What should the DC volts meter indicate during operation?

The correct indication for the DC volts meter during the operation of the C-5 Auxiliary Power Unit (APU) is within the range of 28-32 VDC. This voltage range is optimal because the APU is designed to produce a stable DC output to effectively power the aircraft's systems during ground operations or while the main engines are off.

Maintaining this voltage range is crucial for ensuring that all connected electrical components operate efficiently and reliably. A voltage that is too low may not sufficiently power essential systems, while a voltage that is too high can lead to potential damage to those systems.

Understanding the operational range helps technicians monitor the APU's output and troubleshoot any issues that may arise during operation, ensuring the APU is functioning correctly and safely powering the aircraft systems.