PS Magazine - TB 43-PS-706

PS, The Preventative Maintenance Monthly

ISSUE 706

SEPTEMBER 2011
PS Magazine - TB 43-PS-706 - Page 9 of 33
15
PS 706
SEP 11
***CAUTION***
Prior to engagement and
during operation of the A/C,
ensure the voltmeter needle
is in the green zone. Failure to
comply may result in damage
to equipment.
***CAUTION***
For A/C system operation in
ambient temperatures of 75
degrees Fahrenheit or less,
ensure that all instrument
panel vents are fully open
and the fan switch is on high.
Failure to comply may result in
damage to equipment.
***CAUTION***
Ensure service port caps are installed
and hand tightened. Failure to comply
may result in damage to equipment.
*goes between steps 12 and 13
*
a) Inspect compressor, clutch/pulley
assembly, and all A/C lines/hoses/fittings
for evidence of leaks.
b) Open all A/C vents. Turn A/C on, flip
fan switch to HI, wait 5 minutes to allow
temperature to stabilize.
c) During the 5 minute wait period, observe
the compressor clutch for rapid on/off
cycling. If rapid cycling is evident, shut off
A/C system.
d) Check air flow at the commander’s right
hand vent for cool air. If air at the vent is
not cooler than crew ambient, and/or rapid
cycling of the compressor clutch occurred,
initiate A/C troubleshooting.
Air
Conditioning
Semi-
annually
24.2
Changes for Mechanics
mechanics, you’ll need to make the following pmcs changes…
write in these changes to the pmcs table:
Finally, During the next maintenance of the A/C system, whether it
is a component replacement or just a refrigerant recharge, make
sure the thermostat switch, NSN 6685-01-539-
7
05
7
, label has a
gold background with black lettering.
The gold label switch
is designed to prevent the compressor from cycling/switching on before
validating available voltage, validating system pressure, or completely
disengaging based on a previous off signal. Thermostat switches with any
other color labeling should be replaced.
…in future
updates to
tm 9-2320-38
7
-10,
tm 9-2320-38
7
-24-1
and
tm 9-2320-38
7
-24-2.
on a separate sheet of paper, write the following two
cautions and pmcs item and insert it between pages 2-20
and 2-21 of tm 9-2320-38
7
-24-1 w/change 6.
in the space at
the bottom of
page 25-168.8
of tm 9-2320-
38
7
-24-2, add
the following
caution and
asterisk it to
go between
steps 12 and 13:
look for
these updated
a/c operating
and maintenance
changes…
1
2
3
706 14-15.indd
1-2
7/25/11
4:57 PM
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