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AirComm Corporation Cabin Air Conditioner A119 Instructions for Continued Airworthiness User Manual
AirComm Corporation Cabin Air Conditioner A119 Instructions for Continued Airworthiness User Manual
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AIR CONDITIONER SERVICE MANUAL A119-206M-1 Revision 12 Page 25 CHAPTER 6 SERVICING 1. Safety Precautions CAUTION Refrigeration servicing should be performed by qualified personnel only. The refrigerant used in the air conditioning system is the environmentally safe HFC R134a. This refrigerant is non-explosive, non-flammable, and non-corrosive, has practically no odor, and is heavier than air. Although R134a is classified as a safe refrigerant, certain precautions must be observed to protect the parts involved and the person working on the system. Liquid R134a at normal atmospheric pressure and temperature evaporates quickly and tends to freeze anything that it contacts. Care must be taken to prevent any refrigerant from coming into contact with the skin and the eyes. WARNING Always wear safety goggles when servicing any part of the refrigerant system. Should any liquid refrigerant contact the skin or eyes, seek medical attention immediately even if the irritation ceases. WARNING Never weld, use a flame-type leak detector, blow torch, solder, steam clean, bake on aircraft finish, or use excess amounts of heat on, or in the immediate area of refrigerant supply tank. 2. Servicing Information A list of suggested servicing equipment is provided later in this chapter. Servicing Procedure A. Connect the service manifold and vacuum pump to the service ports located in the upper deck aft of the compressor assembly. B. Turn on the vacuum pump and open both valves to evacuate the system. When the pressure drops to 29.40 InHg (1.9 KgCm) moisture vaporizes and is drawn out of the system by the vacuum pump. Complete removal of moisture is important to prevent blockage of the expansion valves with ice. Leak check the system as described later in this chapter. NOTE Due to the drop in atmospheric pressure with an increase in altitude, the normal vacuum reading will drop approximately 1” InHg (1 KgCm) for each 1000 ft. (304.8 m) of altitude. C. After the system has been evacuated, turn off both manifold valves and turn vacuum pump off. Allow a minimum of one hour to check for vacuum leaks (if the system will not
AIR CONDITIONER SERVICE MANUAL A119-206M-1 Revision 12 Page 26 hold a vacuum, the system has a fitting leak). It may be necessary to charge the system with one or two lbs. (.45 to .86 Kg.) of refrigerant and conduct a leak check survey using an electronic leak detector. CAUTION It is mandatory that the system be leak free to insure trouble free operation. Continuous operation of the system with insufficient charge will result in reduced compressor life. D. After the system is proven to be leak free, the system should be evacuated for a minimum of 1/2 hour before being charged with HFC R134a. E. Charging the system with 2.5 lbs. (1.13 Kg.) of R134a refrigerant is the most accurate method of charging. This should be accomplished using the suggested servicing equipment called out in this chapter. F. If a charging station is unavailable, the following procedure should be followed. Add an initial refrigerant charge of 2.0 lbs. (0.9 Kg.) then continue to add refrigerant until the evaporator outlet air temperature and system suction pressures reach a minimum. When adding the refrigerant after the initial charge, it should be done in increments of 0.2 lbs. (.09 Kg.) and two minutes allowed to elapse before adding each additional 0.2 lbs. (.09 Kg.) refrigerant charge. The optimum charge occurs when evaporator outlet temperatures are at their lowest. Any additional refrigerant will cause the outlet air temperature to increase and system performance to be degraded. WARNING If the system is to be charged by operating the compressor, it must be charged through the Lo (Blue fitting) pressure (suction) port only. Do not open the Hi (Red fitting) pressure (discharge) valve while the system is operating. G. Test-run the system after charging, to confirm the system is working properly. CAUTION When reclaiming refrigerant, be sure to note any oil that is removed from the system, and replace the lost oil before or during re-servicing. Reduced compressor life will result if the total system oil charge is not maintained. SYSTEM REFRIGERANT & OIL CHARGE System Description Refrigerant Charge Oil Charge A119 Air Conditioner 2.5 lbs. 1.13 kg. 7.5 fl. oz. 222.7 ml. 3. Lubrication Information The total system oil charge is 7.5 fl. oz. (222.7 ml.) of R134a Polyester Refrigerant Oil. The compressor is charged with 3.5 fl. oz. (103.9 ml.) of oil at the factory, an additional
AIR CONDITIONER SERVICE MANUAL A119-206M-1 Revision 12 Page 27 4.0 fl. oz. (118.8 ml.) of oil must be added at the time of the system installation. This oil should be added to the compressor discharge line prior to system charging. If oil is spilled during installation / maintenance, or is lost due to a leak in the system, it is necessary to approximate the amount of lost oil and add this amount to the system. The oil charge is continuously circulated by the refrigerant during the operation of the system. A quantity of oil is trapped by the compressor. NOTE Maintaining the correct amount of refrigerant and refrigerant oil in the system is critical for ensuring the long life of the compressor. The Service Ports for this system are located in the upper deck aft of the compressor assembly. CAUTION This system is serviced with Polyester Based Refrigerant Oil. The use of Polyalkylene glycol (PAG), or Mineral Oil in this system will cause damage to the air conditioner compressor and expansion valves. 4. System Leak Check Identification and elimination of system fitting leaks is extremely important to insure a trouble-free operation of this system. A system which contains a partial charge of refrigerant can be leak tested with the aid of an electronic leak detector, and be recharged without evacuating the system. A new or empty system can be pressurized with nitrogen 70-80 psi (5.1-5.6 kg/cm) or R134a 50 psi (3.5 kg/cm) to conduct a leak survey. CAUTION Do not use compressed air. Compressed air will introduce moisture into the system, which will degrade the operation of the system. The preferred method to conduct a leak survey is to use an electronic leak detector in conjunction with a small charge of R134a refrigerant. All checks done in this manner should be conducted with the air conditioner off. Since the refrigerant is heavier than air, leaks are most likely to be detected on the underside of hoses and fittings. Refrigerant will collect in low areas and provide erroneous leak detection. A stream of compressed air from a nozzle may be useful in clearing the area just prior to conducting a leak test. If the nitrogen method is used, it will be necessary to mix together a water and mild soap solution. Each fitting or suspected leak area should be brushed with this soap solution and watched for evidence of bubbles formed by the escaping nitrogen. If a leak is detected at an O-ring fitting, check to insure proper torque has been applied to the fitting. If the system continues to leak, reclaim the system of refrigerant, and install new O-rings.
AIR CONDITIONER SERVICE MANUAL A119-206M-1 Revision 12 Page 28 NOTE Ensure that the O-ring is lubricated with refrigerant oil prior to its installation. A small amount of leakage (approximately one ounce per year) past the compressor shaft seal is normal. Most leak detectors are sensitive enough to show a leak of this magnitude. 5. Suggested Equipment for Servicing Recovery / Recycling / Recharging Station (Example: Snap-on Model ACT 3340, Robinair Model 34700, or equivalent) Electronic Leak Detector (R134a compatible) (Example: Micro-Tech III, Robinair, Snap-on, or equivalent) Manifold and gauge set (R134a compatible) (Example: Robinair, Snap-on, or equivalent) 6. Consumable Materials Refrigerant: This system is to be charged with Dupont, or equivalent HFC R134a refrigerant only. Lubricant: This system is to be serviced with R134a compatible Polyester Refrigerant Oil. CAUTION Do not use Polyalkylene glycol (PAG) or Mineral Oil in this system. O-rings: As this system is charged with R134a refrigerant, it must be fitted with Highly Saturated Nitriles (HSN) O-rings. This system incorporates two different O-ring fittings, Torq-Lok and Insert. The HSN O-rings for the Torq-Lok fittings are BLACK in color and the HSN O-ring for the Insert fittings are GREEN in color.
AIR CONDITIONER SERVICE MANUAL A119-206M-1 Revision 12 Page 29 7. Suggested Spares List Item Part Number Effectivity Blower Motor – Fwd. Evaporator ES61064-1 Blower Motor – Aft Evaporator ES61142-1 Blower Assembly – Condenser A119-7008-1 Kit S/N 90 and subsequent S-6501EC-3 (alt.) Compressor Assembly A119-3040-1 Compressor Drive Belt ES35119-2 Receiver / Drier Bottle ES43030-5 Binary Switch ES57178-1 By-pass Valve ES26194-24 Blower Assembly – Condenser (Standard) ES73190-1 Kit S/N 28 thru 46 Blower Assembly – Condenser (High Output) ES73192-1 Kit S/N 47 thru 89 HSN O-rings; Insert type (Green) Size #6 O-ring ES44010-2 #8 O-ring ES44010-3 #10 O-ring ES44010-4 HSN O-rings; Torq-Lok Type (Black) Size #6 O-ring ES44012-2 #8 O-ring ES44012-3 #10 O-ring ES44012-4
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AIR CONDITIONER SERVICE MANUAL A119-206M-1 Revision 12 Page 31 CHAPTER 7 STANDARD PRACTICES AND INFORMATION 1. Fitting Torque Procedures and Values INSERT O-RING FITTINGS Torq Lok FITTINGS Apply a thin coating of refrigerant oil to O-ring and Female side of fitting. Confirm there is no damage (nicks, dirt, etc.) on fittings. Slide B-nut back away from the end of the tube so you can see the O-ring as you slide the fitting together. Be careful not to pinch O-ring during assembly. Engage the male end into the female fitting being careful to maintain alignment. The male flange should seat fully against the female fitting without the O-ring being pinched. It is important to hold the fitting together while sliding the B-nut forward and engaging the threads. Tighten the B-nut by hand and then torque as follows. # 6 Fittings: 30 – 35 in-lbs (3.4-4.0 Nm) # 8 Fittings: 40 – 45 in-lbs (4.6-5.1 Nm) #10 Fittings: 50 – 55 in-lbs (5.7-6.3 Nm) DO NOT OVER TORQUE ALWAYS USE BACK UP WRENCH INSERT O-RING FITTINGS Torq Lok FITTINGS Once the system is charged, check each fitting with an electronic leak detector. (An electronic leak detector is the only reliable method of checking for refrigerant leaks) Once the fittings have been checked and are found to be free of leaks, torque seal as appropriate.
AIR CONDITIONER SERVICE MANUAL A119-206M-1 Revision 12 Page 32 2. Removal and Replacement of Forward Evaporator Assembly (Figure 4-6) NOTE It will be necessary to evacuate (discharge) refrigerant from the system to remove or replace forward evaporator assembly. Instructions for servicing are found in Chapter 6. Removal a. Disconnect refrigerant plumbing from evaporator fittings once refrigerant is evacuated. Always use a back-up wrench. Cap open lines to prevent contamination. b. Remove flex duct coming from LH outlet and RH blower assembly by removing cable ties to evaporator. c. Disconnect drain line from bottom of evaporator by removing cable tie. d. Disconnect blower motor electrical connector. e. Remove attaching hardware securing evaporator assembly to support brackets. Remove evaporator. Replacement a. Install evaporator and secure with attaching hardware to support brackets. b. Connect blower motor electrical connector and secure as needed. c. Connect drain line at bottom of evaporator and secure with cable tie. d. Connect flex duct from LH outlet and RH blower assembly and secure with cable ties. e. Replace all O-rings before connecting refrigerant plumbing to evaporator fittings using a back-up wrench. Torque refrigerant line connections to 30–35 inch-lbs (3.4-4.0 Nm) for the #6 fitting and 40–45 inch-lbs (4.6-5.1 Nm) for the #8 fitting. f. Service air conditioning system with refrigerant. 3. Removal and Replacement of Forward Evaporator RH Blower Assembly (Figure 4-6) Removal a. Remove flex duct coming from RH outlet and evaporator assembly by removing cable ties at RH blower assembly. b. Disconnect blower motor electrical connector. c. Remove attaching hardware securing blower assembly to mounting bracket. Remove blower assembly. Replacement g. Install blower assembly and secure with attaching hardware to mounting bracket. h. Connect blower motor electrical connector and secure as needed. i. Connect flex duct from RH outlet and evaporator assembly and secure with cable ties.
AIR CONDITIONER SERVICE MANUAL A119-206M-1 Revision 12 Page 33 4. Removal and Replacement of Aft Evaporator Assembly (Figure 4-7) NOTE It will be necessary to evacuate (discharge) refrigerant from the system to remove or replace aft evaporator assembly. Instructions for servicing are found in Chapter 6. Removal a. Disconnect refrigerant plumbing from evaporator fittings once refrigerant is evacuated. Always use a back-up wrench. Cap open lines to prevent contamination. b. Remove attaching hardware and disconnect elbow duct from inlet of evaporator. Remove flex duct from outlet of evaporator by removing cable ties. c. Disconnect drain line from bottom of evaporator by removing cable tie. d. Disconnect wiring to temperature control module in the evaporator assembly by disconnecting electrical connector. e. Remove attaching hardware securing evaporator assembly to cabin top. Remove evaporator. Replacement j. Install evaporator and secure with attaching hardware to cabin top. k. Connect drain line at bottom of evaporator and secure with cable tie. l. Connect elbow duct and flex duct to inlet and outlet of evaporator and secure with cable ties. Seal elbow duct joint to evaporator with black RTV. m. Connect wiring to temperature control module in the evaporator assembly by connecting electrical connector. n. Replace all O-rings before connecting refrigerant plumbing to evaporator fittings using a back-up wrench. Torque refrigerant line connections to 30–35 inch-lbs (3.4-4.0 Nm) for the #6 fitting and 40–45 inch-lbs (4.6-5.1 Nm) for the #8 fitting. o. Service air conditioning system with refrigerant. 5. Removal and Replacement of Aft Evaporator Blower Assembly (Figure 4-7) Removal a. Remove flex duct coming from evaporator assembly by removing cable ties at blower assembly inlet. b. Remove attaching hardware securing blower assembly outlet to air box assembly. c. Disconnect blower motor electrical connector. d. Remove attaching hardware securing blower assembly to angle mounting brackets. Remove blower assembly. Replacement p. Install blower assembly and secure with attaching hardware to angle mounting brackets. q. Connect blower motor electrical connector and secure as needed.
AIR CONDITIONER SERVICE MANUAL A119-206M-1 Revision 12 Page 34 r. Connect air box assembly to blower outlet with attaching hardware. s. Connect flex duct from evaporator assembly and secure with cable ties. 6. Removal and Replacement of Air Box Assembly (Figure 4-7) Removal a. Remove fresh air flex duct coming from fresh air box by removing cable ties at air box assembly inlet. b. Remove attaching hardware securing air box assembly inlet to aft evaporator blower assembly outlet. c. Remove attaching hardware securing air box assembly to cabin top. Remove air box assembly. Replacement a. Install air box assembly and secure with attaching hardware to cabin top. b. Secure air box assembly to blower outlet with attaching hardware. c. Connect fresh air flex duct from fresh air box and secure with cable ties. 7. Removal and Replacement of Condenser Assembly (Figure 4-8) NOTE It will be necessary to evacuate (discharge) refrigerant from the system to remove or replace condenser assembly. Instructions for servicing are found in Chapter 6. Removal a. Remove screws that attach condenser blower assembly to the lower contour of the belly panel. This will allow the condenser blower assembly to pivot on the forward hinged support plate. b. Remove lower aft fairing to gain access to condenser assembly. c. Disconnect refrigerant plumbing from condenser fittings once refrigerant is evacuated. Always use a back-up wrench. Cap open lines to prevent contamination. d. Remove attaching hardware securing condenser assembly to side panels. Remove condenser. Replacement a. Install condenser and secure with attaching hardware to side panels. Safety wire bolts. Reseal areas around condenser with ES06022-2 cork tape to prevent air leakage. b. Replace all O-rings before connecting refrigerant plumbing to condenser fittings using a back-up wrench. Torque refrigerant line connections to 30–35 inch-lbs (3.4-4.0 Nm) for the #6 fitting and 40–45 inch-lbs (4.6-5.1 Nm) for the #8 fitting. c. Install lower aft fairing and install screws that attach condenser blower assembly to the lower contour of the belly panel. d. Service air conditioning system with refrigerant.