overcurrent conditions without failure. This duration is important as it allows for sufficient time to observe the performance of the isolator under stress, ensuring it can prevent galvanic corrosion effectively while handling the increased current load.

Testing galvanic isolators at this level and duration helps verify their reliability and functionality in real-life conditions where electrical systems may experience surges or overloads. Failing to conduct this test for the full hour might not provide an accurate assessment of the device's robustness, leading to potential failures in the marine environment where conditions can be harsh.

The other options, while they suggest varying durations, do not meet the specific requirements outlined for this type of testing. Only the 1-hour duration aligns with the established protocols for ensuring the safety and efficacy of galvanic isolators.