AirComm Corporation Bell 407 Air Conditioner Instructions for Continued Airworthiness User Manual

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
Revision 11  Page 34 
 
CAUTION 
When  reclaiming  refrigerant,  be  sure  to  note  any  oil  that  is  removed  from  the  system,  and 
replace  the  lost  oil  before  or  during  re-servicing.  Maintaining  a  proper  oil  and  refrigerant 
charge  is  critical  to  the  life  of  the  compressor  assembly. Excessive  system  oil  charge  will 
reduce cooling performance. 
 
5.  AMBIENT TEMPERATURE EFFECTS ON SERVICING 
 
Running  the  system  when  the  ambient  temperature  is  below  60 OF  will  present 
unusual  (low)  suction  and  discharge  pressures  on  system  gauges.  An  overcharge 
condition  is likely  if  the  process  described  in  the previous  paragraphs  A  through G  
is  followed  when  the  ambient  temperature  is  below  60 OF.  Running  the  air 
conditioning  system  when  the  outside  air  temperature  is  appreciably  colder  than 
the  normal  design operating  temperatures  may  result  in  damage  to  the 
compressor. The following guidelines will provide means to mitigate the chances of 
system damage. 
The  following  assumes  that  the  system  is  either  a  freshly  installed  system  or  a 
previously operated system with a newly installed compressor. 
 Ambient temperature above 60OF: 
If  the  system  was  charged  by  refrigerant  weight  utilizing  a  charging  station  and 
the  compressor  has  not  been  rotated  since  the  oil  and  refrigerant  were  added, 
then  manually  rotate  the  compressor  shaft  clockwise  a  minimum  of  10  full 
revolutions  prior  to  running  the  compressor.  A  socket  or  wrench  applied  to  the 
shaft nut is the recommended method. Always rotate clockwise to insure against 
loosening the compressor shaft nut. 
If  the  system  was charged  per  Section  3  paragraph  F  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 and 80 OF: 
At  these  ambient  temperatures  system  charging  is  to  be  accomplished  by 
refrigerant  weight.  The  method  mentioned  in  Chapter  6,  Section  3,  Paragraph  F 
(above)  is  not  applicable  at  these  condenser  inlet  temperatures.  It  is 
recommended  that  the  aircraft  heater  be  used  during  air  conditioner  system 
testing in order to provide a heat load to the evaporators.  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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Manually  rotate  the  compressor  shaft  clockwise  a  minimum  of  10  full  revolutions 
prior  to  running  of  compressor. A  socket  or  wrench  applied  to  the  shaft  nut  is 
recommended  method.  Always  rotate  clockwise  to  insure  against  loosening  the 
compressor shaft nut. 
Normal suction and discharge pressures are not expected under these conditions 
and  the  evaporators  may  be  cold enough  to  cause  the  freeze  switch  to  activate 
and the bypass valve to open and close in a cyclic pattern. 
Even  though  the  bypass  valve  may  be  cycling  this  test  may  be  conducted  for 
sufficient  time  to  thoroughly  check  for  condenser  blower  and  fan  operation. 
Check  for  evaporator  fan  operation  on  both  high  and  low  speed  settings.  Insure 
that  the  condenser  fan  is  operating  and  the  airflow  direction  is  correct.  Low  side 
pressure may  be observed  to  be  higher than  expected  when  the  bypass  valve  is 
open. 
 Ambient Temperatures between 60 OF and 32 OF: 
At  these  ambient  temperatures  system  charging  is  to  be  accomplished  by 
refrigerant  weight.  The  method  mentioned  in  Chapter  6,  Section  3,  Para.  F 
(above)  is  not  allowed  at  these  condenser  inlet  temperatures.  It  is  required  that 
the aircraft heater, or another means of elevating the evaporator inlet air, be used 
during  air  conditioner  system  testing  in  order  to  provide  a  heat  load  to  the 
evaporators. 
It  is  recommended  that  the  aircraft  be  warmed  in  a  heated  hangar  immediately 
prior  to  running  the  air  conditioner  test.  Upon  removing  the  aircraft  from  the 
heated  environment  the  test  should  be  started  within  ten  minutes  or  as  soon  as 
practical. 
Manually  rotate  the  compressor  shaft  clockwise  a  minimum  of  10  full  revolutions 
prior  to  running  of  compressor.  A  socket  or  wrench  applied  to  the  shaft  nut  is 
recommended  method.  Always  rotate  clockwise  to  insure  against  loosening  the 
compressor shaft nut. 
Normal suction and discharge pressures are not expected under these conditions 
and  the  evaporators  may  be  cold  enough  to  cause  the  freeze  switch  to  activate 
and the bypass valve to open and close in a cyclic pattern. 
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  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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settings.  Insure  that  condenser  fan  is  operating  and  the  airflow direction  is 
correct. 
 Ambient Temperature less than 32 OF: 
There  is  no  safe  way  to  operate  the  air  conditioning  compressor  with  ambient 
temperatures  below  32 OF.  Much  of  the  system  can  be  tested  for  proper 
operation even though the compressor cannot be run. 
Charge the system by refrigerant weight only. 
Manually rotate the compressor shaft clockwise a minimum of 10 full revolutions. 
A  socket  or  wrench  applied  to  the  shaft  nut  is  recommended  method.  Always 
rotate clockwise to insure against loosening the compressor shaft nut. 
Temporarily disconnect the wire energizing the compressor clutch. 
Run  the aircraft and  turn  the  switch  to  air  conditioning.  Check  the condenser fan 
for operation and correct direction of airflow. Check evaporator fans for airflow on 
both high and low settings. 
 
6. PURGING PROCEDURE 
 
 If the system has become contaminated or if the amount of oil in the system is unknown, 
 the following purge steps will prep the system for charging.  
 
 1. Remove all refrigerant from the system and discard. Ensure the charging station is     
     cleaned afterwards from the contaminated oil and refrigerant. 
 
 2. Disconnect all tubing and hoses from the system components. 
 
 3. Purge all hoses and tubes using solvents specifically made for air conditioning      
     systems such as Four Seasons Dura II A/C flush solvent (Isopropyl alcohol or     
     Denatured alcohol are acceptable substitutes). A/C flushing equipment available from      
     sources such as hecatinc.com is also recommended. 
 
 4. (This step does not need to be completed if the compressor is being replaced) 
     Remove the compressor from the aircraft, remove the drain plug and let the        
     compressor drain. Rotate the compressor and allow it to drain again. Repeat this      
     process until the compressor no longer has fluid inside. Do not use solvent to clean   
     the compressor. This will damage and possibly destroy the compressor. Add 8.0   
     ounces of Ultra PAG oil to the compressor (see section 3.0 below) and ensure the O-  
     ring on the drain plug is undamaged and retighten. 
 
 5. Purge the evaporators using air conditioner solvent (or equivalent i.e. Isopropyl  
     alcohol, Denatured alcohol). Flush the evaporator in the same direction as refrigerant    
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
Revision 11  Page 37 
     flow. The solvent should enter from the expansion valve side and exit on the     
     discharge side until the solvent runs out clean. 
 
 6. Purge the condenser using air conditioner solvent (or equivalent i.e. Isopropyl alcohol, 
     Denatured alcohol). 
 
 7. Flush the bypass valve with air conditioner solvent. Do not use pressure to force   
     solvent through the valve. 
 
 8. Replace the receiver drier bottle. THIS IS CRITICAL AND MUST BE PERFORMED. 
 
 9. Reconnect all components. Replace O-rings as needed. 
 
 10.Reconnect the compressor hose and place the system on a constant vacuum for 1   
      hour minimum. 
 
 11. Service the system with fresh R134a refrigerant and run an operational check out. 
 
 
7. LUBRICATION INFORMATION 
 
 
SYSTEM REFRIGERANT & OIL CHARGE 
 
System Description Refrigerant Charge Oil Charge 
407 Air Conditioner Single 
Forward Evaporator 2.4 lbs. 1.1 kg. 8.0  fl. oz. 237 ml. 
407 Air Conditioner Dual 
Forward Evaporator 2.6 lbs. 1.2 kg. 8.0  fl. oz. 237 ml. 
 
 
CAUTION 
This system may be serviced with either Polyolester (POE) or Double End Capped 
Polyalkylene Glycol (DEC PAG) oil.  Polyalkylene Glycol oil 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 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).  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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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  oil  charge  is  continuously  circulated  by  the  refrigerant  during  the  operation  of  the 
system.  A  quantity  of  oil  is  trapped  by  the  compressor,  as  well  as  by  other  parts  of  the 
system. 
 
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 
 
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 compressor. Add ½ oz. to the total measured to account for 
unrecoverable  oil  in  the  old  compressor.  This  total  is  what  is  needed  in  the  new 
compressor.  Use  a  minimum  of  3  oz.  if  less  was  recovered. New  compressors  come 
from Air  Comm  charged  with  8 oz.  (237 cc) of  oil. This  should  be  adjusted  according  to 
the  amount  of  oil  recovered  from  the  old  compressor  and  any  other  components  being 
replaced.  The  receiver  drier  should  always  be  replaced  when  the  compressor  is 
replaced or when the system has been open for an appreciable time, which accounts for 
another 1.5 oz. of oil that should be added. 
 
Below is an example of a compressor (and receiver drier) replacement for illustration: 
 
Evacuating  the  system  recovers  1.5  oz.  of  oil.    Draining  the  old  compressor 
recovered  2.0  oz.  of  oil.    Adding  0.5  oz.  of  residual  unrecoverable  oil  in  the 
compressor  gives  2.5  oz.  The  new  receiver/drier  requires  an  additional  1.5  oz., 
plus 1.5 oz. lost when the refrigerant was evacuated from the system. So the total 
oil  needed  in  the  replacement  compressor  for  this  case  is  5.5  oz.  Since  the  new 
compressor comes with 8 oz. of oil, remove the oil fill plug and pour out 2.5 oz. of 
oil.  Torque compressor oil fill cap to 132-216 in-lb. 
 
The  total  system  oil  charge  is  7.5 – 8.0 fl. oz.  (237 ml.)  of  Refrigerant  Oil.  The 
compressor is charged with 8.0 fl. oz. of oil at the factory.    
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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NOTE 
Maintaining the correct amount of refrigerant and refrigerant oil in the system 
is critical for ensuring the long life of the compressor. 
 
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.  
 
The Service Ports for this system are located in the upper aft right-hand corner of 
the baggage compartment. 
 
8. SYSTEM LEAK CHECK 
 
Identification  and  elimination  of  system  fitting  leaks  is  extremely  important  to 
ensure 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.  DO  NOT  USE  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. 
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 ensure proper  torque  has  been 
applied  to  the  fitting.  If  the  system  continues  to  leak,  reclaim  the  system 
refrigerant, and install a new O-ring.  
   
						

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NOTE 
Ensure 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. 
9. SUGGESTED EQUIPMENT FOR SERVICING 
 
A. Recovery / Recycling / Recharging Station 
Any model manufactured to comply with specification SAE J2788 
 
B. Electronic Leak Detector (R134a compatible) 
 (Example: Micro-Tech III, Robinair, Snap-on, or equivalent) 
 
C. Manifold and gauge set (R134a compatible) 
 (Example: Robinair, Snap-on, or equivalent) 
 
10. CONSUMABLE MATERIALS 
A. Refrigerant: 
This  system  is  to  be  charged  with DuPont,  or  equivalent  HFC  R134a 
refrigerant only.  
 
B.    Lubricant: Ultra PAG refrigerant oil. See Lubrication information, pg. 35. 
 
C. O-rings: As this system is charged with R134a refrigerant, it must be fitted 
with  Highly  Saturated  Nitrile (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-rings for  the 
Insert fittings are GREEN in color. 
 
D. Loctite thread sealer 554 (or equivalent). 
 
E. Torque-Seal Anti Sabotage Lacquer. 
 
6. SUGGESTED SPARES LIST 
 
Item Part Number Affectivity 
Fwd Evaporator Blower Motor ES61064-10 
Aft Evaporator Blower Motor ES61062-2  Kit S/N 1 thru 131 
(See Note) 
Aft Evaporator Blower Motor ES61142-1 Kit S/N 132 & Subsequent 
Condenser Blower Assembly ES73186-1 
  (ES73190-1 ALT)  
Compressor Assembly S-3008EC-6  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
Revision 11  Page 41 
Compressor Drive Belt  7270 (7265 ALT) 
Receiver / Drier Bottle ES43034-1 
Binary Switch ES57178-1 
By-pass Valve ES26194-2 Kit S/N 1 thru 146 
By-pass Valve ES26194-25 Kit S/N 147 & 
subsequent 
Relay – Evaporator W389CX-8 
Relay – Condenser W389CX-13 
Relay – AC Control W389DCX-3 
Temperature Control Switch ES57170-3 
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) 
#6 O-ring ES44012-2 
#8 O-ring ES44012-3 
#10 O-ring ES44012-4 
Note: ES61062-2 Motor is no longer available.  Order replacement S-6102EC-4 Blower 
Assembly and S-6058EC-10 Elbow.  
   
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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CHAPTER 7 
STANDARD PRACTICES INFORMATION 
 
1. FITTING TORQUING PROCEDURES AND TORQUE 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. 
 
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). 
 
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).  
						

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Once  the  fittings  have  been  checked  and  are  found  to  be  free  of  leaks,  torque  seal 
as appropriate. 
 
2. REMOVAL  &  REPLACEMENT  OF  CONDENSER  BLOWER  MOTOR &  FAN 
ASSEMBLY 
 
REMOVAL 
CAUTION 
It is recommended that the battery and external power be disconnected before 
starting work. 
 
A. Remove  the  (13)  thirteen  AN525-10R12  Screws  that  attach  the  S-
7062EC-1  Blower  assembly  to  the  lower  contour  of  the  belly  panel. This 
will  allow  the  condenser  scoop  assembly  to  pivot  on  the  forward  hinged 
support plate. 
 
CAUTION 
Be sure to support the blower assembly when removing the attaching hardware 
to prevent damage to the condenser housing, blower assembly, or the aircraft. 
 
B. Remove  safety  wire  that  secures  the  (4)  AN3H-3A  bolts  (2)  two  on  each 
side  that  attach  the  ES73186-1  Blower  motor  &  Fan  assembly  to  the 
condenser scoop assembly, and remove bolts. 
 
C. Disconnect  the  ES73186-1  Blower  motor  &  Fan  assembly  at  the  Molex 
connector. 
 
D. Once the mounting bolts have been removed, the blower can be removed 
and replaced as required. 
 
REPLACEMENT  
A. Locate  the  new  blower  assembly  and  install  the  fasteners, torqueing the 
bolts to 50 to 70 inch lbs. (5.7-8.0 Nm) and safety using .032 safety wire. 
 
B. Reconnect the Molex connector. 
 
C. Reinstall  the  (13)  thirteen  AN525-10R12  Screws  that  secure  the  S-
7062EC-1 Blower assembly to the lower contour of the belly panel. 
 
D. Apply power, and operate the Air conditioner by placing the control switch 
in  the  A/C position  several  times  to ensure there  is  no  binding  and  for 
proper operation of the Blower motor & Fan assembly.