Learjet 60 - Cabin Climate Switches (R-12 and R-134 A Cooling Systems); CABIN FAN Switch; COOL-OFF Switch; CREW FAN Switch

Lexqet 60

Pilot's Manual
CABIN CLIMATE SWITCHES (142 and R4344 Cooling Systems)
COOL-OFF SWITCH
The COOL-OFF switch, located in the CABIN
CLIMATE group on the
copilot's switch panel, controls the freon
cooling system . When set to
COOL, the switch allows power to the freon compressor motor and
cabin and cockpit blower circuits . If either me CREW or CABIN FAN
switch is off when the switch is set to COOL, the respective blower,
cockpit or cabin, will run at minimum speed . Blower
speed may be in-
creased by rotating me CREW or CABIN FAN switch, as applicable, in
a clockwise direction until the desired speed is readied .
CABIN
FAN
SWITCH
Cabin blower speed is controlled during cooling and supplemental air
circulation modes by the rheostat-type CABIN FAN switch located in
the CABIN CLIMATE group on the copilot's switch
panel . Rotating the
switch clockwise out of me off decent position will turn on the cabin
blowers and blower speed will increase with further clockwise move-
ment . Power must be supplied by an engine generator, ground power
unit or APU . During pressurized flight (CAB AIR switch
ON), cabin
cooling is accomplished by pressurization airflow through the cabin
evaporator .
CREW FAN SWITCH
The rheostat-type CREW FAN switch is located in the CABIN
CLIMATE group
on the
copilot's switch
panel . The switch
control
the
cockpit blower which is available for all ground and inflight cooling or
air circulation modes .
When
the cooling system is in operation, the
blower will force air through the cockpit evaporator to provide cooling
or circulate air when the air circulation mode is selected .
Air circulated
by the cockpit blower is exhausted through the cockpit and cabin over-
head eyeball outlets when they are rotated to the open position .
HOURIVIETER
- COMPRESSOR (Aircraft 60-174 & Subsequent and
prior aircraft modified by SB 612 A2 -- Installation of Cooling Sys-
tem Compressor Motor Hour Meter)
An hourmeter may be installed
in the tailcone compartment
to measure
accumulated
compressor
usage time . The
hourmeter
is activated when-
ever the compressor motor is running . There is no separate circuit
breaker installed with this installation .
PM-123
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6-39
Change 4