Description (AMM 21-51-00)

 

The air conditioning systems provide conditioned air to the controlCabin, passenger cabin, electronic equipment compartment, forward cargo compartment, air conditioning distribution bay and aft cargo compartment. 

 

Air supply to the air conditioning system is furnished by the pneumatic system from either engine bleed air or the auxiliary power Unit (APU) in flight; from engine bleed air, APU bleed air, ground Pneumatic supply cart, or from a ground conditioned air supply cart During ground operation.

 

A pack valve closed limit switch provides a ground for the pack valve

closed relay to drive mix valve full cold after the pack valve closes.

The switch is actuated by the valve bellcrank.