AirComm Corporation Bell 412 Air Conditioner Instructions for Continued Airworthiness User Manual

AIR CONDITIONER SERVICE MANUAL 412AC-208M 
 
Revision 14 Page 11 
F. Inspection of Air Conditioner Compressor Mount Assy. 
a. Visually inspect compressor mount of any signs of the following: 
1. Any cracks. 
2. Security of attaching hardware.  
3. Elongation of component mounting holes. 
4. Any loose rivets. 
 
G. Inspection of Air Conditioner Refrigerant Plumbing 
b. Visually inspect plumbing and fittings for any signs of the following: 
1. Refrigerant gas or oil leaks. 
2. Chaffing or excessive...

AIR CONDITIONER SERVICE MANUAL 412AC-208M 
 
Revision 14 Page 12 
 
CHAPTER 4 
LOCATION AND ACCESS 
 
1. LOCATION OF AIR CONDITIONER FEATURES 
 
Nomenclature Description of Location 
Air Conditioner Circuit Breaker Panel Located on the forward L/H side adjacent to 
the overhead circuit breaker panel. 
Air Conditioner Control Panel Located in the center pedestal. Exact location 
may vary depending on how the aircraft is 
equipped or configured. 
Relay Panel Assembly Located adjacent to the main...

AIR CONDITIONER SERVICE MANUAL 412AC-208M 
 
Revision 14 Page 13 
CHAPTER 5 
PLACARDS AND MARKINGS 
 
1. PLACARD AND MARKING INFORMATION 
 
System Charging Instruction Placard 
(Mounted to the R/H side of the condenser housing) 
 
NOTE 
Newer systems do not include the “BOULDER, COLORADO” annotation on the System 
Charging Instructions Placard. 
 
NOTE 
Systems shipped after June 1, 2015, include both “Polyester oil” and “Ultra PAG oil” in the 
annotation on the System Charging Instructions Placard....

AIR CONDITIONER SERVICE MANUAL 412AC-208M 
 
Revision 14 Page 14 
CHAPTER 6 
SERVICING 
 
1. SAFETY PRECAUTIONS 
 
CAUTION 
Refrigeration servicing should be performed by qualified personnel only. 
 
The refrigerant used in the air conditioning system is the environmentally safe HFC 
R134a. This refrigerant 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 to protect...

AIR CONDITIONER SERVICE MANUAL 412AC-208M 
 
Revision 14 Page 15 
CAUTION 
It is mandatory that the system be leak free to ensure trouble free operation.  Continuous 
operation of the system with insufficient charge will result in compressor damage. 
 
E. After the system is proven to be leak free, the system should be evacuated for a 
minimum of ½ hour before being charged with HFC R134a. 
 
F. Charging the system with 6.25 lbs. (2.8 Kg.) of R134a refrigerant is the most accurate 
method of charging....

AIR CONDITIONER SERVICE MANUAL 412AC-208M 
 
Revision 14 Page 16 
recommended  method.  Always  rotate  clockwise  to  insure  against  loosening  the 
compressor shaft nut. 
If  the  system  was  charged  per  Section 2 paragraph G of  this  Chapter  then  disregard 
manual rotation. 
Operate  system  normally,  check  for  evaporator  fan  operation  on  both  high  and  low 
speed settings. Insure that condenser fans are operating and airflow direction is correct.  
 Ambient temperature between 60 OF...

AIR CONDITIONER SERVICE MANUAL 412AC-208M 
 
Revision 14 Page 17 
At  these  ambient  temperatures  this  test  should  not  be  conducted  for more  than  15 
minutes.  Testing  the  evaporator  fan  operation  using  the  vent  position  prior  to  rolling  out 
of the hangar and prior to running the air conditioner system is recommended. Check for 
evaporator fan operation on both high and low speed settings. Insure that condenser fan 
is operating and the airflow direction is correct. 
 Ambient...

AIR CONDITIONER SERVICE MANUAL 412AC-208M 
 
Revision 14 Page 18 
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. 
 
A. New Installations - The total system oil charge is 16.0 oz. (473 ml.) of R134a Ultra PAG 
Refrigerant Oil. The compressor is charged with 9.0 oz. (266 ml.) of oil at the factory, an 
additional 7.0 oz. (207 ml.) of oil must be added at the time of...

AIR CONDITIONER SERVICE MANUAL 412AC-208M 
 
Revision 14 Page 19 
 
 
Figure 5:  Compressor Counter Weight and Dipstick 
 
B. Component  Replacement - Once  a  system  is  in  operation  the  lubrication  is  circulated 
through  the  system  along  with  the  refrigerant.  The  refrigerant  becomes  saturated  with 
the oil and carries it throughout the system, lubricating the compressor internal parts. No 
other  component  in  the  air  conditioning  system  requires  lubrication.  Excessive  oil  in...

AIR CONDITIONER SERVICE MANUAL 412AC-208M 
 
Revision 14 Page 20 
F. 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...