COOLING. (PA-44-180T ONLY.)
GENERAL.
AIR CONDITIONING SYSTEM DESCRIPTION AND PRINCIPLES OF OPERATION.
The air conditioning installation is a recirculating, independent unit consisting of a compressor, evaporator,
condenser, receiver-dehydrator, circulating fan, thermal expansion valve and related plumbing.
Air is filtered, dehumidified and cooled by the evaporator. The evaporator is mounted in a fabricated housing,
along with the receiver-dehydrator, pressure switch, circulating fan and thermal expansion valve. This housing is
located at the rear of the cabin aft of the baggage area. The compressor is a piston type unit mounted at the front
of the port engine. A V-belt connection drives the compressor through a magnetic clutch. The condenser is
installed in the tail cone between stations 156.00 and 191.00.
The system is protected by a pressure switch which automatically controls the condenser maximum head
pressures by temporarily de-clutching the compressor in the event the pressure becomes excessively high.
The air conditioner controls are located on the right side of the aircraft instrument panel and consist of an air
conditioning ON-OFF control, a two-position fan control (LOW-HIGH) and a temperature control.
The air conditioning system uses Refrigerant 12. The refrigerant enters the compressor as a vapor. The
compressor pressurizes the heat laden vapor until its pressure and heat reach a point much hotter than the outside
air then pumps the vapor to the condenser where it is cooled and changed to a liquid. The liquid then passes to
the receiver-dehydrator. The function of the receiver-dehydrator is to filter, remove any moisture and insure a
steady now of liquid refrigerant into the evaporator through the expansion valve. The expansion valve is a
temperature controlled metering value which regulates the flow of liquid refrigerant to the evaporator to allow all
the liquid to evaporate and return to the compressor at a reduced pressure. From the evaporator, the refrigerant
vapor returns to the compressor where the process is repeated.
TROUBLESHOOTING.
A troubleshooting chart is provided to assist in locating and correcting possible malfunctions in the cooling
system.
— Note —
The air conditioning system should be operated at least once a month to prevent
sticking valves and to keep the system lubricated
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
2 1 - 5 1 - 0 2
Page 21-48
Revised: May 15, 1989
1G15
PIPER AIRCRAFT
Summary of Contents for SEMINOLE PA-44-180
Page 38: ...CHAPTER DIMENSIONS AND AREAS 1B14...
Page 49: ...CHAPTER LIFTING AND SHORING 1C1...
Page 53: ...CHAPTER LEVELING AND WEIGHING 1C5...
Page 58: ...CHAPTER TOWING AND TAXIING 1C10...
Page 62: ...CHAPTER PARKING AND MOORING 1C14...
Page 65: ...CHAPTER REQUIRED PLACARDS 1C17...
Page 70: ...CHAPTER SERVICING 1C22...
Page 98: ...CHAPTER STANDARD PRACTICES AIRFRAME 1E2...
Page 108: ...CHAPTER ENVIRONMENTAL SYSTEM 1E12...
Page 189: ...CHAPTER AUTOFLIGHT 1H21...
Page 192: ...CHAPTER COMMUNICATIONS 1H24...
Page 202: ...CHAPTER ELECTRICAL POWER 1I10...
Page 228: ...CHAPTER EQUIPMENT FURNISHINGS 1J12...
Page 233: ...CHAPTER FIRE PROTECTION 1J17...
Page 238: ...CHAPTER FLIGHT CONTROLS 1J24...
Page 304: ...2A18 CHAPTER FUEL...
Page 325: ...2B17 CHAPTER HYDRAULIC POWER...
Page 357: ...2D1 CHAPTER ICE AND RAIN PROTECTION...
Page 414: ...CHAPTER LANDING GEAR 2F13...
Page 479: ...2I6 CHAPTER LIGHTS...
Page 488: ...2I16 CHAPTER NAVIGATION AND PITOT STATIC...
Page 503: ...2J7 CHAPTER OXYGEN...
Page 524: ...2K6 CHAPTER VACUUM...
Page 535: ...2K19 CHAPTER ELECTRICAL ELECTRONIC PANELS AND MULTIPURPOSE PARTS...
Page 546: ...INTENTIONALLY LEFT BLANK PA 44 180 180T AIRPLANE MAINTENANCE MANUAL 2L6 PIPER AIRCRAFT...
Page 547: ...2L7 CHAPTER STRUCTURES...
Page 582: ...CHAPTER DOORS 3A18...
Page 593: ...CHAPTER STABILIZERS 3B8...
Page 604: ...CHAPTER WINDOWS 3B22...
Page 611: ...CHAPTER WINGS 3C10...
Page 624: ...CHAPTER PROPELLER 3D1...
Page 643: ...CHAPTER POWER PLANT 3D21...
Page 667: ...CHAPTER ENGINE FUEL SYSTEM 3F1...
Page 681: ...CHAPTER IGNITION 3F16...
Page 712: ...CHAPTER ENGINE INDICATING 3H1...
Page 730: ...CHAPTER EXHAUST 3H19...
Page 734: ...CHAPTER OIL 3I1...
Page 743: ...CHAPTER STARTING 3I11...
Page 755: ...CHAPTER TURBINES 3J1...