For short circuit testing, what type of current should the galvanic isolator be able to withstand?

The correct answer is that a galvanic isolator should be able to withstand AC current (RMS). This is because galvanic isolators are primarily designed to prevent galvanic corrosion by ensuring that no direct electrical connection exists between the shore power and the boat's electrical system. During a short circuit test, the isolator must be able to handle the expected fault currents that occur in typical AC systems, specifically alternating current (AC) at root mean square (RMS) values, which is the standard method of measuring AC current.

In marine applications, AC power is commonly used for various onboard systems, making it essential that the isolator can effectively manage the potential short circuit conditions encountered during testing. It's crucial to ensure the device can absorb and withstand these currents without failing or compromising the safety of the system.

The other types of currents, such as DC current, impulse current, and mixed current, may not accurately reflect the conditions under which most marine electrical systems operate and do not align with the main purpose of galvanic isolators in typical applications. This is why understanding the nature of the current the galvanic isolator must withstand is important for proper safety and functionality in marine electrical systems.