RECIRC SWITCH (two-position)

• aft selection turns recirculation fan off

RECIRC - turns the fan on at high speed. ECU automatically selects slow speed when required

• the fan operates at slow speed only during single pack operation (and at start-up)

DUCTS TEMP GAUGE

• displays temperatures when selected by GAUGE selector in the:
• CABIN DUCT (supply) temperature
• CABIN temperature
• FLIGHT DECK DUCT (supply) temperature

GAUGE SELECTOR (rotary action)

• selects temperatures for display on the DUCT TEMP gauge:
• CABIN DUCT (supply) temperature
• CABIN temperature
• FLIGHT DECK (FC) DUCT (supply) temperature

PACKS CONTROL SWITCHES (three-position)

OFF - shuts related ACM off MAN, AUTO For both MAN and AUTO positions:

• modulates the pack Flow Control and Shut Off Valve
• packs start operating and supply conditioned air to the cabin and flight deck
• modulates the Pack Bypass Valve
• In accordance with the temp selections from the cockpit.

BLEED SWITCHES (two-position)

1 AND/OR 2 - starts bleed airflow from the No.1 and/or No.2 engines to the air conditioning packs. OFF - stops bleed airflow from the selected engine

BLEED CONTROL SELECTOR (rotary action)

• signals ECU to modulate the nacelle shut off valves
• provides airflow for one of three selected settings (for engine bleed operation) MIN - for minimum bleed airflow NORM - for moderate bleed airflow MAX - for maximum bleed airflow