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

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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Figure 15:  Relay Panel & Circuit Breaker Detail View, 407EC-201 and 202 Systems  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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Figure 16:  Relay Panel & Circuit Breaker Detail View, 407EC-203 Systems  
    
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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Figure 17:  Forward Evaporator Installation, 407EC-201 and 202 Installations, Dual 
forward evaporator installation shown.  Single forward evaporator installation may have 
evaporator mounted in RH or LH chin bubble.  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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Figure 18:  Forward Evaporator Installation, 407EC-203 Installation  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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Figure 19:  – Refrigerant Plumbing Dual Forward Evaporator installation shown  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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CHAPTER 5 
PLACARDS AND MARKINGS 
 
1. PLACARD AND MARKING INFORMATION 
 
System Charging Instruction Placard S-2507EC-7/-8 
(Mounted adjacent to the air conditioner service ports on the R/H side of the 
baggage compartment, aft of the baggage compartment door). 
 
 
 
System Charge is 2.4 lb. (1.1 kg) for Single Evap., 2.6 lb. (1.2 kg) for Dual Evap. 
 
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 407EC-200M-2 
 
 
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Tail rotor Drive Pulley torque requirements label S-2501EC-1 
(Mounted on Aft fire wall of engine compartment above compressor) 
 
 
 
 
 
 
Flywheel Weight 407-340-002-101removal placard S-2501EC-2 
(Mounted on the Aft fire wall of engine compartment above compressor.) 
 
 
    
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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CHAPTER 6 
SERVICING 
 
1. SAFETY PRECAUTIONS 
 
CAUTION 
Refrigeration servicing should be performed by qualified personnel only. 
 
J. 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  the  parts 
involved, and the person working on the system. 
 
Liquid  R134a  at  normal  atmospheric  pressure  and  temperature  evaporates  so 
quickly that it tends to freeze anything that it contacts. Care must be taken to prevent 
any refrigerant from coming into contact with the skin, especially the eyes! 
 
WARNING 
Always wear safety goggles when servicing any part of the refrigerant system. 
Should any liquid refrigerant contact the skin or eyes, seek medical attention 
immediately even if the irritation ceases. 
 
WARNING 
Never weld, use a flame-type leak detector, blow torch, solder, steam clean, bake on 
aircraft finish, or use excess amounts of heat on, or in the immediate area of 
refrigerant supply tank. 
 
2. SERVICING INFORMATION 
 
A list of suggested servicing equipment is provided later in this chapter. 
 
3. SERVICING PROCEDURE USING A SERVICE CART 
 
A. Connect  the  service  manifold  and  vacuum  pump  to  the  service  ports  located  in 
the upper aft right hand corner of the baggage compartment. 
 
B. Turn on the vacuum pump and open both valves to evacuate the system. When 
the  pressure  drops  to  29.40  InHg  (1.9  KgCm)  moisture  vaporizes  and  is  drawn 
out  of  the  system  by  the  vacuum  pump.  Complete  removal  of  moisture  is 
important  to  prevent  blockage  of  the  expansion  valves  with  ice.  Leak  check  the 
system as described later in this chapter. 
 
   
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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NOTE 
Due to the drop in atmospheric pressure with an increase in altitude, the normal 
vacuum reading will drop approximately 1” InHg (1 Kg/Cm) for each 1000 ft. 
 (304.8 m) of altitude. 
 
C. After  the  system  has  been  evacuated,  turn  off  both  manifold  valves,  and  then 
turn  the  vacuum  pump  off.  Allow  a  minimum  of  one  hour  to  check  for  vacuum 
leaks (if the system will not hold a vacuum, the system has a fitting leak). It may 
be  necessary  to  charge  the  system  with 1 or 2 lbs  (.45 to  .86  Kg.) of  refrigerant 
and conduct a leak check survey using an electronic leak detector.  
 
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 reduced 
compressor life. 
 
D. After the system is proven to be leak free, the system should be evacuated for a 
minimum of 1 hour before being charged with HFC R134a. 
 
E. Charging the system with 2.4 lbs. (1.1 Kg.) for Single forward evaporator, or 2.6 
lbs.  (1.2  Kg.) for Dual  forward  evaporator  of  R134a  refrigerant,  is  the  most 
accurate method of charging. This should be accomplished using the suggested 
servicing equipment called out in this chapter. 
 
F. Test-run the system after charging, to confirm the system is working properly. 
 
 
4. SERVICING PROCEDURE WITHOUT USING A SERVICE CART 
 
A. The following tools & materials will be required: 
 1. R134a Manifold Gauge Set 
 2. 3 pound bottle of R134a 
 3. Refrigerant Scale to weigh the refrigerant bottle 
 4. Vacuum Pump capable of maintaining 29in Hg of mercury at sea level 
 5. Ultra PAG oil 
 
B. Charging procedure: 
 Note that the following steps 1 through 7 are to be accomplished while the aircraft 
 and air conditioning system are “OFF”. 
  
 1. Connect the servicing lines from the manifold gauges to the servicing ports located on 
     the forward R/H side of the transmission deck. The BLUE port is for low pressure  
     (suction) and the RED port is for high pressure (discharge). 
  
 2. After the quick disconnect fittings have been connected to the servicing ports, tighten  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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     the knobs on the back of the fittings to engage the Schrader valves located inside the        
     charging ports. If the knobs are not properly tightened, the Schrader valve inside of     
     the ports will not engage. 
 
 3. To ensure there is no air or moisture in the system, use the Manifold Gauges and 
     Vacuum Pump to pull the system down on a vacuum continuously for a minimum of 1     
      hour. To perform this, connect the YELLOW line in the center of the manifold to the   
     vacuum pump. Turn the Vacuum pump on and open both valves on the charging   
     manifold until the pressure has decreased to 29.40 in Hg. 
 
 4. After 1 hour of vacuuming and while the vacuum pump is still working, close both   
     valves on the manifold gauge set and watch the High and Low pressure gauges to   
     ensure the system pressures remain constant or “vacuumed.” If the system does not   
     hold a vacuum it has a leak. 
 
 5. Once the system has been proven to be “Leak Free,” disconnect the vacuum pump   
     and connect the refrigerant bottle to the manifold gauge set. 
 
 6. Purge the line between the refrigerant bottle and manifold gauge by opening the knob 
     on the refrigerant bottle. Then, loosen the line at the manifold slightly to allow the   
     refrigerant to push the air out. This will verify that there is no air in the line. 
 
 7. Charge the system by opening the low side and high side valves which will allow   
     the initial charge of 2.0 pounds to be added. This can be measured and tracked by  
     placing the bottle on a scale. 
 
  
 Note that the following step 8 is to be accomplished while the aircraft is running at 
 100%  and the air conditioning system is “ON”. Ensure that the High side (RED) 
 is closed at all times while system is operating.) 
 
 8. Add the remainder of the required charge in 0.2 lb. increments by opening the low   
    side (BLUE) slightly to allow the refrigerant to be drawn in. Allow two minutes       
    to elapse between each addition of refrigerant. The amount entering the        
    system can be verified by monitoring the scale as the refrigerant is added. Note that  
    the compressor can be damaged if an excessive amount is added.  
     
WARNING 
If charging is to be accomplished with the compressor engaged it must be 
accomplished  through  the  LO  (BLUE)  side  only. Never  Charge  through 
the  Discharge  or  “HIGH”  (RED)  side  of  the  system  while  the 
compressor  is  running. This  may cause  severe  damage  to  the 
servicing  equipment  and  may  cause  personal  injury  or  death.  Care 
should be taken to ensure the HIGH (RED) side valve stays closed during 
this procedure and any time the system is operating.