What should the AC volt meter indicate on the AC SYS CONTROL PANEL?

The correct range for the AC volt meter on the AC SYS CONTROL PANEL for the C-5 Auxiliary Power Unit (APU) is 112 to 118 VAC. This range is specified to ensure that the electrical systems powered by the APU receive a stable and adequate voltage level. Operating within this voltage range is critical for the reliable functionality of the aircraft's electrical systems, which includes starting and powering essential equipment. A voltage that is too low can cause inadequate power supply, potentially leading to malfunctions, while a voltage that is too high can damage components and increase wear.

The selection of this voltage range reflects the standard nominal voltage used in aviation systems, allowing for variations under load conditions while maintaining operational integrity. Understanding this range is essential for proper monitoring and maintaining the APU's performance in ensuring the aircraft's operational readiness.