Which statement describes how LPAC pressure control is achieved?

Which statement describes how LPAC pressure control is achieved?

• A. The Compressor Management System detects system pressure to control LPAC operation.
• B. The Fuel Oil Control System manages LPAC pressure.
• C. The Seawater Cooling System regulates LPAC operations.
• D. The Engine Control Module directly controls LPAC speed.

Answer: (A)

LPAC pressure is controlled by a feedback loop built into the Compressor Management System. It continuously monitors the air pressure in the system and responds by starting, stopping, or unloading the LPAC to keep the pressure near the commanded setpoint. When demand increases, the CMS increases output or brings the compressor online; when demand falls, it unloads or stops the compressor to avoid waste and overshoot. The other systems serve different functions—fuel oil control handles fuel supply, seawater cooling manages cooling, and the engine control module may influence engine speed but does not directly set LPAC pressure in this arrangement.

LPAC pressure is controlled by a feedback loop built into the Compressor Management System. It continuously monitors the air pressure in the system and responds by starting, stopping, or unloading the LPAC to keep the pressure near the commanded setpoint. When demand increases, the CMS increases output or brings the compressor online; when demand falls, it unloads or stops the compressor to avoid waste and overshoot. The other systems serve different functions—fuel oil control handles fuel supply, seawater cooling manages cooling, and the engine control module may influence engine speed but does not directly set LPAC pressure in this arrangement.