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

							AIR CONDITIONER SERVICE MANUAL EC120-200M-1 
Revision 5 Page 31 
When  reclaiming  refrigerant,  be  sure  to  measure  and  note  any  oil that  is  removed  from 
the  system.  If  a  measurement  is  not  available  use  1.5  oz.  as  the  estimated  loss.  
Replace  any  lost  oil  before  or  during  re-servicing.  Reduced  compressor  life  will  result  if 
the total system oil charge is not maintained. 
 
Make  note  of  any  oil  lost  due  to  spillage  or  leaks  during  time  of  installation  or 
maintenance. This oil must be replaced before the air conditioner is returned to service. 
 
The  following  chart  may  be  used  to  calculate  the  amount  of  oil  to  be  added  in  case  a 
component  is being  replaced  with  a  new  part. The  additional  oil  must  be  added  to  the 
compressor discharge (RED) line prior to charging. 
 
CAUTION 
Never add oil to the suction (BLUE) side of the system. 
 
 
Component Oil Amount 
Compressor See Instructions this 
section 
Evaporator 1.0 oz. per evaporator 
Condenser 1.5 oz. 
Receiver Drier 1.5 oz. 
Hose - Vapor 1.0 oz. per 10 foot 
Hose – Liquid 1.0 oz. per 20 foot 
 
 
C. Compressor  Replacement – To  properly  calculate  the  amount  of  oil  required  in  the 
replacement compressor, it is necessary to pour the oil out of the old compressor into a 
clean container. Drain the oil out of the fill plug hole and then pour oil out of the suction 
and  discharge  ports  while  rotating  the center  shaft  clockwise.  Measure  the  total  amount 
of oil removed from the old compressor. Add ½ oz. to the total measured to account for 
unrecoverable  oil  in  the  old  compressor.  This  total  is  what  is  needed  in  the  new 
compressor.  New  compressors  come from  Air  Comm charged  with  8  oz.  (240  cc)  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 or when the system has been open for an 
appreciable time, which accounts for another 1.5 oz. of oil that should be added. 
 
D. Below is an example of a compressor and receiver drier replacement for illustration: 
 
Draining  the  old  compressor  recovered  2.0  oz.  of  oil.  Adding  0.5  oz.  of  residual 
unrecoverable oil in the compressor gives 2.5 oz. The new receiver/drier requires 
an  additional  1.5  oz.,  plus  1.5  oz.  lost  when  the  refrigerant  was  evacuated  from 
the  system.  So  the  total  oil  needed  in  the  replacement  compressor  for  this  case 
is  5.5  oz.  Since  the  new  compressor  comes  with  8  oz.  of  oil,  remove  the  oil  fill 
plug and pour out 2.5 oz. of oil. 
 
  
						

							AIR CONDITIONER SERVICE MANUAL EC120-200M-1 
Revision 5 Page 32 
5. System Leak Check 
 
A. It is important to identify and eliminate refrigerant leaks at system connections to ensure 
trouble free operation of the air conditioning system. 
 
A new or empty system can be pressurized with R134a at 50 psi (3.5 kg-cm) to conduct 
a  leak  survey. Do  not  pressurize  the  system  with  compressed  air. Compressed  air  will 
introduce moisture into the system, which will degrade the operation of the system. 
 
The  preferred  method  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.  In  some  cases,  leaking  refrigerant  gas 
may collect in low areas of the aircraft 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. 
 
B. 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 refrigerant and install a new O-
Ring. 
 
NOTE 
Be  sure  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. 
 
 
6. 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) 
 
7. Consumable Materials 
 
A. Refrigerant:  This  system  is  to  be  charged  with  Dupont (or  equivalent) HFC  R134a 
refrigerant.  
						

							AIR CONDITIONER SERVICE MANUAL EC120-200M-1 
Revision 5 Page 33 
 
B. Lubricant: This  system  may  be  serviced  with  either  Polyolester  (POE)  or  Double  End 
Capped Polyalkylene Glycol (DEC PAG). 
 
C. O-Rings: This  system  utilizes  the  refrigerant  HFC  R134a.  Consequently,  the  system 
must  also  utilize  Highly  Saturated  Nitrile  (HSN O-Rings)  the  insert O-Ring fittings  (as 
previously  described  in  this  manual)  require  the  use  of  Green  HSN O-Rings  while  the 
TORQ  LOK®  Fittings  (As  previously  described  in  this  manual) require  the  use  of  the 
Black HSN O-Rings. 
 
D. Loctite thread sealer 554 (or equivalent). 
 
E. Torque-Seal Anti Sabotage Lacquer.  
						

							AIR CONDITIONER SERVICE MANUAL EC120-200M-1 
Revision 5 Page 34 
 
8. Suggested Spares List 
 
Item                    Part Number 
 
Blower Motor – Aft & Forward Evaporator [all models]                ES61072-1 
 
Blower Motor – Condenser, pre-Aug 2014 [deployable scoop intake]               ES61136-1 
Blower Motor – Condenser, post-Aug 2014 [fixed grille]                                    ES61082-3 
 
Compressor Assembly             EC120-3010-1  
 
Compressor Drive Belt                     7335 
 
Receiver / Drier Bottle               ES43030-5  
 
Binary Switch               ES57010-1 
   
By-pass Valve               ES26112-4 
 
Condenser Blower replacement, pre-Aug 2014 [deployable scoop]                  ES73186-1 
Condenser Blower replacement, post-Aug 2014 [fixed grille]                            S-6063EC-2 
 
Pressure Relief Valve [post-Aug 2014 models only]                                          ES49035-1                                       
 
 
 
HSN O-rings; Insert type (Green)      
Size  
#6 O-ring              AIR 440-840  
#8 O-ring              AIR 440-841  
#10 O-ring                              AIR 440-842 
 
HSN O-rings; Torq-Lok Type (Black) 
Size 
#6 O-ring             2-012-N1173 
#8 O-ring             2-014-N1173 
#10 O-ring             2-016-N1173 
  
						

							AIR CONDITIONER SERVICE MANUAL EC120-200M-1 
Revision 5 Page 35 
CHAPTER 7 
STANDARD PRACTICES AND INFORMATION 
1. Fitting Torque Procedures and Values 
 
INSERT O-RING FITTINGS    TORK-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: 
 
Tightening specifications 
CAUTION: ALWAYS USE BACK UP WRENCH. EXCESSIVE TORQUE WILL DAMAGE 
THE JOINT, COMPROMISING THE INTEGRITY OF THE SEAL. 
 
Insert O-Ring Fittings (regardless of size): Hand tighten, then turn an additional 60 deg. (one 
flat on the nut). 
 
TORQ-LOK ® fittings (regardless of size): Hand tighten, then turn an additional 30 deg. 
 
 
INSERT O-RING FITTINGS    TORK-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.  
						

							AIR CONDITIONER SERVICE MANUAL EC120-200M-1 
Revision 5 Page 36 
Once  the  fittings  have  been  checked  and  are  found  to  be  free  of  leaks,  torque  seal  as 
appropriate. 
 
 
2. Removal, Replacement & Adjustment of Compressor Drive Belt 
 
REMOVAL 
 
 A. It is necessary to access the transmission compartment to remove, replace, or adjust 
the Compressor Drive Belt. 
 
B. Cut safety wire on the Compressor Belt Tensioning Link and the Belt Tensioning link 
Jam Nuts, and loosen the respective Jam Nut(s). 
 
C. Before attempting to adjust the drive belt tension, insure that the compressor 
mounting / attaching bolts have been loosened, to allow free movement of the 
compressor body on the compressor mount. 
 
D. Remove the Compressor Drive Pulley in accordance with the instructions given in 
paragraph 4. “Removal, Installation / Replacement of Compressor Drive Pulley” of this 
manual. 
 
E. Adjust the Belt Tension Link to loosen the belt, and remove belt from the compressor 
& drive pulley. 
 
 
REPLACEMENT 
 
A. Install the drive belt on the compressor & drive pulleys. 
 
B. Replace the Compressor Drive Pulley in accordance with the instructions given in 
paragraph 4. Removal, Installation / Replacement of Compressor Drive Pulley of this 
manual. 
 
C. Adjust belt tension (See Adjustment below). 
 
D. Tighten the Belt Tensioning Link Jam Nuts and re-safety using .032 safety wire. 
 
E. Re-torque the Compressor Mounting / Attaching bolts to 80 to 100 inch lbs. (9.04 – 
11.30 Nm). 
 
NOTE 
Care should be taken to insure that the new belt is not damaged (nicked or cut) during 
installation.  
						

							AIR CONDITIONER SERVICE MANUAL EC120-200M-1 
Revision 5 Page 37 
 
ADJUSTMENT 
 
NOTE 
Proper belt tension is important to insure a long belt service life and to avoid excessive 
loads on the compressor, and bearing assemblies. 
 
A. The correct belt tension for the belt is 2.6 lbs. (1.2 kg.) This can be achieved with the 
aid of a belt tensioning tool (Kent-Moore® BT-33-73F Belt Tension Gauge or 
Equivalent). 
(This is the preferred method of obtaining proper belt tensioning). 
 
B. An alternate method is to observe a .2” (5 mm) belt deflection when 2.6 lbs (1.2 kg.) 
of force is applied at the midpoint of the belt.  
 
 
 
 
Tail rotor drive shaft pulley 
 
 
         Compressor drive pulley 
 
                         
 
 
 
 
NOTE 
The belt tension should be checked, and re-adjusted, if necessary after the first two hours of 
operation for a newly installed belt. 
 
3. Removal, installation / replacement of compressor assembly 
 
REMOVAL 
 
A. See Removal, Replacement, & Adjustment of Compressor Drive Belt prior to the 
removal of the air conditioner compressor assembly.  
 
B. It will be necessary to evacuate (discharge) the refrigerant from the system to remove 
and replace the air conditioner compressor. Instructions for servicing of the system 
are found in Chapter 6, p.27 of this manual. 
 
CAUTION 
Refrigeration servicing should be performed by qualified personnel only! 
 
C. Disconnect the refrigerant hoses from the suction and discharge ports located on the 
aft end of the compressor housing. 
 
Apply 2.6 lbs (1.2 kg) at midpoint 
 
Deflection should be .2” ER mmF  
						

							AIR CONDITIONER SERVICE MANUAL EC120-200M-1 
Revision 5 Page 38 
D. Remove the attaching hardware from the top of the belt tensioning link and the 
compressor mount assembly. Remove the mounting bolt that attach the compressor 
body to the top of the compressor mount, and remove compressor assembly. 
 
CAUTION 
Before removing the compressor attaching hardware it is necessary to seek assistance in 
supporting the compressor, due to the weight and position of this component. Failure to do 
so may result in damage to the aircraft. 
 
INSTALLATION / REPLACEMENT 
 
A. Locate the compressor on its mount. Torque attaching hardware to 80 to 100 inch lbs 
(9.04 – 11.30 Nm).  
 
B. Replace the O-rings on the refrigerant hoses, and re-connect the hoses to the 
compressor housing. Torque the fittings per the specifications on p.35. 
 
C. Re-install the belt tension link attaching hardware to the compressor, and torque to 95 
– 110 inch lbs (10.9-12.6 Nm).  
    
 D. Adjust the belt adjustment per the procedure shown on page 36  
 
 E. Recharge the refrigerant per the servicing instructions on page 27. 
 
CAUTION 
Refrigeration servicing should be performed by qualified personnel only! 
 
NOTE 
An electronic leak detector should be used any time a component is replaced or the system has 
been opened, to insure trouble free operation of the air conditioner system. 
 
 
4. Removal, installation / replacement of compressor drive pulley 
 
REMOVAL 
 
A. See Removal, Replacement & Adjustment of Compressor Drive Belt (page 36) prior 
to the removal of the air conditioner tail rotor driveshaft compressor drive pulley. 
 
See Removal, Installation / Replacement of Compressor Assembly (page 37) prior to 
the removal of the air conditioner tail rotor driveshaft compressor drive pulley. 
 
B. Remove the (2) two NASM21262-44 retaining bolts forward of the compressor drive 
pulley installation. 
 
CAUTION 
Insure that the drive pulley assembly is supported prior to the removal of the retaining bolts to 
prevent damage to the driveshaft, and the driveshaft coupling. 
 
  
						

							AIR CONDITIONER SERVICE MANUAL EC120-200M-1 
Revision 5 Page 39 
C. Remove the (6) six NASM21262-29 Bolts that retain the EC120-3500-1 Drive Pulley 
to the tail rotor driveshaft. 
 
 
CAUTION 
During the removal of the Compressor Drive Pulley, care should be taken not to damage the 
driveshaft, or other drive train components. 
 
 
 
INSTALLATION / REPLACEMENT 
 
A. Install the Compressor Drive Pulley EC120-3500-1 on the tail rotor Driveshaft, by 
placing the pulley tightly against the face of the tail rotor driveshaft spline. 
 
CAUTION 
As the driveshaft will need to be held during the installation of the Compressor Drive Pulley, 
care should be taken not to damage the driveshaft, or other drive train components. 
 
B. Reinstall retaining hardware and torque nuts to 50 to 70 Inch Lbs (5.7 – 10.0 Nm) 
 
 
5. Removal, installation / replacement of forward evaporator assembly 
 
REMOVAL 
 
A. It will be necessary to evacuate (discharge) the refrigerant from the system to remove 
or replace the forward evaporator assembly. Instructions for servicing of the system 
are found in Chapter 6, p.27. 
CAUTION 
Refrigerant servicing should be performed by qualified personnel only! 
 
B. Remove attaching hardware (AN3-5A Bolts) (4) four places in mounting brackets on 
aft of evaporator assembly. 
 
C. Disconnect the ducting that attaches the forward evaporator to the forward blower 
outlets. 
 
D. Disconnect the electrical connector from the forward evaporator assembly. 
 
E. Disconnect drain line from bottom of evaporator housing. 
 
F. Disconnect refrigerant plumbing from fittings and hoses located under the evaporator 
assembly area.  
 
CAUTION 
Always use a backup wrench when removing, or installing refrigerant line fittings.  
						

							AIR CONDITIONER SERVICE MANUAL EC120-200M-1 
Revision 5 Page 40 
 
 
INSTALLATION / REPLACEMENT 
 
A. Locate the evaporator assembly into its mounting location. Install the mounting 
hardware through the 4 mounting brackets and tighten. 
 
B. Install the ducting, drain line, and electrical connections. 
 
C. Replace all fitting o-rings and torque the refrigerant line connections per the 
specifications on p.35  
CAUTION 
Always use a backup wrench when removing, or installing refrigerant line fittings. 
 
 D. Recharge the refrigerant per the servicing instructions on Page 27. 
 
CAUTION 
Refrigerant servicing should be performed by qualified personnel only! 
 
NOTE 
 
An electronic leak detector should be used any time a component is replaced or the system has 
been opened, to insure trouble free operation of the air conditioner system. 
 
 
6. Removal, Installation / Replacement of Aft Evaporator Assembly 
 
REMOVAL 
 
A. Remove the forward transmission cowling. 
 
B. Remove the (6) six AN3-3A screws that retain the Aft Evaporator to the cabin roof. 
 
C. It will be necessary to evacuate (discharge) the refrigerant from the system to remove 
or replace the aft evaporator assembly. Instructions for servicing of the system are 
found in Chapter 6, p.27. 
 
D. Disconnect the refrigerant lines at the fittings to the evaporator housing. 
 
CAUTION 
Refrigerant servicing should be performed by qualified personnel only! 
 
CAUTION 
Always use a backup wrench when removing or installing refrigerant line fittings. 
 
E. Disconnect wiring to Temperature control module on the Aft Evaporator assembly by 
disconnecting the Molex connector.