Learjet 60 - CAB AIR Switch; Crew AUTO-MAN Switch

Pilot's Manual
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Learjet 60
Whenever MAN mode is selected with either system AUTO-MAN
switch,
temperature control valve position is controlled by rotating
the CREW or
CABIN COLD-HOT selector switch . The rheostat type
switch will
vary
the
input current to the affected torque motor to
pneumatically position
the temperature control valve . Duct overheat
protection is
provided in this mode also .
Power for the
temperature control circuits is 28 VDC supplied
through the 1-amp
AUTO TEMP CONT circuit breaker on the copi-
lot's circuit
breaker panel (AUTO mode), and the
1-amp MANUAL
TEMP
CONTROL circuit breaker on the
pilot's circuit breaker panel
(MAN mode) .
CAB AIR SWITCH
The CAB AIR switch, on the
copilot's switch panel, controls the flow
control valve . With the BLEED AIR switches
ON, setting the CAB
AIR switch ON will de-energize the flow
control valve controlling so-
lenoid and allow system pressure to
the valve's controlling chambers .
Internal pressures will position
the valve shutoff sleeve, controlling
bleed-air flow to the heat
exchanger . Setting the CAB AIR switch OFF
will energize the
valve control solenoid which will shutoff control
pressure and
allow
the valve
shutoff sleeve to block bleed-air flow .
CREW AUTO-MAN
SWITCH
An
AUTO-MAN mode switch is located below the CREW
COLD-
HOT
selector on the copilot's switch panel . The switch provides auto-
matic or manual
mode operation for the cockpit temperature control
system
. When
AUTO
is selected, the cockpit temperature controller
will automatically position the cockpit temperature control valve
(through inputs to the torque motor) to maintain the temperature set
on the CREW
COLD-HOT selector . When MAN is selected, cockpit
temperature control
valve
position is
controlled directly from the
CREW COLD-HOT selector .
6-34
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PM-123
Original