AirComm Corporation Cessna 414 421 Air Conditioning System Service Manual R134a

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2.2 Electrical Driven Compressor Systems 
 
Electrically operated systems use the aircraft electrical system and are operable 
in most normal flight modes.  Air conditioning may be operated with ground 
external power or the aircraft electrical system providing voltage to the proper 
bus. 
 
The compressor and condenser are manufactured on an assembly pallet. In 
most cases, the compressor drive and condenser fan drive are both driven by a...

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2.3  Engine Driven Compressor Systems 
 
Engine driven systems use compressors that are engine mounted; or on some 
rotorcraft, driven off the tail rotor drive shaft.  A pulley via a V type belt turns the 
compressor.    A clutch mounted on the compressor engages the compressor 
when the air conditioning system is selected ON. 
 
The condenser uses a separate fan with electrical motor to supply cooling air.  
The condenser cooling air (ambient...

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3.0 REFRIGERANT SERVICING 
 
3.1 General 
 
The air conditioning system uses refrigerant R134a and the compressor 
lubricating oil used is Polyolester Oil viscosity grade (ISO) 68.  No other 
refrigerant or compressor oil should be used. 
 
Refrigerant R134a is non explosive, non-flammable, non -corrosive, has 
practically no odor, and is heavier than air.  Although R134a is classified as a 
safe refrigerant, certain precautions must be observed...

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3.2 Discharging System 
 
A. General 
 
The air conditioning system refrigerant must be discharged prior to disconnecting 
or removing components in the refrigerant loop.  Federal law prohibits 
discharging refrigerant into the atmosphere.  Use only an R134a compatible 
recycling/recovery unit when discharging the air conditioning system. 
 
 
B. Tools and Equipment 
 
 
Designation Ref. No.  
Qty  
Remarks 
 
 
Service Pressure Gauge  Comm....

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3.3 Evacuating System 
 
A. General 
 
The air conditioning system must be evacuated prior to charging the system with 
refrigerant.  Evacuating the system removes any moisture that may be in the 
system.  Use only an R134a compatible recycling/recovery unit when evacuating 
the air conditioning system. 
 
 
B. Tools and Equipment 
 
 
Designation  
Ref. No.  
Qty  
Remarks 
 
 
Service Pressure Gauge  
Comm. Avail.  
1  
None 
 
R134a Compatible...

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3.4 Charging System 
 
A. General 
 
Use only R134a refrigerant when charging air conditioning system.  Federal law 
prohibits discharging refrigerant into the atmosphere.  Use only R134a 
compatible recycling/recovery unit when charging the air conditioning system. 
 
B. Tools and Equipment 
 
 
Designation  
Ref. No.  
Qty  
Remarks 
 
 
Service Pressure Gauge  
Comm. Avail.  
1  
None 
 
R134a Compatible 
Recycling/Recovery 
Unit  
Comm. Avail....

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3.5 Flushing System 
 
A. General 
 
The following procedure is used to whenever the compressor is replaced and 
when system contamination is suspected. 
 
B. Tools and Equipment 
 
Designation Ref. No. Qty Remarks 
ACC Hose Coupler Tool  See Procedures  A/R  None 
Service Pressure Gauge  Comm. Avail.  1  None 
R134a Compatible 
Recycling/Recovery Unit Comm. Avail.  1  None 
Polyolester Oil  Comm. Avail.  A/R  Viscosity ISO 68 
 
System Flushing...

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8.  Disconnect all of the expansion valves from the evaporator assemblies.  Attach 
the hose coupler tool in place of the expansion valves on all evaporator 
assemblies.  Use caution in handling the expansion valves.  Do not support the 
expansion valve by its remote bulb tubing.  Do not disconnect the external 
equalization port fitting if the expansion valve is an externally equalized style 
(ES26105-1 and ES26106-1). 
 
  O-ring Style Coupler...

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20. Inspect the binary pressure switch for damage and debris.  Flush with dry 
nitrogen or clean dry compressed air before re-installing.  Use new o-rings. 
 
21. Install a new receiver/drier bottle.  Do not reuse the old bottle under any 
circumstance.  Use new o-rings. 
 
Caution:   Receiver/drier bottles left open to the atmosphere for more than 10 
minutes must be discarded and replaced with new. 
 
22. Evacuate the system per the refrigerant...

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4.0 GENERAL SERVICING 
 
4.1 General 
 
General service procedures are provided to keep the air conditioning system 
operating at peak efficiency.  Procedures are provided for general maintenance 
tips, inspection intervals, maintenance of the plumbing system, to repair hoses, 
and to clean coils.  Procedures are also provided for removal and installation of 
the expansion valve. 
 
CAUTION:  Do not operate air conditioning system with condenser...