What type of electrical system does the APU of the C-130J support?

The APU (Auxiliary Power Unit) of the C-130J supports a 28V DC electrical system. This output is specifically designed to power the aircraft's electrical systems during ground operations, particularly when the engines are not running. The 28V DC output is essential because it matches the standard voltage for most aircraft systems, allowing for consistent and reliable power to avionics, lights, and other equipment.

In aircraft design, the choice of voltage and electrical type is crucial for efficiency and safety. The 28V system provides a good balance of power for the various electrical loads while ensuring that the aircraft can operate effectively in various scenarios, such as on the ground with its engines off. This adaptability makes the APU an integral part of ground support operations, allowing for systems checks, preflight procedures, and other activities without needing to start the main engines, which saves fuel and reduces wear on the engines.

Alternatives like 12V AC or 48V AC systems are not compatible with the standard requirements for the C-130J. Aircraft typically utilize the 28V DC system to ensure compatibility with installed systems across military aircraft.