AirComm Corporation Airbus EC135 Cabin Air Conditioner Instructions for Continued Airworthiness User Manual

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
Revision 8 Page 25 
 
SYSTEM DESCRIPTION REFRIGERANT CHARGE OIL CHARGE 
EC135 Air Conditioner system 
Single Fwd Evaporator 
 
3.8 lbs 
 
1.73 Kg 
 
8.0 oz. 
 
238 ml 
EC135 Air Conditioner system 
Dual Fwd Evaporator 
 
4.0 lbs  
 
1.82 Kg  
 
 8.0 oz. 
 
238 ml 
 
3. Lubrication Information 
CAUTION 
This system is serviced with either Polyester Based Refrigerant Oil (POE) or Double 
end capped Polyalkylene oil (DEC PAG, aka Ultra PAG). The use of Mineral Oil or 
Polyalkylene (PAG) in this system will cause damage to the air conditioner 
compressor and expansion valves. 
 
A. The  total  system  oil  charge  is  8.0  fl  oz.  (238  ml.)  of  Double  End  Capped 
Polyalkylene  Glycol  (DEC  PAG).  The  oil  is  initially  contained  within  the 
compressor  as  shipped  from  the  factory  so  no  additional  oil  is  required  when 
installing a new system. 
 
B. 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. 
 
C. 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. 
 
D. The Service Ports for this system are located in the upper aft right-hand corner of 
the baggage compartment adjacent to the condenser assembly (Figure 13). 
 
  
E. This system may be serviced with either Polyolester (POE) or Double End 
Capped Polyalkylene Glycol (DEC PAG).  Polyalkylene Glycol is preferred due to 
its superior lubricating properties and improved compressor service life.  There 
are several types of PAG available. Only the “Double End Capped” type is 
permissible in Air Comm Corporation air conditioning systems.  Double End 
Capped PAG oil is available from Air Comm Corporation in 8 ounce bottles (P/N 
ES94006-13).  Mixing of POE and PAG is acceptable.  Disregard previous 
statements to the contrary. They referenced PAG oil that was not “Double End 
Capped”.  Current versions of compressors are designed to be operated using 
PAG oil.  Testing by Air Comm Corporation has shown that “Double End  
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
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Capped” PAG is compatible with POE and can therefore be mixed. “Double End 
Capped” is a reference to the chemical structure of the molecule and not to the 
container. 
 
Do not use Mineral oil in this system with R134a refrigerant. Do not use any 
refrigerant oil other than Double End Capped Polyalkylene Glycol (also known as 
“ULTRA PAG”) or Polyolester (also POE). 
 
Containers of DEC PAG or POE will absorb moisture if left open (hygroscopic). 
Keep containers tightly capped when not in use and keep all system components 
capped while servicing system. 
 
The quantity of lubrication in the system is critical. If too little lubrication is in the 
system the compressor life may be reduced. No other component in the A/C 
system requires lubrication. Too much lubricant in the system will retard heat 
transfer in the evaporator and condenser coils and reduce the cooling capacity of 
the system.  
 
F. 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.  
 
Component Oil Amount 
Compressor See Instructions  
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 
 
 
4. 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  kgcm)  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  
						

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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. 
 
 
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 
 
A. 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. 
 
B. Loctite thread sealer 554 (or equivalent). 
 
C. Torque-Seal Anti Sabotage Lacquer. 
   
						

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7. Suggested Spares List 
 
 
 ITEM  PART NUMBER 
 
Blower Motor – Aft Evaporator ES61142-3 
 
Blower Motor – Forward Evaporator ES61064-1 
 
Compressor Assembly         EC135-3040-1 
 
Compressor Drive Belt ES35135-1 
 
Receiver / Drier Bottle ES43030-6 
 
Binary Switch ES57178-1 
 
By-pass Valve ES26194-24 
 
Condenser Blower ES73186-9 
 
Compressor Drive Bearings ES33100-3 
 
 HSN O-Rings; Insert Type (Green) 
 # 6 O-Ring ES44010-2 
 # 8 O-Ring ES44010-3 
 # 10 O-Ring ES44010-4 
 
 HSN O-Rings; TORQ LOK® Type (Black) 
 #6 O-Ring ES44012-2 
 #8 O-Ring ES44012-3 
 #10 O-Ring ES44012-4 
 
  
						

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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: 
a. TORQ LOK® Fittings: Must be hand snug (metal to metal) and then add 
an additional 30 degrees (one half flat). 
b. Insert O-Ring Fittings: Must be hand snug against O-ring, and then an 
additional 60 degrees (one flat). 
 
CAUTION: 
Excessive torque will damage fitting. 
DO NOT OVER TORQUE 
ALWAYS USE BACK UP WRENCH 
 
INSERT O-RING FITTINGS    TORQ-LOK® FITTINGS 
 
 
   
						

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2. Torque Seal. 
 
Once system is charged, check each fitting with an electronic leak detector.  Once 
fittings have been checked and are leak free, torque Seal as appropriate. 
 
3. General Information 
 
A. Refer  to Airbus Model  EC135  Maintenance  Manual  for  general  removal  and 
installation  procedures  associated  with  basic  aircraft  equipment  and 
components. 
B. Prepare  helicopter  for  maintenance.  Disconnect  battery  and/or  electrical 
power supply. 
C. It  may  be  necessary  to  evacuate  (discharge)  refrigerant  from  the  system  to 
remove  or replace  certain components.  Instructions for servicing  are  found  in 
CHAPTER 7. 
D. All  openings  and  ports  in  components,  hoses,  and  tubes  disconnected  or 
removed to facilitate removal and replacement procedures must be capped or 
plugged to prevent contamination. 
E. Retain  all  parts  and  attaching  hardware  for  reassembly,  unless  otherwise 
noted. 
F. Always  use  a  back-up  wrench on  lines  and  fittings when  removing  and 
installing refrigerant plumbing. 
G. Perform functional checks  and/or  ground  runs  to  verify  component/system 
operation. 
 
4. Removal and Replacement of Forward Evaporator Assembly (LH or RH) 
(Figure 8 and Figure 9) 
 
Removal 
 
A. Discharge refrigerant. See Chapter 6 Servicing for instructions. 
B. Disconnect  refrigerant  plumbing  from  evaporator  tube  and  fittings  once 
refrigerant is evacuated. 
C. Remove  outlet  flex  duct  from  the outlet  adapter on  evaporator  by  removing 
cable ties. 
D. Disconnect drain line from bottom of evaporator by removing cable tie. 
E. Disconnect blower motor electrical connector. 
F. Remove  attaching  hardware  securing  evaporator  assembly  to mounting 
brackets and supports. 
G. Remove forward evaporator assembly. 
 
Installation/Replacement 
 
A. Install  forward  evaporator  assembly  and  secure  with retained  attaching 
hardware to mounting brackets and supports.  
						

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B. Connect blower motor electrical connector and secure as needed. 
C. Connect drain line at bottom of evaporator and secure with cable tie. 
D. Replace  all  O-Rings  before  connecting  refrigerant  plumbing  to  evaporator 
tube  and fittings.  Torque  refrigerant  line  connections per  tightening 
instructions pg.29. 
E. Connect  outlet  flex  ducts  to the  outlet adapter  on the evaporator  and  secure 
with cable ties. 
F. Service air conditioning system with refrigerant. 
5. Removal  and  Replacement  of Forward  Evaporator Blower  Motor  Assembly 
(LH or RH, Figure 8 and Figure 9) 
 
Removal 
 
A. Disconnect  blower motor electrical connector and  cut  cable  ties  to free  motor 
wiring from cable tie mounts on evaporator. 
B. Remove attaching hardware securing blower motor assembly to evaporator 
enclosure. Remove blower motor and wheel assembly. 
C. Cut wire leads at splices and retain wire and connector lead for reuse on new 
motor. Record correct polarity of connections. 
D. Loosen retaining set screw and remove blower wheel from blower motor 
shaft. Retain blower wheel. 
NOTE 
It  may  be  necessary  to  apply  heat  to  the  set  screw  of  the  blower 
wheel in order to separate the two parts. 
 
Installation/Replacement 
 
A. Install  retained  blower  wheel  on  new  motor. Press  the  blower  wheel  onto  the 
motor shaft until it stops against motor. Back blower wheel away to achieve a 
.030” – .040”  clearance  between  blower  wheel  and  new  motor.  Apply  one 
drop  of  low  strength  Loctite  to  set  screw  and  tighten  against  flat  portion  of 
motor shaft to lock wheel in place (Figure 17). 
 
 
Figure 17:  Fwd Evap Blower Motor and Wheel Assembly 
 
  
						

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B. Install  blower motor and  wheel assembly in  evaporator enclosure  and  secure 
with attaching hardware. 
C. Install  M81824/1-3  or  equivalent  splices  to  motor  wires  and  retained 
connector leads. Observe correct polarity of connections. 
D. Connect  blower motor electrical connector and  secure  to  cable  tie mounts  as 
required. 
 
6. Removal and Replacement of Aft Evaporator Assembly 
(Figure 10) 
 
Removal 
 
A. Discharge the refrigerant. See chapter 6 Servicing for instructions. 
B. Remove belly  panel  below  RH  seat to  gain  access  to the  aft  evaporator 
assembly. 
C. Disconnect electrical connector to evaporator freeze switch. 
D. Disconnect return air transition duct from adapter ring on the aft evaporator. 
E. Disconnect  refrigerant  plumbing  from  evaporator  fittings  once  refrigerant  is 
evacuated. 
F. Remove  attaching  hardware  securing  evaporator  assembly  to  mounting 
brackets and supports. 
G. Remove aft evaporator assembly. 
 
Installation/Replacement 
 
A. Install aft evaporator  assembly  and  secure  with  retained  attaching  hardware 
to mounting brackets and supports. 
B. Connect electrical connector to evaporator freeze switch. 
C. Connect return air transition duct to adapter ring on the aft evaporator. 
G. Replace  all  O-Rings  before  connecting  refrigerant  plumbing  to  evaporator 
tube  and  fittings.  Torque  refrigerant  line  connections per  tightening 
instructions pg.29. 
D. Service air conditioning system with refrigerant. 
 
7. Removal and Replacement of Aft Evaporator Blower Motor Assembly 
(Figure 10) 
 
Removal 
 
A. Remove belly panel to gain access to the aft evaporator blower assembly. 
B. Disconnect blower motor electrical connector. 
C. Remove attaching hardware securing blower motor assembly and mounting 
brackets. Remove blower motor and wheel assembly from blower housing. 
D. De-pin wire leads and retain connector for reuse on new motor. Record 
correct polarity of connections.  
						

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E. Note the clearance between blower wheel and forward mount assembly on 
motor. Record clearance for reference (Figure 18). 
F. Loosen retaining set screw and remove blower wheel from blower motor 
shaft. Retain blower wheel. 
 
NOTE 
It  may  be necessary  to  apply  heat  to  the  set  screw  of  the  blower 
wheel in order to separate the two parts. 
 
G. Remove forward and aft mount assemblies and cooling tube from motor. 
 
Installation/Replacement 
 
A. Install forward and aft mount assemblies and cooling tube on new motor. 
B. Install  retained  blower  wheel  on  new  motor. Press  the  blower  wheel  onto  the 
motor  shaft  until  it  stops  against  motor.  Back  blower  wheel  away  to  achieve 
the  noted clearance  between  blower  wheel  and forward  mount  assembly  on 
motor. Apply one drop of low strength Loctite to set screw and tighten against 
flat portion of motor shaft to lock wheel in place (Figure 18). 
 
 
 
 
 
Figure 18:  Aft Evap Blower Motor and Wheel Assembly 
 
 
C. Install blower motor and wheel assembly in blower enclosure and secure with 
attaching hardware. 
D. Install retained  connector to  motor  wires.  Observe  correct  polarity  of 
connections. 
E. Connect  blower  motor  electrical  connector to  aircraft  wiring and  secure  as 
required. 
  
Back blower wheel away 
to achieve .030-.040 
clearance between blower 
wheel and forward mount 
assembly on motor 
Forward mount 
assembly  
						

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F.  
8. Removal and Replacement of Condenser Assembly (Figure 11) 
 
Removal 
 
A. Discharge the refrigerant. See Chapter 6 Servicing for instructions. 
B. Remove  LH  aft  engine  fairing  from  aircraft  to  gain  access  to  the  condenser 
assembly. 
C. Disconnect both condenser blower assembly electrical connectors. 
D. Disconnect  refrigerant  plumbing  from  condenser and  receiver  drier fittings 
once refrigerant is evacuated. 
E. Remove attaching hardware securing condenser assembly to engine deck. 
F. Remove the condenser assembly. 
 
Installation/Replacement 
 
A. Install  condenser  assembly  and  secure  with  retained  attaching  hardware  to 
engine deck. 
B. Connect electrical connectors to condenser blower assemblies. 
C. Replace all O-Rings before connecting refrigerant plumbing to condenser and 
receiver  drier tube  and  fittings.  Torque  refrigerant  line  connections per fitting 
tightening instructions pg.29. 
D. Service air conditioning system with refrigerant. 
9. Removal and Replacement of Condenser Blower Assembly (Figure 11) 
 
Removal 
 
A. Remove  LH  aft  engine  fairing  from  aircraft  to  gain  access  to  the  condenser 
assembly. 
B. Disconnect the appropriate condenser blower assembly electrical connector. 
C. Remove safety  wire and attaching hardware securing blower assembly to the 
condenser assembly. 
D. Remove the blower assembly. 
 
Installation/Replacement 
 
A. Install  blower  assembly  and  secure  with  retained  attaching  hardware to 
condenser  assembly  and  apply  safety  wire per MIL-P-8564,  using 
MS20995C-32 safety wire. 
B. Connect electrical connector to the condenser blower.