G550 - Air Conditioning
The personal service units (PSUs), known as gaspers, are installed in both zones on each side of the cabin to supply cold air directly from the cold-air manifold.
This allows selection of cold air for individual comfort.
If the AUTO/MAN temp selector switches are in AUTO, the range of temperature control is:
One pack will shut off during in-flight starts. It will automatically go back to normal operation after in-flight start is complete.
The air-conditioning packs will not shut off during in-flight starts.
The selection of MAN allows direct control of each zone’s trim-air valve through its respective air conditioning controllers.
The power for cabin automatic temperature is from the left essential 28-VDC bus.
The left and right electronic equipment rack DC fans are positioned at or near the bottom of each rack. These fans change from high speed to low speed above _____
When operating on a single air-conditioning pack, the fan speed remains at high.
The air-conditioning controllers are dual-powered, dual-function microprocessors that provide airflow control through the packs and control pack outlet temperature.
The air-conditioning controllers also provide automatic temperature control of the cockpit and the forward and aft cabin zones.
The pack inlet valves (PIVs) are located in the pack bleed-air supply ducts, at the left and right of the forward fuselage.
The pack inlet valves (PIVs) are located in the pack bleed-air supply ducts, at the left and right of the tail compartment. They are controlled by a differential pressure servo valve which receives inputs from a torque motor to influence flow rates. A shutoff solenoid is incorporated to close the valve.
Moisture removed from the air by the pack is:
The cockpit airflow valve is an AC motor-driven butterfly valve with an orifice section. It is located in the cockpit conditioned-air supply duct aft of the cockpit silencer.
DC motor-driven butterfly valve! The valve restricts cockpit airflow by approximately 50% when closed.
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The _____ allows ram air to be fed directly into the left air-conditioning pack duct, supplying the cold-air manifold when ram air pressure exceeds cold-air manifold pressure.
The secondary pressure bulkhead separating the baggage compartment from the cabin has a sliding door that is required to be closed and locked above _____
What is the purpose of the ozone converters?
Ozone converters are installed for the left- and right-side cooling systems. Each one is mounted in its respective bleed-air ducting between the pack inlet valve and the inlets to the hot-air manifold and air-conditioning pack.
What does the ram-air switch do?
When ram air is selected, the left and right pack inlet valves are turned off, leaving ram air as the only means of cabin and cockpit ventilation, once differential pressure is zero.