AirComm Corporation Airbus EC120 Cabin Air Conditioner Instructions for Continued Airworthiness User Manual

							AIR CONDITIONER SERVICE MANUAL EC120-200M-1 
Revision 5 Page 41 
INSTALLATION / REPLACEMENT 
 
A. Locate the evaporator assembly on the transmission deck. Install and torque the (6) 
six AN3-3A mounting screws. 
 
B. Mate the molex connector. 
 
C. Make the refrigerant line connections and torque the fittings per the specifications on 
p.35. 
CAUTION 
Always use a backup wrench when removing or installing refrigerant line fittings. 
 
 
B. Recharge the refrigerant per the service instructions on Page 27.  
 
CAUTION 
Refrigerant servicing should be performed by qualified personnel only! 
 
 
7. 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 the roof area forward of the main transmission. 
 
B. Disconnect electrical connection to the Aft Evaporator Blower Assembly. 
 
C. Pry away the 5 spring clips that retain the blower housing halves together. 
 
D. Remove the 4 sets of motor attaching hardware and remove the motor. 
 
 
 
INSTALLATION / REPLACEMENT 
 
A. Locate the replacement blower on the outboard blower housing shell and install the 4 
sets of attaching hardware.  
 
B. Locate the motor/housing assembly onto the inboard blower housing on the aircraft. 
Re-install the 5 spring clips. 
 
C. Mate the blower electrical connection. 
 
  
						

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8. Removal, installation / replacement of the condenser scoop assembly 
 
 
REMOVAL 
 
CAUTION 
It is recommended that the battery and external power be disconnected before starting work. 
 
A. Remove the AN3-3A screws that attach the EC120-7007-1 Condenser Scoop Assembly to 
the lower contour of the belly panel. This will allow the Condenser Scoop Assembly to pivot 
on the forward hinged support plate. 
 
CAUTION 
Be sure to support this assembly when removing the attaching hardware to prevent damage to 
the Condenser Scoop Assembly, or the aircraft. 
 
B. Remove the AN525-10R Screws that attach the forward hinge support plate to the aircraft 
belly panel. 
 
C. Disconnect the Molex Connector that attaches the power wires from the Condenser Scoop 
Assembly to the aircraft wiring, and remove the EC120-7007-1 Condenser Scoop Assembly 
from the aircraft. 
 
 
 
INSTALLATION / REPLACEMENT 
 
A. Locate the Condenser Scoop Assembly and install the AN525-10R screws to attach the 
forward hinge support plate to the aircraft belly panel.  
 
B. Mate the blower Molex connector. 
 
C. Rotate the assembly into position and install the AN3-3A screws. 
 
NOTE 
Perform a maintenance operational check of the Condenser Scoop Assembly on completion of 
the installation, to insure that there is no rubbing or binding of the Scoop Door. 
 
NOTE 
The Condenser Scoop Door is rigged at the factory with a .20 to .40 inch gap between the 
Scoop Door and the Scoop Plate assemblies with the Scoop Door in the full up position. 
 
CAUTION 
Do not attempt to disassemble or readjust the Scoop Door, as altering the rigging may damage 
the Scoop Door Bellcrank, or Scoop Door Actuator. 
  
						

							AIR CONDITIONER SERVICE MANUAL EC120-200M-1 
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9. Removal, Installation / Replacement of Condenser Assembly with 
deployable scoop 
 
REMOVAL 
 
A. Remove the Condenser Scoop Assembly EC120-7007-1 per section 8, p.42. 
 
B. Discharge the refrigerant from the system. Instructions for servicing the system are 
found in Chapter 6 Servicing. 
 
CAUTION 
Refrigerant servicing should be performed by qualified personnel only! 
 
CAUTION 
It is recommended that the battery and external power be disconnected before starting work. 
 
 
C. Disconnect the Condenser Assembly from the refrigerant lines that attach to the 
condenser assembly. 
 
CAUTION 
Always use a backup wrench when removing or installing refrigerant line fittings. 
 
D. Remove the AN3-3A bolts that attach the Condenser to the belly of the aircraft, and 
remove the Condenser Assembly by sliding it inboard and out through the opening. 
 
INSTALLATION / REPLACEMENT 
 
A. Locate the condenser assemblies and install the AN3-3A attachment screws.  
 
B. Replace all O-rings and secure refrigerant lines per tightening specifications on p.35. 
 
B. Recharge the refrigerant per the servicing instructions on Page 27. 
 
CAUTION 
Refrigerant servicing should be performed by qualified personnel only! 
 
CAUTION 
Always use a backup wrench when removing or installing refrigerant line fittings. 
 
NOTE 
There should be no air leakage around the condenser assembly other than inlet and outlet. 
Seal all other openings, including those around the Condenser Refrigerant tubes. 
 
 
  
						

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10.  Removal, Installation / Replacement of Condenser Assembly with fixed 
Grille Intake 
 
REMOVAL 
 
A. Remove the Outlet Screen EC120-7012-1. 
 
B. Discharge the refrigerant from the system. Instructions for servicing the system are 
found in Chapter 6 Servicing. 
 
CAUTION 
Refrigerant servicing should be performed by qualified personnel only! 
 
CAUTION 
It is recommended that the battery and external power be disconnected before starting work. 
 
CAUTION 
Be sure to support the blower assembly when removing the attaching hardware to prevent 
damage to the condenser housing, blower assembly, or the aircraft. 
 
C. Disconnect the refrigerant lines from the Condenser Assembly. 
 
CAUTION 
Always use a backup wrench when removing or installing refrigerant line fittings. 
 
D. Remove the AN3-3A bolts that attach the Condenser to the belly of the aircraft and 
remove the Condenser Assembly by sliding it out through the opening. 
 
INSTALLATION / REPLACEMENT 
 
A. Locate the condenser assembly and install the AN3-3A attachment screws. 
 
B. Replace all O-rings and secure refrigerant lines per tightening specifications on p.35. 
  
C.  Recharge the refrigerant per the servicing instructions on Page 27. 
 
CAUTION 
Refrigerant servicing should be performed by qualified personnel only! 
 
CAUTION 
Always use a backup wrench when removing or installing refrigerant line fittings. 
 
NOTE 
There should be no air leakage around the condenser assembly other than inlet and outlet. 
Seal all other openings, including those around the Condenser Refrigerant tubes. 
 
  
						

							AIR CONDITIONER SERVICE MANUAL EC120-200M-1 
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11. Removal and replacement of condenser blower motor & fan assembly for 
deployable air scoop configuration 
 
REMOVAL 
CAUTION 
It is recommended that the battery and external power be disconnected before starting work. 
 
A. Remove the AN3-3A Bolts that attach the EC120-7007-1 Blower assembly to the 
lower contour of the belly panel. This will allow the condenser scoop assembly to 
pivot on the forward hinged support plate. 
 
CAUTION 
Be sure to support the blower assembly when removing the attaching hardware to prevent 
damage to the condenser housing, blower assembly, or the aircraft. 
 
B. Remove safety wire that secures the (4) AN3H-3A bolts (2) two on each side that 
attach the ES73186-1 Blower motor & Fan assembly to the condenser scoop 
assembly, and remove bolts. 
 
C. Disconnect the ES73186-1 Blower motor & Fan assembly at the Molex connector. 
 
D. Once the mounting bolts have been removed, the blower can be removed. 
 
REPLACEMENT  
 
A. Locate the replacement blower assembly onto the condenser scoop assembly and 
secure with the mounting hardware and safety wiring. 
 
B. Reconnect the Molex connector. 
 
C. Reinstall the AN3-3A bolts that secure the EC120-7007-1 Blower assembly to the 
lower contour of the belly panel. 
 
D. Apply power, and operate the Air conditioner by placing the control switch in the A/C 
position several times to insure there is no binding and for proper operation of the 
Blower motor & Fan assembly. 
 
12. Removal, Installation / Replacement of Receiver Drier Bottle 
 
REMOVAL 
 
 A. Access refrigerant plumbing to the Receiver Drier Bottle. 
 
B. Discharge the refrigerant from the system. Instructions for servicing the system are 
found in Chapter 6 Servicing.  
						

							AIR CONDITIONER SERVICE MANUAL EC120-200M-1 
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CAUTION 
Refrigerant servicing should be performed by qualified personnel only! 
 
C. Disconnect refrigerant lines from both sides of the receiver drier connection fittings. 
 
CAUTION 
Always use a backup wrench when removing or installing refrigerant line fittings. 
 
D. Loosen the retaining clamp holding the receiver drier bottle to the support bracket. 
 
E. Remove the receiver drier bottle. 
 
INSTALLATION / REPLACEMENT 
 
A. Locate the receiver drier bottle and secure it with the retaining clamp. 
 
B. Replace the o-rings on the refrigerant lines and secure the lines to the bottle per the 
tightening instructions on p. 35. 
 
 C. Recharge the refrigerant per the servicing instructions on Page 27. 
 
NOTE 
Never reuse a receiver drier bottle Keep new receiver drier bottles capped until just prior to 
their installation. 
 
CAUTION 
Refrigerant servicing should be performed by qualified personnel only! 
 
CAUTION 
Always use a backup wrench when removing or installing refrigerant line fittings. 
 
13. Removal, Installation / Replacement of Binary Switch 
 
REMOVAL 
 
A. Access the Binary Switch adjacent to the receiver-drier bottle near the condenser 
assembly. 
 
 B. Disconnect electrical connectors from bottom of binary switch. 
 
C. Unscrew switch from the Schrader valve located on outlet tube from the receiver drier 
bottle. Remove switch. Note that it is not necessary to discharge the refrigerant for 
this servicing operation. 
 
NOTE 
Use the flats provided on the top of the switch body to tighten, do not attempt to tighten, or 
loosen the pressure switch by hand.  
						

							AIR CONDITIONER SERVICE MANUAL EC120-200M-1 
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INSTALLATION / REPLACEMENT 
 
A. Install the binary pressure switch on the Schrader valve and tighten. 
 
B. Mate the electrical connector to the switch. 
 
 
 
14.  Removal, Installation/ Replacement of By-Pass Valve Assembly 
 
REMOVAL 
 
A. Access the By-pass Valve. Refer to plumbing schematics Figures 8.9 & 8.10. The 
valve is located near the Aft Evaporator on the transmission deck. 
 
B. Discharge the refrigerant from the system. Instructions for servicing the system are 
found in Chapter 6 Servicing. 
 
CAUTION 
Refrigerant servicing should be performed by qualified personnel only! 
 
 
 C. Disconnect the electrical connector to the by-pass valve assembly. 
 
 D. Disconnect the refrigerant lines from both sides of the by-pass valve assembly. 
 
E. Remove safety wire and mounting screws that attaches the support bracket to the 
valve coil assembly. 
   
CAUTION 
Always use a backup wrench when removing or installing refrigerant line fittings. 
 
 F. Remove the by-pass valve. 
 
 
INSTALLATION / REPLACEMENT 
 
A. Mount the by-pass valve onto the support bracket. 
 
B. Install new o-rings and secure the refrigerant lines to the valve. Tighten the fittings per 
the tightening instructions on p.35 
 
C. Mate the electrical connector. 
 
D. Recharge the refrigerant per the servicing instructions on Page 27, steps A through I. 
 
CAUTION 
Refrigerant servicing should be performed by qualified personnel only!  
						

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							AIR CONDITIONER SERVICE MANUAL EC120-200M-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 
 
Evacuate the system, determine the 
origin of the refrigerant leak if 
applicable, and re-charge the system. 
 Moisture or air in the system Evacuate the system, replace the 
receiver drier, and place the system 
under a vacuum for a minimum of 30 
minutes before recharging the system. 
 Compressor If the compressor has failed, it must be 
replaced. 
 Compressor drive belt If the compressor drive belt has failed it 
will need to be replaced and adjusted. 
 By-pass valve 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. 
 Condenser blower motor / fan 
assembly 
Check to insure the condenser blower 
motor/fan assembly are receiving 
power, and the circuit breaker has not 
tripped; if the blowers still do not 
function, they may have failed internally 
and must be replaced. 
 Condenser Blockage Check to insure the condenser fins are 
clear and free of any blockage. This will 
cause higher than normal discharge 
pressure in the system. 
System not cooling 
 
(Evaporator blowers not operating) 
Air conditioner control circuit 
breaker tripped 
Reset circuit breaker; if breaker will not 
reset, check for short in circuit. 
 Forward or Aft evaporator blower 
circuit breaker tripped 
Reset circuit breaker; if breaker will not 
reset, check for short in circuit. 
  
						

							AIR CONDITIONER SERVICE MANUAL EC120-200M-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 
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 must be 
replaced. 
External moisture (Condensate) in 
the area of forward / aft evaporator 
Leak in evaporator, or evaporator 
drainage system 
 
 
 
 
 
 
 
 
The suction or low side of the 
evaporator refrigerant plumbing 
may be cold and will condense 
moisture. 
Water noted in the area near the 
evaporator is normally caused by a 
loose, cracked, plugged, or 
disconnected drain line. To test, 
pour water into the face of the 
evaporator checking for proper 
drainage and note any leaks. 
NOTE 
The drain line consists of a tube 
which extends from the lower 
surface of the evaporators through 
the outer contour of the helicopter. 
 
Cover line with a layer of insulating 
cork tape. 
(Contact Air Comm Corporation Service Department for current pricing and availability of 
replacement components and parts)