System - Raytheon BEECH BARON 58P Maintenance Manual

BEECHCRAFT
BARON 5BP AND BARON 58TC
MAINTENANCE MANUAL
CABIN ALTITUDE CONTROLLER
FS 190.00 between the cabin
pressurization safety valve
and the aft air conditioner
evaporator
module.
Cabin altitude is maintained
by the cabin altitude controller
with the control anywhere from
zero
pressure
to maximum
The
secondary function of this solenoid is
to
eliminate
I
differential of
3.75 psi
on
TJ-3 thru TJ-168, except TJ-153
or
pressurization fluctuation during
ground
run-up and flight
3.9 psi
on
TJ-153 and TJ-169 and aRer. The controller is
when the
airplane is unpressurized.
rotated until the desired cabin altitude for flight is at the
index mark.
Any
selected cabin altitude will be maintained When
energized,
the solenoid valve allows
vacuum
to
be
during the flight provided the cabin pressure is at
or
below
applied
to
the control diaphragm which holds it in the
open
I
the ma*mum ditlerential
presswe.
n me cabin reaches the
posibbn allowing cabin
pressvre
to heely dump we~board.
maximum differential of 3.75 psi
on
TJ-3 thru TJ-168, except
The solenoid valve is
energized when the manual dump
TJ-153
or
3.9 psi
on
TJ-153 and TJ-169 and after and the
switch is in the dump position
or any
time the airplane is
on
airplane
is
still climbing, the cabin altitude will climb with the
the
ground. The
vacuum source
is
an
ejector, located aft
of
airplane.
If
a
cabin altitude change is required in Right it
can
the forward pressure bulkhead.
be accomplished by selecting the
new
cabin altitude. The
rate of change, both increase
or
decrease in pressure, will
RRESSURIZATION TEST SWITCH
be in accordance with the
setting
of the
rate
knob.
A pressurization
press-to-test switch is located
on
the
control console. The
momentary press-to-test
switch
de-
OUTFLOW VALVE AND SAFETY VALVE/DUMP
energizes
the solenoid valve
so
the pressurization
system
SOLENOID
can
be checked during
ground
run-up.
Pressurization
ground check may be accomplished
as
follows:
An outflow valve and safety valve/dump solenoid
are
located
on
the forward side of the aft pressure bulkhead,
a.
Place the manual
dump switch in the pressure
The outflow valve regulates cabin pressure up
to maximum position and the firewall shut-off valves in the open
position.
I
differential pressure of 3.75
psi
on
TJ-3 lhru TJ-168, except Set the controller below field elevation.
TJ-153,
or
3.9 psi
on
TJ-153 and TJ-169 and after, b. Run the
engines
at
2,000 rpm and press the
press-to-test switch.
A diaphragm in the
valve,
controlled by
the cabin attitude
c.
A momentary indication of descent in cabin
control, closes
to
the position
necessary
to maintain the altitude
on
the cabin rate-of-climb indicator shows
that the
selected pressure. This maintains the selected cabin
system will pressurize.
altitude up
to
maximum differential pressure. The differential
contml
feature of the valve maintains the cabin pressure
at
I
maximum differential pressure (3.75 psi
on
TJ-3 thru TJ- NOrr
168, except TJ-153,
or
3.9 psi
on
TJ-153 and TJ-169 and
after) only.
The differential control utilizes
a
diaphragm that
It is recommended that
high strength webbing
applies
pressure
against
a
spring-loaded needle valve.
(P/N
102-000402-0939
or
equivalent)
be
used
When cabin pressure teaches maximum differential to
encompass
fuselage
doors and windows for
pressure, the diaphragm pushes against
the needle valve,
safety of personnel during ground
allowing cabin air
to
bleed off into the tail section. As cabin
pressurization
operation by external
air bleeds off, the diaphragm allows the needle valve to
pressurization
Mower.
retum to its normal position; thus the diaphtagm modulates
the needle valve between the open and dosed position
to
maintain maximum differential pressure. The
safety
EJECTOR
valve/dump solenoid is the
same as
the outRow
valve,
however it controls differential pressure only. When the The ejector is located
on
the
right
sidewall
just
ah of FS
airplane touches down,
a
solenoid valve will
energize 39.00. Air from the pressure manifold passes through the
applying
vacuum
to
the control chamber of the safety valve larger side of
the ejector creating
a vacuum on
the smaller
and dump the cabin pressure overboard. The solenoid valve side of the
ejector. The
vacuum
lines connect to the
is
located
on
the right side of the ah pressure bulkhead
at
pressurization controller and
to
the
dump
solenoid valve.
21-30-00
Page 2
Mar 21180