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

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
Revision 8 Page 5 
B. TORQ LOK® FITTINGS: These fittings have two flat mating surfaces that along with 
an  O-Ring  create  a  seal.  Caution  when  assembling  these  fittings; care  should  be 
taken  not  to  damage  the O-Ring (i.e.  nicking,  splitting,  or  crushing  etc.). Green O-
Rings  must  not  be  used  on  these  fittings. (See CHAPTER 7 for torqueing 
procedures). 
The system is also equipped with a Binary switch. This switch is designed to protect 
the  system  against  over-pressure  situations,  or  under-pressure  in  the  event  of 
refrigerant loss from the system. The switch also prevents the system from operating 
in low ambient temperatures below 50º F (10º C). 
The switch operating pressures are: 
Low Pressure Function: 
Cut-out at 28 ± 2.8psi (2.0 ± .2 Kg/cm²) 
Cut-in at 29 ± 4.3 psi (2.1 ± .3 Kg/cm²) 
High Pressure Function: 
Cut-out at 384 ± 30psig (28.0 ± 2.0 Kg/cm²) 
Cut-in at 298 ± 43psig (20.9 ± 2.0 Kg/cm²) 
14. Description of Vapor Cycle Air Conditioner and Installation 
This  section  contains a  general  overview  of  a  vapor-cycle  air  conditioning  system  and 
how  it  functions.  This  type  of  system  operates  in  a  closed  loop,  in  which  the  refrigerant 
absorbs  heat  from  the  cabin  and  ejects  it  into  the  outside  air.  The  refrigerant  then 
returns to the cabin to repeat the cycle. The operation of the system is described below 
(See Figure 2). 
Liquid refrigerant is contained in the receiver-drier under pressure from the compressor. 
The  receiver-drier  also  filters  the  refrigerant  through  a  material  know  as  desiccant.  The 
desiccant  insures  that  the  liquid  refrigerant  leaving  this  component  is  free  of  any  water 
or other contaminants. 
The low pressure (suction) line from the compressor is attached to the evaporator lines, 
and  causes  the  refrigerant  to  be  pulled  out  of  the  receiver-drier  and  through  the 
expansion valves. The expansion valves serve as a controlled spray orifice, to spray the 
correct  amount  of  refrigerant  into  the  evaporator.  This  regulation  of  refrigerant  allows 
the  liquid  to  absorb  the  heat  from  the  cabin  air,  and  transform  it  to  a  vapor  state  just 
prior to its exiting the evaporator assembly. 
The  low  pressure  vapor  is  then  drawn  into  the  compressor  where  its  pressure  is  raised 
to approximately 200 psig (14.06 kg/cm) and its temperature to around 200º F (93.3º C). 
This  high  pressure/high  temperature  vapor  then  travels  to  the  condenser  (a  heat 
exchanger cooled by a flow of outside air). Heat is extracted from the refrigerant, and as 
it cools it condenses back into a liquid and flows into the receiver-dryer, ready to repeat 
the cycle. 
   
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
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15. Refrigeration Cycle Illustration 
 
 
 
Figure 2:  Refrigeration Cycle Illustration 
(NOTE: This illustration is provided as a reference only and may not match actual 
installation) 
 
 
High pressure liquid 
Low pressure vapor 
Low pressure liquid 
High pressure vapor 
Compressor 
Condenser 
Aft Evaporator 
Receiver- 
Drier 
Bypass 
Valve 
Expansion 
Valves 
Fwd Evaporator  
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
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CHAPTER 2 
AIRWORTHINESS LIMITATION SECTION 
 
1. Airworthiness Limitations 
 
The  Airworthiness limitations  section  is  FAA  approved  and  specifies  inspections 
and  other maintenance  required  under  Sections  43.16  and  91.403  of  Federal 
Aviation Regulations unless an alternative program has been FAA approved. 
 
“No airworthiness limitations associated with this type design change.” 
  
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
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CHAPTER 3 
INSPECTIONS AND OVERHAUL  
 
1. Inspection Requirements 
 
PERIODIC INSPECTIONS 
(Hours are aircraft time) 
 
 
Item Annual Every 100 Hours of Operation Special Inspection Information 
Fwd Evaporator Blower(s) X X Check for operation in High and Low settings. 
Aft Evaporator Blower X X Check for operation in High and Low settings. Condenser Blower Motor(s) & Fan blade assembly X X Check for operation.  
Compressor Drive Belt X X Check belt tension and for signs of excessive wear (example: glazing, cracks, and exposed fibers). 
Placards & Markings X X Check for security and legibility. 
Compressor Assembly X X Check for operation, security of attaching hardware, and signs of oil or refrigerant leaks. 
Compressor Mount X X Check mount for cracks and security of the attaching hardware.  
Plumbing and Fittings X X Check for security and signs of oil or refrigerant leaks. Compressor drive pulley  X X Check for security of attaching hardware. 
Blower Electrical Connectors X  Visually inspect the condenser and evaporator blower motors for signs of overheating 
 
2. Inspection Of Blower Electrical Connectors (annual requirement) 
 
a) Locate the Molex electrical connectors that power the aft evaporator and condenser 
blowers. The connectors are at the interface between the blower harness and the aircraft 
harness and identified by their white plastic housing. Note that the evaporator blower 
has an additional connector to inspect located several inches away from the harness 
connector.  
b) De-mate each connector and inspect both mates for signs of overheating 
(discoloration or plastic deformation). If any signs of overheating of the housing are 
present the system must be rendered inoperative and the connector housing and 
contacts replaced before further operation. Contact ACC service dept. for replacement 
parts if necessary. 
   
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
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c) Installation & replacement of the wire harness electrical connectors for the evaporator 
and condenser blowers. 
To avoid potentially serious overheating issues the Molex style connectors (identified 
by their white plastic housing) installed on the aircraft harness for connecting to the 
evaporator and condenser blowers must be installed per ACC procedure PPP23 and 
only using the appropriate terminal crimp tool. This document is available on the 
ACC website www.aircommcorp.com/customer-support/service-manuals/. 
 
3. Component Overhaul / Replacement Schedule 
 
Description Part Number Overhaul / Replacement Hours 
Condenser & Forward / Aft Evaporator Blower Motor & Fan replacement 
 ES73186-9 (Condenser Blower Assembly) ES61064-1(Fwd Evaporator Motor) ES61142-3 (Aft Evaporator Motor) 
The blower manufacturer recommended TBO is 1000 hrs. At the discretion of the operator it is acceptable to operate the blower until failure. A blower failure will result in a reduction in cooling, but no safety-of-flight issues are involved. 
 
  
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
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CHAPTER 4 
LOCATION AND ACCESS 
1. Location of Air Conditioner Components 
 
Nomenclature Description of Location 
Control Panel Located in the existing center console panel between the 
pilot & co-pilot seats 
Forward (Flight Deck) Evaporators Mounted to the center pedestal forward of the instrument 
panel in the chin bubble area 
Aft (Main Cabin) Evaporator Located on aircraft right, below the cabin floor  
Condenser Assembly Located on the left hand side of the aircraft, just aft of 
the engine compartment 
Compressor Assembly Mounted to the main gearbox accessory drive case 
Receiver Drier/Pressure Switch Mounted aft of the condenser assembly 
Bypass Valve Mounted adjacent to the aft evaporator 
Refrigerant Plumbing 
Routed from the compressor, to the area below the 
passenger compartment, and forward to the nose area 
(As the refrigerant plumbing connects the compressor, 
condenser and evaporators, it may be necessary to 
remove several panels to gain access to its 
components). 
Servicing Ports Located in the left hand engine compartment adjacent to 
the condenser assembly 
 
Figure 3:  Layout of Air Conditioner Dual/Single Evaporators 
(Side View) 
   
						

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Figure 4:  Layout of Air Conditioner Dual/Single Evaporators 
(Top View) 
   
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
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Figure 5:  Compressor Installation 
(View Looking Inboard, LH Side)  
  
Transmission (ref)  
ES35135-1 Belt 
EC135-3040-1 
Compressor Assembly 
 
EC135-3004-1 Lower 
Compressor Mount Assembly 
 
EC135-3004-2 Upper 
Compressor Mount Assembly 
 
See Detail “A” 
(next page) 
 
EC135-3008-1 
Bearing Cover 
 
EC135-3020-1 
Compressor 
Adjustment 
Assembly 
See Detail “B” 
(next page) 
EC135-3012-1 
Brace Assembly 
2X   
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
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Figure 6:  Detail “A” Compressor Lower Mount Drive Pulley Assembly 
 
 
 
 
 
 
Figure 7:  Detail “B” Compressor Adjustment Assembly  
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
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Figure 8:  Fwd Evaporator Installation, RH (View Looking Inboard) 
 
 
 
Figure 9:  Fwd Evaporator Installation, LH (View Looking Inboard) 
EC135-6006-1 
Fwd Evaporator Assy, LH 
EC135-6006-2 
Fwd Evaporator Assy, RH 
ES61064-1 
Evaporator Blower Motor 
ES61064-1 
Evaporator Blower Motor 
ES72183-1 
Air Outlet