AirComm Corporation Airbus EC135 Cabin Air Conditioner Instructions for Continued Airworthiness User Manual

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
Revision 8 Page 35 
 
10. Removal, Replacement and Adjustment of Compressor Drive Belt 
(Figure 5 and Figure 7) 
 
Removal 
 
A. Remove  upper  engine  cowlings and  aft  engine  baffle  plate to  gain  access  to 
the compressor and mount assembly. 
B. Cut  the  safety  wire  that  secures MS509-8 jam  nut  to EC135-3020-1 
compressor adjustment assembly and loosen nut (Figure 7). 
C. Loosen  attaching  hardware  that  secures the  base  of  the  compressor 
assembly to the upper compressor mount. 
D. Turn the 412AC-3016-16 Belt Tensioning Bolt counterclockwise to loosen the 
belt tension. Remove belt from compressor pulley. 
E. Remove attaching hardware that secures the EC135-3008-1 bearing cover to 
the upper compressor mount assembly. 
F. Remove  attaching  hardware that secures the  upper  compressor  mount 
assembly to the lower mount assembly. 
G. Remove  attaching  hardware  from  the two aft outboard EC135-3012-1 brace 
assemblies and the upper compressor mount. 
H. Carefully  lift  the  upper  compressor  mount  assembly  and  provide  support to 
prevent damage. 
I. Remove belt from drive pulley. 
 
Installation/Replacement 
 
A. Install the drive belt on the drive pulley. 
 
CAUTION 
Care  should  be  taken  to  ensure  that  the  new  belt  is  not  damaged 
(nicked or cut) during installation. 
 
B. Carefully  lift  the upper compressor mount assembly  and  place onto the  lower 
mount assembly. 
C. Install belt on to compressor pulley. 
D. Install  attaching  hardware  that  secures  the  upper  compressor  mount 
assembly to the lower mount assembly. Torque bolts to 20-25 In-Lbs. 
E. Install  attaching  hardware  to  the  two  aft  outboard  EC135-3012-1  brace 
assemblies and the upper compressor mount. Torque nuts to 30-40 In-Lbs. 
F. Install  attaching  hardware  that  secures  the  EC135-3008-1  bearing  cover  to 
the upper compressor mount assembly. Torque bolts to 20-25 In-Lbs. 
G. Tighten  attaching  hardware  that  secures  the  base  of  the  compressor 
assembly to the upper compressor mount. Torque bolts to 160-190 In-Lbs. 
H. Adjust  belt  tension using the  412AC-3016-16  Belt  Tensioning  Bolt (See 
adjustment procedure below).  
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
Revision 8 Page 36 
I. Tighten  MS509-8  jam  nut  to  EC135-3020-1  compressor  adjustment 
assembly.  Torque  nut  to  40-58  Ft-Lbs  and apply  safety  wire per  MIL-P-8564, 
using MS20995C-32 safety wire.  
 
Adjustment 
 
NOTE 
Proper static belt  tension  is necessary to  insure  a proper belt 
service  life  and  to  avoid  excessive  loads  on  the  compressor,  and 
bearing assemblies. 
 
A. The proper belt  tension  is achieved  when  the  belt  deflects  .10” (2.5  mm) with 
a  9lb.  (40.0  N) load  applied  as  shown  below.  This  can  be  achieved  with  the 
aid  of  a  belt  tensioning  tool  (Gates  7401-0076  Belt  Tension  Gauge  or 
equivalent). This is the preferred method of obtaining proper belt tensioning. 
 
 
 
NOTE 
The  belt  tension  should  be  checked,  and  adjusted,  if  necessary 
after the first two hours of operation for a newly installed belt. 
 
11. Removal and Replacement of Compressor Assembly 
(Figure 5 and Figure 7) 
 
Removal 
 
A. Remove  upper  engine  cowlings  and  aft  engine  baffle  plate  to  gain  access  to 
the compressor and mount assembly. 
B. Discharge the refrigerant. Refer to Chapter 6 Servicing for instructions. 
C. Disconnect  refrigerant  hoses  from  compressor  fittings  once  refrigerant  is 
evacuated. 
D. Disconnect clutch coil wire at the TSE-16-01 connector. 
E. Cut  the  safety  wire  that  secures  MS509-8  jam  nut  to  EC135-3020-1 
compressor adjustment assembly and loosen nut (Figure 7). 
F. Loosen attaching 4X bolts that secures the base of the compressor assembly 
to the upper compressor mount. 
G. Turn the 412AC-3016-16 Belt Tensioning Bolt counterclockwise to loosen the 
belt tension. Remove belt from compressor pulley.   
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
Revision 8 Page 37 
H. Remove attaching hardware that secures the EC135-3008-1 bearing cover to 
the upper compressor mount assembly. 
I. Remove  attaching  hardware  that  secures  the  upper  compressor mount 
assembly to the lower mount assembly. 
J. Remove  attaching  hardware  from  the  two  aft  outboard  EC135-3012-1  brace 
assemblies and the upper compressor mount. 
K. Carefully  lift  the  upper  compressor  mount  assembly  and  provide  support  to 
prevent damage. 
L. Remove and retain belt from drive pulley. 
M. Remove  safety  wire  on 8X compressor pulley bolts  and  remove  bolts (Figure 
19). 
 
NOTE 
Note  the  index  marks  on  the  compressor  pulley  and  sleeve 
assembly prior to removal. 
 
NOTE 
The  clutch  plate  must  be  secured  to  prevent  the  compressor  shaft 
from  turning  to  break  the  torque  on  the  retaining  nut.  The  clutch 
plate  can  then  be  removed  with  the  use  of  a  clutch  plate  removal 
tool, or pulley puller. 
 
N. Remove  and  retain  the  compressor  clutch  retaining  nut,  and  remove  the 
clutch plate from the compressor shaft. 
O. Remove the snap-ring from the top of the compressor clutch coil, and remove 
the coil from the compressor shaft housing. 
P. Remove  the compressor  pulley  retaining  snap-ring  from  the  top  of  the 
compressor pulley sleeve. 
Q. Remove  the  sleeve  from  the  compressor  shaft  housing  using  the  EC135-
3054-1 compressor pulley / clutch removal tool. 
R. Remove  attaching  hardware  that  secures  the  compressor  assembly  to  the 
upper compressor mount. 
S. Remove compressor assembly. 
  
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
Revision 8 Page 38 
 
Figure 19:  Compressor and Pulley Assembly 
 
Installation/Replacement 
 
A. The  replacement  compressor  will  come  shipped  with  8  oz.  of  refrigerant  oil, 
however  that  level  will  need  to  be  reduced  to  account  for  oil  existing  in  the 
system.  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.  New  compressors  come 
from  Air  Comm  charged  with  8  oz.  (240  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: 
 
Example:    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  
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
Revision 8 Page 39 
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. 
 
A. Install  the  compressor  assembly  in  the upper  mount  and  install 4X 
compressor bolts. Do not tighten bolts. 
B. Install and torque the compressor clutch plate retaining nut 170 to 180 In-Lbs. 
C. Align  the  pulley  and  sleeve  assembly  index  marks and  install  attaching 
hardware. Torque 8X pulley bolts  to 70-75  In-Lbs  and apply  safety  wire per 
MIL-P-8564, using MS20995C-32 safety wire.  
 
CAUTION 
Do not allow safety wire pigtails to protrude above the height of the 8X 
pulley bolt heads or damage to the drive belt may occur. 
 
D. Install the drive belt on the drive pulley. 
 
CAUTION 
Care should be taken to ensure that the new belt is not damaged (nicked or 
cut) during installation. 
 
E. Carefully  lift  the upper compressor mount assembly  and  place onto the  lower 
mount assembly. 
F. Install belt on to compressor pulley. 
G. Install  attaching  hardware  that  secures  the  upper  compressor  mount 
assembly to the lower mount assembly. Torque bolts to 20-25 In-Lbs. 
H. Install  attaching  hardware  to  the  two  aft  outboard  EC135-3012-1  brace 
assemblies and the upper compressor mount. Torque nuts to 30-40 In-Lbs. 
I. Install  attaching  hardware  that  secures  the  EC135-3008-1  bearing  cover  to 
the upper compressor mount assembly. Torque bolts to 20-25 In-Lbs. 
J. Adjust  belt  tension  using the  412AC-3016-16  Belt  Tensioning  Bolt (See 
adjustment procedure above). 
K. Tighten  MS509-8  jam  nut  to  EC135-3020-1  compressor  adjustment 
assembly.  Torque  nut  to  40-58 Ft-Lbs  and apply  safety  wire per  MIL-P-8564, 
using MS20995C-32 safety wire. 
L. Tighten  attaching  hardware  that  secures  the  base  of  the  compressor 
assembly to the upper compressor mount. Torque 4X bolts to 160-190 In-Lbs. 
M. Reconnect clutch coil wire at the TSE-16-01 connector.  
 
 
12. Removal and Replacement of Receiver Drier (Figure 13) 
 
Removal 
 
A. Remove  LH  aft  engine  fairing  from  aircraft  to  gain  access  to  the  condenser 
assembly.  
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
Revision 8 Page 40 
B. Disconnect  refrigerant  plumbing  from  receiver  drier  fittings  once  refrigerant  is 
evacuated. 
C. Remove  attaching  hardware  securing  receiver  drier  clamps  to  condenser 
frame. 
D. Remove the receiver drier. 
 
Installation/Replacement 
 
CAUTION 
Receiver drier is capped to prevent moisture contamination. Keep caps on 
receiver drier fittings until just prior to installation. 
 
A. Install  receiver  drier  and  secure  clamps  with  retained  attaching  hardware  to 
condenser frame. 
B. Replace  all  O-Rings  before  connecting  refrigerant  plumbing  to  receiver  drier 
fittings.  Torque  refrigerant  line  connections per  fitting  tightening instructions 
pg.29. 
C. Service air conditioning system with refrigerant. 
 
13. Removal and Replacement of Bypass Valve (Figure 14) 
 
Removal 
 
A. Remove  belly  panel below  RH  seat  to  gain  access  to  the  bypass  valve 
assembly. 
B. Disconnect wiring from two each TSE-16-01 connectors. 
C. Disconnect  refrigerant  plumbing  from  bypass  valve  fittings  once  refrigerant  is 
evacuated. 
D. Remove safety  wire  and attaching  hardware  securing  bypass  valve  to the 
mounting bracket. 
E. Remove the bypass valve. 
 
Installation/Replacement 
 
CAUTION 
Flow  direction  arrow  on  bypass  valve  body  must  point  toward  the 
Aft  Evaporator.  Air  Conditioner  system  will  not  function  properly  if 
this valve is installed in reverse. 
 
A. Install bypass valve with retained attaching hardware to mounting bracket and 
apply safety wire per MIL-P-8564, using MS20995C-32 safety wire.  
E. Replace  all  O-Rings  before  connecting  refrigerant  plumbing  to bypass  valve 
fittings.  Torque  refrigerant  line  connections per  fitting  tightening  instructions 
pg.29. 
B. Connect wiring using two each TSE-16-01 connectors. 
C. Service air conditioning system with refrigerant.  
						

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14. Removal and Replacement of Binary Switch (Figure 13) 
 
Removal 
 
A. Remove  LH  aft  engine  fairing  from  aircraft  to  gain  access  to  the  condenser 
assembly and binary switch located on the receiver drier. 
B. Disconnect electrical connectors from top of binary switch. 
 
NOTE 
Use the flats provided on the top of the switch body to remove the 
switch; do not attempt to tighten or loosen the pressure switch by 
hand. 
C. Loosen switch from Schrader valve located on the receiver drier. 
D. Remove binary switch. 
 
Installation/Replacement 
 
A. Install the binary switch. 
 
NOTE 
Use  the  flats  provided  on  the  top  of  the  switch  body  to install  the 
switch,  do  not  attempt  to  tighten  or  loosen  the  pressure  switch  by 
hand. 
 
B. Tighten the  binary  switch onto the  Schrader  valve  located on  the  receiver 
drier. 
C. Reconnect the electrical connectors on the top of the binary switch. 
  
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
Revision 8 Page 42 
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 Corrective Action 
System not Cooling 
 
(Evaporator blowers still 
operating) 
System is low or empty of 
refrigerant 
 
Evacuate the system, determine the 
origin of the refrigerant leak if 
applicable, and re-charge the system. 
 Moisture or air in the system Evacuate the system, replace the 
receiver drier, and place the system 
under a vacuum for a minimum of 30 
minutes before recharging the system. 
 Compressor If the compressor has failed, it must 
be replaced. 
 Compressor drive belt If the compressor drive belt has failed 
it will need to be replaced and 
adjusted. 
 By-pass valve Check to insure the temperature 
control knob on the A/C control panel 
in the cockpit is in the full cold position 
and that there is no voltage at either 
wire connection on the bypass valve. 
If the valve remains open (by-passing 
refrigerant) the valve will need 
replacement. 
 Condenser blower motor / fan 
assembly 
Check to insure the condenser blower 
motor/fan assembly are receiving 
power, and the circuit breaker has not 
tripped; if the blowers still do not 
function, they may have failed 
internally and must be replaced. 
 Condenser Blockage Check to insure the condenser fins 
are clear and free of any blockage. 
This will cause higher than normal 
discharge pressure in the system. 
System not cooling 
 
(Evaporator blowers not 
operating) 
Air conditioner control circuit 
breaker tripped 
Reset circuit breaker; if breaker will 
not reset, check for short in circuit. 
 Forward or Aft evaporator blower 
circuit breaker tripped 
Reset circuit breaker; if breaker will 
not reset, check for short in circuit. 
 
   
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
Revision 8 Page 43 
Problem Probable Cause Corrective Action 
System not cooling 
(Evaporator blowers not 
operating) 
Forward and aft evaporator 
blower motor(s) 
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. 
Loss of cooling limited to one 
evaporator 
Expansion valve malfunction 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 
contamination 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 must be replaced. 
External moisture (Condensate) 
in the area of forward / aft 
evaporator 
Leak in evaporator, or evaporator 
drainage system 
 
 
 
 
 
 
 
 
The suction or low side of the 
evaporator refrigerant plumbing 
may be cold and will condense 
moisture. 
Water noted in the area near the 
evaporator is normally caused by 
a loose, cracked, plugged, or 
disconnected drain line. To test, 
pour water into the face of the 
evaporator checking for proper 
drainage and note any leaks. 
NOTE 
The drain line consists of a tube 
which extends from the lower 
surface of the evaporators 
through the outer contour of the 
helicopter. 
 
Cover line with a layer of 
insulating cork tape. 
Contact Air Comm Corporation Service Department for current pricing and availability of 
replacement components and parts: [email protected] 
   
						

							INSTRUCTIONS FOR CONTINUED AIRWORTHINESS EC135-200M-1 
Revision 8 Page 44 
2. System Schematics 
 
 
Figure 20 – Electrical Schematic