AirComm Corporation Airbus EC145 Cabin Air Conditioner Instructions for Continued Airworthiness User Manual

							AIR CONDITIONER SERVICE MANUAL EC145-200M-1 
 
Revision 13  Page 35 
 
CHAPTER 6 
STANDARD PRACTICES INFORMATION (continued) 
 
10. REMOVAL, INSTALLATION/ REPLACEMENT OF BY-PASS VALVE ASSEMBLY. 
 
REMOVAL 
 
A. Access refrigerant plumbing to By-pass Valve. 
 
B.  It will be necessary to evacuate (discharge) the refrigerant from the system to remove or replace 
the by-pass valve. Instructions for servicing of the system are found in Chapter 5 Servicing. 
 
CAUTION 
Refrigerant servicing should be performed by qualified personnel only! 
 
C. Remove safety wire and mounting screws that attaches support bracket to the valve coil assembly. 
 
D. Disconnect the electrical connector to the by-pass valve assembly. 
 
E. Disconnect the refrigerant lines from both sides of the by-pass valve assembly. 
 
CAUTION 
Always use a back up wrench when removing or installing refrigerant line fittings. 
 
F. Remove the by-pass valve. 
 
INSTALLATION / REPLACEMENT 
 
A.  Install the by-pass valve in the reverse order of the removal, and replace all O-rings,  
      (See page 6-1 for installation data / fitting assembly procedures). 
 
B. Recharge the refrigerant per the servicing instructions on Page 5-1, steps A through I. 
 
CAUTION 
Refrigerant servicing should be performed by qualified personnel only! 
 
 
 
 
 
 
 
 
 
 
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							AIR CONDITIONER SERVICE MANUAL EC145-200M-1 
 
Revision 13  Page 36 
 
CHAPTER 6 
STANDARD PRACTICES INFORMATION (continued)   
 
11. REMOVAL, INSTALLATION / REPLACEMENT OF AFT EVAPORATOR BLOWER MOTOR 
 
REMOVAL 
 
CAUTION 
It is recommended that the battery and external power be disconnected before starting work. 
 
A.  Access to the aft evaporator blower assemblies requires the removal of the overhead ceiling 
panel in the main cabin area. 
 
B.  Remove the hardware that attaches the blower motor to the Aft Evaporator housing. 
 
C.  Disconnect electrical connection to the Aft Evaporator Blower Assembly. 
 
D.  Remove Blower Assembly from aircraft. 
 
INSTALLATION / REPLACEMENT 
 
A.  The installation of the Aft Evaporator Blower Assembly is in the reverse order of their 
removal. 
 
 
 
 
 
 
 
 
 
 
 
 
 
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							AIR CONDITIONER SERVICE MANUAL EC145-200M-1 
 
Revision 13  Page 37 
 
CHAPTER 6 
STANDARD PRACTICES INFORMATION (continued) 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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							AIR CONDITIONER SERVICE MANUAL EC145-200M-1 
 
Revision 13  Page 38 
 
CHAPTER 7 
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  Solution 
System not Cooling 
(Evaporator blowers still operating) 
a.  System is low or empty of 
refrigerant. 
 
a.  Evacuate the system, determine 
the origin of the refrigerant leak, 
and re-charge the system as 
prescribed in chapter 5. 
 b. Moisture or air in the system.  b.  Evacuate the system, Replace the 
receiver / drier, and place the 
system under a vacuum for a 
minimum of 30 minutes before 
recharging the system. ¹ 
 c. Compressor   c. If the compressor has failed, it 
must be replaced, as shown in 
chapter 6. ¹ 
 d. Compressor drive belt  d. If the compressor drive belt has 
failed it will need to be replaced. 
Replace and adjust compressor 
drive belt as shown in chapter 6. ¹ 
 e. By-pass valve   e.  Check to insure the temperature 
control knob on the A/C control 
panel in the cockpit is in the full 
cold position, and the temperature 
control circuit breaker has not 
tripped. If the valve remains open 
(by-passing refrigerant) the valve 
will need replacement, as shown in 
chapter 6. ¹ 
 f. Condenser blower motor / fan(s) 
assembly. 
       
f.  Check to insure the condenser 
blower motor / fan assembly are 
receiving power, and the circuit 
breakers have not tripped. If the 
blowers still do not function, they 
may have failed internally and 
must be replaced as shown in 
chapter 6.   
 g. Condenser Blockage g. Check to insure the condenser fins 
are clear and free of any blockage, 
and this will cause higher than 
normal discharge pressure in the 
system. 
System not cooling 
(Evaporator blowers not operating) 
h.  Air conditioner control circuit 
breaker tripped. 
h.  Reset circuit breaker. If breaker 
will not reset, check for short in 
circuit. 
 i. Forward or Aft evaporator 
blower circuit breaker tripped. 
i.  Reset circuit breaker. If breaker 
will not reset, check for short in 
circuit. 
 
 
 
 
 
 
  
						

							AIR CONDITIONER SERVICE MANUAL EC145-200M-1 
 
Revision 13  Page 39 
 
 
CHAPTER 7 
TROUBLESHOOTING (continued) 
 
1. SYSTEM TROUBLESHOOTING (continued) 
 
Problem  Probable Cause  Solution 
System not cooling 
(Evaporator blowers not 
operating) 
j.  Forward and aft evaporator 
blower motor(s)   
 
     
j.  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, as 
shown in chapter 6. ¹ 
Loss of cooling limited to one 
evaporator. 
k.  Expansion valve malfunction.  k. If cooling is lost in only one of 
the evaporators, and the 
blowers continue to function, 
it is most likely a blockage at 
the expansion valve orifice. 
This is most often caused by 
dirt in the system forming a 
blockage as the refrigerant 
passes through the valve. 
Evacuating the system and 
changing the receiver drier 
should cure this problem. If 
the above actions do not 
resolve the problem, the 
evaporator assembly should 
be returned to Air Comm 
Corporation for repair. ¹ 
External moisture 
(Condensate) in the area of 
forward  / aft evaporator 
l.  Leak in evaporator, or 
evaporator drainage system. 
l.  If water is noted in the area 
near the evaporators. This is 
normally caused by a loose, 
cracked, plugged, or 
disconnected drain line.  
NOTE 
       The drain line consists of a 
tube which extends from the 
lower surface of the 
evaporators through the 
outer contour of the 
helicopter. 
(Contact Air Comm Corporation Service Department for current pricing and availability of 
replacement components and parts). 
 
 
 
 
 
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							AIR CONDITIONER SERVICE MANUAL EC145-200M-1 
 
Revision 13  Page 40 
 
 
CHAPTER 7 
TROUBLESHOOTING (continued) 
 
Figure 7-1 General Arrangement – Air Conditioning System Installation. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
						

							AIR CONDITIONER SERVICE MANUAL EC145-200M-1 
 
Revision 13  Page 41 
 
 
CHAPTER 7 
TROUBLESHOOTING (continued) 
 
Figure 7-2 Air Conditioning System Electrical Schematic  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
						

							AIR CONDITIONER SERVICE MANUAL EC145-200M-1 
 
Revision 13  Page 42 
(S/N 001 Thru 005) 
 
CHAPTER 7 
TROUBLESHOOTING (continued) 
Figure 7-3 Air Conditioning System Electrical Schematic  
 
 
 
 
 
 
 
 
 
 
(Cut and paste drawing) 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
						

							AIR CONDITIONER SERVICE MANUAL EC145-200M-1 
 
Revision 13  Page 43 
(S/N 006 thru 014) 
 
CHAPTER 7 
TROUBLESHOOTING (continued) 
 
Figure 7-4 Refrigerant Plumbing Schematic  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
						

							AIR CONDITIONER SERVICE MANUAL EC145-200M-1 
 
Revision 13  Page 44 
 
CHAPTER 7 
TROUBLESHOOTING (continued) 
 
 
 
 
 
 
 
Cut and paste 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Electrical Schematic with 3rd Aft Evaporator Blower 
(S/N 015 and Subsequent)