THE NEW PIPER AIRCRAFT, INC.
PA-32-301FT / 301XTC
MAINTENANCE MANUAL
PAGE 27
Jun 1/03
2D15
21-50-00
(i) With both the low and high side valves open, continue the pumping and hold the system
below 26 in. Hg. for a minimum of 30 minutes. All the previous pumping time may be
included in the 30 minutes provided that no leaks or blockages are noted, and provided
that the system is not opened by removal or disconnection of components.
(j) Close the low and high side hand valves, stop the vacuum pump and perform the
charging procedure immediately.
(4) Charging the System Using the Airplane Compressor
This method is the least desirable due to the requirement of operating the airplane’s engine to
run the compressor.
CAUTION: ASCERTAIN THAT THE AREA AROUND THE AIRPLANE IS CLEAR AND THAT
A QUALIFIED PERSON IS AT THE CONTROLS OF THE AIRPLANE.
(a) Keep the system under the vacuum established during the evacuating procedure with
both hand valves in the closed position.
(b) Attach a container of the refrigerant (HFC-134a) to the manifold set and open the
container service valve.
(c) Loosen the center hose at the manifold set until a hiss can be heard. Allow the gas to
escape for 2 to 3 seconds, then tighten the connection.
(d) Open the high side manifold set hand valve, observe the low side gauge, then close the
high side hand valve. The low side gauge should immediately change from an indication
of a vacuum to an indication of pressure. If it does not, the system is blocked, and the
blockage must be corrected before proceeding.
(e) Start the engine and operate it at 1000 rpm.
(f) Adjust the airplane air conditioning controls for maximum cooling, high blower speed.
(g) Keep the refrigerant cylinder in an upright position. A slug of liquid refrigerant entering the
system would damage the compressor.
(h) Open the low side manifold set hand valve and allow two pounds of refrigerant in the gas
state to enter the system.
(i) Close the low side manifold set hand valve.
(j) Proceed with the Post Charging Operational Check, below.
(5) Post Charging Operational Check
CAUTION: ASCERTAIN THAT THE AREA AROUND THE AIRPLANE IS CLEAR AND THAT
A QUALIFIED PERSON IS AT THE CONTROLS OF THE AIRPLANE.
NOTE: Head the airplane into the wind during these checks.
(a) With the manifold set installed, and both hand valves closed, actuate the system and
operate the engine at 1,000 rpm for two minutes, then operate the system at 2,000 rpm
for 2 minutes.
(b) Check the system sight gauge (on the receiver-dehydrator) during operation at 1,000 and
2,000 rpm. Any indication of bubbles passing the sight gauge indicates that additional
refrigerant is required.
(c) Add additional refrigerant slowly through the low side manifold set hand valve until the
sight glass remains free of bubbles.
(d) Close the low side hand valve and refrigerant container valve.
To Next Page
Loading...
Need help?
General