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

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
Revision 11  Page 64 
 
CHAPTER 8 
TROUBLESHOOTING 
 
1. SYSTEM TROUBLESHOOTING 
Prior to troubleshooting a defective system, it is advisable to conduct a visual 
inspection for general condition, and obvious signs of damage or failure. 
 
The following matrix lists the easiest checks, and the most likely problems. 
 
Problem Probable Cause Solution 
System not Cooling 
(Evaporator blowers still operating) 
a. System is low or empty of 
refrigerant. 
 
a. Evacuate the system, determine the 
origin of the refrigerant leak, and re-
charge the system as prescribed in 
chapter 6. 
b. Moisture or air in the system. b. Evacuate the system, Replace the 
receiver / drier, and place the 
system under a vacuum for a 
minimum of 45 minutes before 
recharging the system. 
c. Compressor c. If the compressor has failed, it must 
be replaced, as per chapter 7. 
d. Compressor drive belt d. If the compressor drive belt has 
failed it will need to be replaced. 
Replace and adjust compressor 
drive belt as per chapter 7. 
e. By-pass valve e. Check to ensure the temperature 
control knob on the A/C control 
panel in the cockpit is in the full cold 
position, and the temperature 
control circuit breaker has not 
tripped. If the valve remains open 
(by-passing refrigerant) the valve 
will need replacement, as per 
chapter 7. 
f. Condenser blower motor / fan 
assembly. 
f. Check to ensure the condenser 
blower motor / fan assembly are 
receiving power, and the circuit 
breakers have not tripped. If the 
blowers still do not function, they 
may have failed internally and must 
be replaced as per chapter 7. 
g. Condenser Scoop Door & Scoop 
Door Actuator 
g. Check to ensure the condenser 
scoop door is fully extended when 
the air conditioner is running. If the 
scoop door is closed or not fully 
extended the scoop actuator circuit 
breaker may have tripped, or the 
scoop door actuator may have 
failed, and must be replace as per 
chapter 7. 
System not cooling 
(Evaporator blowers not operating) 
h. Air conditioner control circuit 
breaker tripped. 
h. Reset circuit breaker. If breaker will 
not reset, check for short in circuit. 
i. Forward or Aft evaporator 
blower circuit breaker tripped. 
i. Reset circuit breaker. If breaker will 
not reset, check for short in circuit.  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
Revision 11  Page 65 
 
Problem Probable Cause Solution 
System not cooling 
(Evaporator blowers not operating) 
j. Forward and aft evaporator 
blower motor(s) 
j. Check for power to the 
motor(s), and for the free 
movement of the blower 
wheel. If the motor shaft does 
not turn smoothly the motor 
must be replaced, as per 
chapter 7. 
Loss of cooling limited to one 
evaporator. 
k. Expansion valve malfunction. k. If cooling is lost in only one of 
the evaporators, and the 
blowers continue to function, it 
is most likely a blockage at the 
expansion valve orifice. This is 
most often caused by dirt in 
the system forming a blockage 
as the refrigerant passes 
through the valve. Evacuating 
the system and changing the 
receiver drier should cure this 
problem. If the above actions 
do not resolve the problem, 
the evaporator assembly 
should be replaced 
External moisture (Condensate) in 
the area of forward / aft evaporator 
l. Leak in evaporator, or 
evaporator drainage system. 
l. If water is noted in the area 
near the evaporators. This is 
normally caused by a loose, 
cracked, plugged, or 
disconnected drain line. 
NOTE 
       The drain line consists of a 
tube which extends from the 
lower surface of the 
evaporators through the outer 
contour of the helicopter. 
(Contact Air Comm Corporation Service Department for current pricing and availability of 
replacement components and parts). 
 
  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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Figure 27:  General Arrangement – Air Conditioning System Installation. 
 
407EC
-614 & 616
 
Evaporator Instl
 
407EC
-802 & 804
 
Electrical Instl
  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
Revision 11  Page 67 
 
Figure 28:  Air Conditioning System Electrical Schematic (Dual Forward 
Evaporator System)  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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Figure 29:  Electrical Schematic – Temperature Control Circuitry & Transient 
Suppression Circuitry / Wiring Schematic (Dual and Single Forward Evaporator Systems)  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
Revision 11  Page 69 
 
 
Figure 30:  Refrigerant Plumbing Schematic (Dual Forward Evaporator System) 
Through 1st Quarter 2015  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
Revision 11  Page 70 
 
 
 
 
 
 
Figure 31:  Refrigerant Plumbing Schematic (Dual Forward Evaporator System) 
After March 1, 2015 
 
    
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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Figure 32:  Air Conditioning System Electrical Schematic (Single Forward 
Evaporator System)  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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Figure 33:  Refrigerant Plumbing Schematic (Single Forward Evaporator System)  
						

							AIR CONDITIONER SERVICE MANUAL 407EC-200M-2 
 
 
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APPENDIX A 
Weight and Balance Information 
 
Weight breakdown – Bell 407 Air Conditioner System: 
 Ref. Drawings 407EC-201, 407EC-202, 407EC-203 
 
NOTE 
The weight change between the 407EC-201, 407EC-202, and the 407EC-
203 installations is negligible.  
 
Dwg 407EC-201-1 Single LH Fwd Evaporator with 407EC-620-1 Panasonic Motor Install 
Dwg 407EC-201-2 Dual Fwd Evaporator with 407EC-620-1 Panasonic Motor Install 
Dwg 407EC-201-3 Single RH Fwd Evaporator with 407EC-620-1 Panasonic Motor Install 
 
  Wt (lbs) Arm (in) M (in-lb 
Total (-1 & -3 Single Fwd Evap) 94.57 138.0 13052 
 
Total (-2 Dual Fwd Evaps) 104.77 126.5 13256 
 
Dwg 407EC-201-2 Dual Fwd Evaporator with 407EC-620-2 High Output Advanced 
Industries Motor Install  
     Wt (lbs) Arm (in) M (in-lb 
Total (-2 Dual Fwd Evaps) 108.74 128.5 13978 
 
Dwg 407EC-201-1   Single LH Fwd Evaporator with 407EC-622-1 FASCO Motor Install 
Dwg 407EC-201-2 Dual Fwd Evaporator with 407EC-622-1 FASCO Motor Install 
Dwg 407EC-201-3 Single RH Fwd Evaporator with 407EC-622-1 FASCO Motor Install 
 
  Wt (lbs) Arm (in) M (in-lb) 
Total (-1 & -3 Single Fwd Evap) 95.27 138.3 13179 
 
Total (-2 Dual Fwd Evaps) 105.47 126.9 13383 
 
 
Dwg 407EC-202-1   Single LH Fwd Evaporator with 407EC-622-1 FASCO Motor Install 
Dwg 407EC-202-2 Dual Fwd Evaporator with 407EC-622-1 FASCO Motor Install 
Dwg 407EC-202-3 Single RH Fwd Evaporator with 407EC-622-1 FASCO Motor Install 
 
  Wt (lbs) Arm (in) M (in-lb) 
Total (-1 & -3 Single Fwd Evap) 95.27 138.3 13179 
 
Total (-2 Dual Fwd Evaps) 105.47 126.9 13383