Mooney M20TN, Руководство по обслуживанию и ремонту

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MOONEY AVIATION COMPANY, INC.
M20TN SERVICE & MAINTENANCE MANUAL
Page
Date
11
2006
Rev Date
valve (BLUE). The suction pressure will increase to
60--70 PSIG while the R--134a refrigerant enters the
compressor.
NOTE:
As refrigerant enters the compressor, a slight
increase in discharge pressure will be noted
(2--5 PSIG).
11. Continue to add refrigerant per the above proce-
dure until the sight glass is clear of excessive bubbles
when charged on a hot day (95--105
o
F).
NOTE:
A desired sight glass liquid condition is when
only occasional bubbles are observed when
charging on a hot day (95--105
o
F).
12. Close suction manifold valve (BLUE) and let sys-
tem operate for 5--10 minutes and then check sight
glass. If sight glass is not totally clear, open suction
manifold valve and add a small quantity of refrigerant
until 98% of bubbles disappear. Close manifold valve
and let system stabilize.
NOTE:
Letting the system stabilize is required since the
expansion valve is trying to stabilize to the pre-
set suction pressure value.
-- CAUTION --
Do not overcharge system or component and
system damage may occur. Full system charge is
approximately 2.2 lbs. of R--134a.
13. With the system fully charged and operating, ob-
serve the suction and discharge pressures shown in
the following chart.
Typical values at various ambient temperatures, with
hot cabins, are shown in the following chart:
O.A.T. (
o
F)
SUCTION
PRESSURE
(PSIG)
DISCHARGE
PRESSURE
(PSIG)
60--70 28 125--140
80 30 170 +/-- 10
95 31 210 +/-- 10
105 32 237 +/-- 10
NOTE:
Whenever possible, the system should be
charged on a hot day (90--100
o
F). If not, ”topping
off” may be required for ambient conditions.
14. Allow system to operate for 10 minutes and then
shutdown.
-- CAUTION --
Do not allow aircraft engine temperatures to ex-
ceed limits.
NOTE:
After shutdown, both suction and discharge
pressures will begin to equalize. Pressures
should be equal in 60 -- 90 seconds.
15. Close refrigerant container shutoff valve (turn
C/W). Record the refrigerant container final weight and
calculate system refrigerant charge as follows:
CHARGE (lb.) = W initial (lb.) -- W final (lb.)
16. Turn knob on suction and discharge charging
hose quick coupler to closed position and disconnect
hoses from service ports.
17. Remove YELLOW charging hose from refriger-
ant container and store manifold gauge set.
-- CAUTION --
Hand and eye protection must be worn during
this operation to prevent subcooled refrigerant
from burning eyes or hands.
21--53--00 -- EXPANSION VALVE ADJUSTMENT
PROCEDURE
Even though the automatic expansion valves are set by
the manufacturer there may be times when it must be
adjusted to assure proper refrigerant flow. Any adjust-
ment must not affect system suction and compressor
discharge pressures as outlined in Section 21--52--03,
13. Changing expansion valve settings will also
change evaporator air output temperatures.
21--53--01 -- SPECIAL TOOLS AND/OR EQUIP-
MENT
The following tools and/or equipment are required to
perform expansion valve adjustment:
1. Assorted small hand tools.
2. Inspection mirror, adjustable
3. Thermometer, 0--150
o
F
4. Flashlight or service light
5. R--134a service manifold and gauge set
21--53--02 -- EVAPORATOR BALANCING PROCE-
DURE
Evaporator balancing is required on all systems with
multiple evaporator modules. This process balances
refrigerant flow between evaporators to achieve equal
evaporator air outlet temperatures. See Section
21--53--03, 1 through 10 above prior to beginning steps
below.
1. Access all evaporator modules and measure/re-
cord outlet air temperatures.
NOTE:
Typical temperature difference of evaporator inlet
and outlet air is 25+/-- 5
o
F.
2. If suction pressure is above the values outlined in
Section 21--52--03, 13, the adjustment screw of the
evaporator expansion valve, which has lowest outlet
temperature, must be turned OUT, in 1/2 revolution in-
crements.
21--53--00
AUGUST 2010