AirComm Corporation Airbus AS350 Air Conditioner Instructions for Continued Airworthiness User Manual

AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
Revision 6 Page 43 
 
d. Refer to Airbus Model AS350 Maintenance Manual for removal of main gearbox 
engine coupling to gain access to the hydraulic pump/compressor drive pulley on 
the main rotor input shaft. Remove drive belt. 
 
Replacement 
 
NOTE 
A  second  belt  should  be  pre-installed  on  the  main rotor  input  shaft 
housing as a spare. 
NOTE 
Flat  belts must  be  installed  so  that  the  direction  of  travel  conforms  to  the 
marking on the...

AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
Revision 6 Page 44 
 
12. Adjustment of Compressor Drive Belt 
 
NOTE 
Proper  static  belt  tension (and  alignment  for  Flat belt) is  necessary  to 
insure  proper  belt  life  and  to  avoid  excessive  side  load  on  the M/R  input 
shaft. The belt tension should be reset after several hours of operation for 
a new belt. 
 
a. Ensure compressor mount fasteners are tightened and properly torqued. 
b. Apply appropriate force as per Figures 7-5 or 7-6...

AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
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Figure 7-6 – Poly V Belt Adjustment Value 
 
Figure 7-7 – Flat Belt Alignment 
 
13. Removal and Replacement of Compressor Assembly 
(Figure 4-3 & 4-4) 
 
Removal 
 
a. Disconnect  refrigerant  plumbing  from  compressor fittings  once  refrigerant  is 
evacuated. Always use a back-up wrench. 
b. Cut safety wire on compressor belt tensioning link and belt tensioning link jam 
nuts, and loosen respective jam nut(s). 
c. Loosen upper and...

AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
Revision 6 Page 46 
or  old)  retains  .5  oz.  of  unrecoverable  oil  even  after  completely  draining. 
This  total  is  what  is  needed  to  be  in  the  new  compressor.  New 
compressors  come  from  Air  Comm  charged  with  8.0  oz.  of  oil.  This 
should be adjusted according to the amount of oil recovered from the old 
compressor and any other components being replaced. The receiver drier 
should always be replaced when the compressor is replaced...

AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
Revision 6 Page 47 
b. Replace all O-rings before connecting refrigerant plumbing to receiver drier bottle 
fittings  using  a  back-up  wrench.  Torque  refrigerant  line  connections per  section 
2, p.36. 
c. Service air conditioning system with refrigerant per Chapter 6, p.30. 
 
15. Removal and Replacement of Bypass Valve  
(Figure 4-15) 
 
Removal 
 
a. Disconnect refrigerant plumbing from bypass valve once refrigerant is evacuated. 
Always use a back-up...

AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
Revision 6 Page 48 
c. Remove the pressure relief valve. 
 
Replacement 
a. Place a small amount of refrigerant oil on the o-ring and install the valve. 
b. Re-charge the system per chapter 6, p.30. 
   

AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
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CHAPTER 8 
TROUBLESHOOTING 
1. System Troubleshooting 
 
Prior to troubleshooting a defective system, it is advisable to conduct a visual 
inspection for general condition and obvious signs of damage or failure. 
 
The following matrix lists the easiest checks and the most likely problems. 
 
Problem Probable Cause Corrective Action 
System not Cooling 
 
(Evaporator blowers still operating) 
System is low or empty of 
refrigerant...

AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
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Problem Probable Cause Corrective Action 
System not cooling 
(Evaporator blowers not operating) 
Forward and aft evaporator blower 
motor(s) 
Check for power to the motor(s), 
and for the free movement of the 
blower wheel; if the motor shaft 
does not turn smoothly the motor 
must be replaced 
Loss of cooling limited to one 
evaporator 
Expansion valve malfunction If cooling is lost in only one of the 
evaporators, and the blowers...

AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
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Figure 8-1 – Electrical Schematic, Side Baggage Mounted Condenser (Tail Boom Condenser Option identical except for additional condenser blower.) 
 
 
  
  

AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
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Figure 8-2 – Electrical Schematic, Relay Panel