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

							AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
Revision 6 Page 33 
 
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 
 
Identification  and  elimination  of  system  fitting  leaks  is  extremely important  to  insure  a 
trouble-free operation of this system. 
 
A system which contains a partial charge of refrigerant can be leak tested with the aid of 
an electronic leak detector, and be recharged without evacuating the system. 
 
A  new  or  empty  system  can be  pressurized  with  nitrogen  70-80  psi  (5.1-5.6  kg/cm)  or 
R134a 50 psi (3.5 kg/cm) to conduct a leak survey.  
 
CAUTION 
Do  not  use  compressed  air.  Compressed  air  will  introduce  moisture  into 
the system, which will degrade the operation of the system. 
 
The preferred  method  to  conduct  a  leak  survey  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.  Refrigerant 
will  collect  in  low  areas  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. 
 
If the nitrogen method is used, it will be necessary to mix together a water and mild soap 
solution.  Each  fitting  or  suspected  leak  area  should  be  brushed  with  this  soap  solution 
and watched for evidence of bubbles formed by the escaping nitrogen. 
 
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 system of refrigerant, and install 
new O-rings. 
 
NOTE 
Ensure  that  the  O-ring  is  lubricated with  refrigerant  oil  prior  to  its 
installation. 
  
						

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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 
 
Refrigerant:  
This system is to be charged with Dupont, or equivalent HFC R134a refrigerant only. 
 
Lubricant: 
This system may be serviced with either Polyolester (POE) or Double End Capped 
Polyalkylene Glycol (DEC PAG). DEC PAG is preferred. 
 
CAUTION 
Do not use Polyalkylene glycol (PAG) or Mineral Oil in this system. 
 
 
O-rings:  
As this system is charged  with R134a refrigerant, it must be fitted with Highly Saturated 
Nitriles  (HSN)  O-rings.  This  system  incorporates  two  different  O-ring  fittings,  Torq-Lok 
and  Insert.  The  HSN  O-rings  for  the  Torq-Lok  fittings  are  BLACK  in  color  and  the  HSN 
O-ring for the Insert fittings are GREEN in color. 
   
						

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Revision 6 Page 35 
7. Suggested Spares List 
 
Item Part Number 
Blower Motor – Fwd. Evaporator  S-6164EC-3 
 
Blower Motor – Aft Evaporator  ES61142-1, -2 
 
Blower Assembly – Condenser (Baggage) EC130-7536-2 
 
Blower Assembly – Condenser (Tail Boom) S-7095EC-1 (Alt S-7095EC-2) 
 
Compressor Assembly (Flat Belt) S-3048EC-1 
 
Compressor Drive Belt (Flat) ES35350-3 
 
Compressor Assembly (Ploy V Belt) S-3036EC-1 
 
Compressor Drive Belt (Poly V) ES35130-3 
 
Receiver / Drier Bottle ES43030-5 (200 / 202 systems) 
 ES43042-1 (204 system) 
 
Binary Switch ES57178-1 
 
By-pass Valve ES26194-24 
 
 
HSN O-rings; Insert type (Green) 
Size  
#6 O-ring ES44010-2 
#8 O-ring ES44010-3 
#10 O-ring ES44010-4 
 
HSN O-rings; Torq-Lok Type (Black) 
Size 
#6 O-ring ES44012-2 
#8 O-ring ES44012-3 
#10 O-ring ES44012-4 
 
   
						

							AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
Revision 6 Page 36 
CHAPTER 7 
STANDARD PRACTICES AND INFORMATION 
1. General Information 
 
a. Refer  to Airbus Model  AS350  Maintenance  Manual  for  general  removal  and 
installation procedures associated with basic aircraft equipment and components. 
b. It may be  necessary  to  evacuate  (discharge)  refrigerant  from  the  system  to 
remove  or  replace certain  components.  Instructions  for  servicing  are  found  in 
Chapter 6. 
c. 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. 
d. Retain all parts and attaching hardware for reassembly, unless otherwise noted. 
 
2. Fitting Torque Procedures 
 
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.  
 
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). 
  
						

							AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
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TORQ-LOK ® fittings (regardless of size): Hand tighten, then turn an additional 30 deg. 
 
 
INSERT O-RING FITTINGS    TORQ-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) 
Once  the  fittings  have  been  checked  and  are  found  to  be  free  of  leaks,  torque  seal as 
appropriate. 
 
3. Removal and Replacement of Forward Evaporator Assembly  
(see Figure 4-5) 
 
Removal 
 
a. Remove  LH  and  RH  outlet  flex  ducts from  the  Y-adapter  on  evaporator  by 
removing cable ties. 
b. Remove  attaching  hardware  securing  evaporator  assembly  to  aft support 
bracket.  Lift  and  slide  evaporator  aft  enough  to  access  drain  line  and  refrigerant 
lines. 
c. Disconnect drain line from bottom of evaporator by removing cable tie. 
d. Evacuate the refrigerant from the system. Refer to Chapter 6 Servicing p.30. 
e. Disconnect refrigerant  plumbing  from evaporator  fittings. Always  use  a  back-up 
wrench. 
f. Disconnect blower motor electrical connector. 
g. Remove forward evaporator assembly. 
 
Replacement 
 
a. Position evaporator and connect blower motor electrical connector and secure as 
needed. 
b. Connect drain line at bottom of evaporator and secure with cable tie. 
c. Replace  all  O-rings before  connecting  refrigerant  plumbing  to  evaporator  fittings 
using a back-up wrench. Torque refrigerant line connections per section 2 p.36. 
d. Slide  evaporator until  forward  support tab  fully  engages  into  forward  mount. 
Secure evaporator with attaching hardware to aft support bracket. 
e. Connect LH and RH outlet flex ducts to Y-adapter on evaporator and secure with 
cable ties. 
f. Service air conditioning system with refrigerant per Chapter 6, p.30. 
   
						

							AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
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4. Removal  and  Replacement of  Forward Evaporator Blower Motor 
Assembly (Figure 7-1 below) 
 
Removal 
 
a. Remove forward evaporator as per paragraph 2. 
b. Disconnect blower motor electrical connector. 
c. Remove attaching hardware securing blower motor assembly to evaporator 
enclosure. Remove blower motor assembly. 
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. 
 
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. 
b. Install blower motor in evaporator enclosure and secure with attaching hardware. 
c. Connect blower motor electrical connector and secure as needed. 
d. Install forward evaporator as per paragraph 2. 
 
 
 
 
 
 
 
 
Figure 7-1 – Forward Evaporator 
  
S-6164EC-3 
Blower Motor Assembly 
ES73100-5 
Blower Wheel  
						

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Revision 6 Page 39 
5. Removal and Replacement of Aft Evaporator Assembly 
(Figure 4-9 & 4-10) 
 
Removal 
 
a. Disconnect  refrigerant  plumbing  from evaporator  fittings  once  refrigerant  is 
evacuated. Always use a back-up wrench. 
b. Remove attaching  hardware  and  disconnect  duct  from  inlet  of  evaporator. 
Remove flex duct from outlet of evaporator by removing cable ties. 
c. Remove attaching hardware securing evaporator assembly to transmission deck. 
d. Disconnect drain line from bottom of evaporator by removing cable tie. 
e. Disconnect wiring harness connector to evaporator assembly. 
f. Remove aft evaporator assembly. 
 
Replacement 
 
a. Position  evaporator  and  connect  drain  line  at  bottom  of  evaporator.  Secure  with 
cable tie. 
b. Mount evaporator and secure with mounting hardware to transmission deck. 
c. Connect  duct  and  flex  duct  to  inlet  and  outlet  of  evaporator  and  secure  with 
attaching hardware and cable ties. Seal duct joint to evaporator with black RTV. 
d. Connect wiring harness connector to evaporator. 
e. Replace  all  O-rings before  connecting  refrigerant plumbing  to  evaporator  fittings 
using a back-up wrench. Torque refrigerant line connections per section 2, p.36. 
f. Service air conditioning system with refrigerant per Chapter 6, p.30. 
 
6. Removal and Replacement of Aft Evaporator Blower Motor  
(Figure 7-2 below) 
 
Removal 
 
a. Disconnect blower motor electrical connector. 
b. Remove attaching hardware securing blower assembly and cup housing to aft 
evaporator enclosure. 
c. Remove attaching hardware securing blower and blower wheel to cup housing. 
Remove blower assembly. 
d. Loosen retaining set screw and remove blower wheel from blower motor shaft. 
Retain blower wheel. 
e. Remove heat shrink and splices to motor wires. Retain Molex receptacle and 
wiring. 
 
NOTE 
It may be necessary to apply heat to the set screw of the blower wheel in 
order to separate the two parts. 
  
						

							AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
Revision 6 Page 40 
 
Figure 7-2 – Aft Evaporator Blower Motor, Pre-2015 kits with Molex connectors 
 
Replacement 
 
a. Install splices to retain Molex receptacle wiring and replacement motor wires. 
Cover with heat shrink. Ensure wiring polarity is observed as per Figure 7-2. 
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 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. 
c. Attach motor and blower wheel to cup housing using attaching hardware. 
d. Install blower assembly and cup housing to aft evaporator enclosure using 
attaching hardware. 
e. Connect blower motor electrical connector and secure as needed. 
 
7. Removal and Replacement of Condenser Assembly 
(Side Baggage Compartment) (Figure 4-11 & 4-12) 
 
Removal 
 
a. Remove attaching hardware securing forward inner baggage compartment panel 
to condenser assembly. Remove baggage compartment panel. 
b. Disconnect  refrigerant  plumbing  from condenser fittings  once  refrigerant  is 
evacuated. Always use a back-up wrench. 
c. Remove  attaching  hardware  securing blower  support  mount  to condenser vane 
axial blower assembly. 
M81824/1-2 Splice 2X 
Cover wire and splices with heat shrink 
ccw 
ES61142-1, -2 Motor  
						

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d. Remove lower attaching hardware securing baffle plate assembly support tube to 
aircraft structure. 
e. While  supporting  condenser  assembly,  remove  attaching  hardware  securing 
condenser  hangar  brackets on  each  side  of  condenser to  existing  horizontal 
support. 
f. Remove condenser assembly. 
 
Replacement 
 
a. Position condenser and  secure  with  attaching  hardware  to hangar  brackets  on 
each side of condenser to existing horizontal support. 
b. Install lower  attaching  hardware  securing  baffle  plate  assembly  support  tube  to 
aircraft structure. Torque support tube bolt to 20-25 in-lbs (2.25-2.82 Nm) 
c. Secure  blower  support  mount  to  condenser  vane  axial  blower  assembly  with 
attaching hardware. 
d. Replace  all  O-rings  before  connecting  refrigerant  plumbing  to condenser fittings 
using a back-up wrench. Torque refrigerant line connections per section 2 p.36. 
e. Install forward inner baggage compartment panel to condenser assembly. 
f. Service air conditioning system with refrigerant per Chapter 6, p.30. 
 
8. Removal and Replacement of Condenser Blower Assembly 
(Side Baggage Compartment) (Figure 4-11 & 4-12) 
 
Removal 
 
a. Disconnect blower assembly wiring from RF filter. Observe position and polarity 
of the wires for reinstallation. 
b. Remove attaching hardware that secures condenser blower assembly housing to 
condenser assembly. 
c. The discrepant blower assembly can be returned for core exchange credit. 
Contact ACC Customer Service for instructions. 
 
Replacement 
 
a. Install blower assembly to condenser assembly with attaching hardware. 
b. Connect blower wiring to RF filter and secure as needed. Observe polarity of the 
wires (Black – negative; Red – positive). 
 
9. Removal and Replacement of Condenser Assembly 
(Tail Boom) (Figure 4-13) 
 
Removal 
 
a. Remove attaching hardware from condenser cover panel. Remove panel. 
b. Remove both condenser blower assemblies per section 10 below. 
c. Remove both blower lower support brackets attached to the exhaust duct tray. 
d. Disconnect  refrigerant  plumbing  from  condenser  fittings  once  refrigerant  is 
evacuated. Always use a back-up wrench. 
e. Remove 7 nuts securing condenser assembly.  
						

							AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
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f. Remove both foam lined air block panels. 
g. Remove condenser assembly. 
 
 
Replacement 
 
a. Position condenser and air block panels and secure with attaching hardware. 
b. Replace  all  O-rings  before  connecting  refrigerant  plumbing  to  condenser  fittings 
using a back-up wrench. Torque refrigerant line connections per section 2 p.36. 
c. Install both condenser blower assemblies with support brackets. 
d. Install condenser assembly cover panel to condenser assembly. 
e. Service air conditioning system with refrigerant per Chapter 6, p.30. 
10. Removal and Replacement of Condenser Vane Axial Blower 
(Tail Boom) (Figure 4-13) 
 
Removal 
 
a. Remove attaching hardware condenser assembly cover panel to condenser 
assembly. Remove cover. 
b. Disconnect condenser blower connector from harness connector. 
c. Remove 4 each screws attaching condenser blower assembly to the exhaust 
housing. 
d. Remove blower lower support bracket attached to the exhaust duct tray. 
e. Remove blower assembly. 
 
Replacement 
 
a. Position condenser blower and install attaching hardware and lower support 
bracket. 
b. Re-connect blower electrical plug to harness socket. 
c. Install condenser assembly cover panel to condenser assembly. 
 
11. Removal and Replacement of Compressor Drive Belt 
(Figure 4-3 & 4-4) 
NOTE 
Generally,  AS350 Single  Hydraulic  configured  helicopters  (and  Dual 
Hydraulic built before 2003) use the Flat belt compressors. Dual Hydraulic 
configured  helicopters  (Aircraft  built after  2003)  use  the  Poly  V  belt 
compressor. 
 
 
Removal 
 
a. Cut safety wire on compressor belt tensioning link and belt tensioning link jam 
nuts, and loosen respective jam nut(s). 
b. Loosen upper and lower compressor pivot bolts and lower link assembly 
mounting bolt on the compressor mount to allow freedom of movement of 
compressor. 
c. Adjust belt tensioning link to loosen drive belt.