What percentage of rated current should be conducted through the isolator during the load test?

The appropriate percentage of rated current conducted through the isolator during a load test is 135%. This figure is crucial because it ensures that the isolator can handle overload conditions that may occur during regular operations or fault scenarios. By testing at this higher current level, it verifies the isolator's integrity, performance, and safety under stressed conditions that could be encountered in real-world applications.

Testing at 135% allows for assessment of the isolator's thermal and electrical characteristics beyond its normal operating limits, confirming its capacity to manage overload situations without failure. This is aligned with the standards set by organizations concerned with marine electrical systems, such as the ABYC, which emphasize safety and reliability in electrical installations.

Testing at lower percentages, such as 50%, 75%, or even 100%, may not reveal vulnerabilities that could lead to potential issues when the isolator is subjected to real-world conditions where it may need to handle more than just its rated current. Therefore, 135% is established to ensure robust performance and safeguard the electrical system against unforeseen stresses.