REMOVAL/INSTALLATION AND TROUBLESHOOTING FOR AIR CONDITIONING COMPRESSORS

REMOVAL/INSTALLATION AND
TROUBLESHOOTING FOR AIR
CONDITIONING COMPRESSORS

: General

The air conditioning compressor is driven by the vehicle engine .via a ribbed or V-ribbed belt. It compresses and transports the refrigerant in the system. There are different compressor designs available

How they work:

The refrigerant is sucked in as a gas under low pressure and low temperature from the evaporator; it is then compressed and forwarded to the condenser as a gas under high temperature and high pressure.

Effects of failure:

A damaged or failed compressor can manifest itself as follows:

Loss of sealing     -
Development of noise      -
Insufficient or no cooling performance       -
Fault code is stored (automatic air conditioning)      -

Caution!

Before installing a new compressor, you must check the oil quantity and

the viscosity according to the manufacturer's instructions!

There are a number of possible causes of failure:

-    Bearing damage caused by a defective tensioner or by wear    -
Loss of sealing of the compressor shaft or of the housing        -
Mechanical damage to the compressor housing        -
Contact (electrical connections)        -
Lack of refrigerant oil        -
Lack of refrigerant         -
Solids (e.g. swarf)         -

-       Humidity (corrosion etc.)  

Troubleshooting:

Function test and pressure measurement of the system:
      - Does the compressor switch on, is the connector plug
securely in place, is there voltage?
     - Check that the drive belt is positioned correctly, undamaged,
and that there is tension.
     - Check visually for loss of sealing.
     - Check that refrigerant tubes are securely in place.
      - Compare the pressures on the high and low pressure sides.
     - Read out the fault memory.

Attention must always be paid to the following:
The entire air conditioning system must be cleaned to 100 % and the
consumables must be replaced when the compressor is replaced.

               kandi younes

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Air conditioning system with orifice tube Troubleshooting Procedures parti 2

Air conditioning system with orifice tube

Troubleshooting Procedures
parti 2

orifice tube:

Orifice tubes are used in systems that don’t use expansion valves. Like an expansion valve, the orifice tube is used to control the amount of refrigerant entering the evaporator. The diameter of the orifice tube is similarly small to that of the passage inside the expansion valve, but there is one big difference between orifice tubes and expansion valves. An orifice tube is a simple fixed device with no moving parts. It cannot vary the amount of refrigerant flowing into the evaporator the way an expansion valve can. So in systems that use orifice tubes, some additional method of refrigerant flow control must be employed. Two of the most popular methods used to do this are turning the compressor on and off at appropriate times, or cycling it, or installing a valve inside the compressor that can actually cause an adjustment to the pumping capacity of the compressor. This, of course, regulates the amount of refrigerant leaving the compressor.

4-
Low pressure:  
high

High pressure:
normal 

Outflow temperature at the centre vent  :

higher

Possible causes:
orifice tube defective (cross-section)

5-

Low pressure:  
normal

High pressure:

normal

Outflow temperature at the centre vent  :

higher

Possible causes:

 too much refrigerant oil in the
system

6-

Low pressure:  
normal to low

High pressure:

normal to low

Outflow temperature at the centre vent  :

higher

Possible causes:

lack of refrigerant

7-

Low pressure:  
low pressure and high pressure are
the same

High pressure:

low pressure and high pressure are
the same

Outflow temperature at the centre vent  :

ambient temperature

Possible causes:

lack of refrigerant, compressor
defective, fault in the electrical
system

                          kandi younes

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Air conditioning system with orifice tube Troubleshooting Procedures parti 1

Air conditioning system with orifice tube

Troubleshooting Procedures
parti 1

 Correct evaluation of the pressure manometer display is particularly important. Here are some examples:

 

orifice tube:

Orifice tubes are used in systems that don’t use expansion valves. Like an expansion valve, the orifice tube is used to control the amount of refrigerant entering the evaporator. The diameter of the orifice tube is similarly small to that of the passage inside the expansion valve, but there is one big difference between orifice tubes and expansion valves. An orifice tube is a simple fixed device with no moving parts. It cannot vary the amount of refrigerant flowing into the evaporator the way an expansion valve can. So in systems that use orifice tubes, some additional method of refrigerant flow control must be employed. Two of the most popular methods used to do this are turning the compressor on and off at appropriate times, or cycling it, or installing a valve inside the compressor that can actually cause an adjustment to the pumping capacity of the compressor. This, of course, regulates the amount of refrigerant leaving the compressor.
 
1-
Low pressure:  
 high

High pressure:
high


Outflow temperature at the centre vent  :
 higher, up to ambient
temperature
 
 Possible causes:
 engine overheated, condenser
contaminated, condenser fan
defective-incorrect direction of
rotation, system overfilled

2- 
Low pressure:  
 normal to high

High pressure:
high

Outflow temperature at the centre vent  :
 higher

 Possible causes:
 system overfilled, condenser
contaminated
3-
Low pressure:  
 normal
 
High pressure:
 normal to high

Outflow temperature at the centre vent  :
fluctuating

 Possible causes:
humidity in the system,
orifice tube occasionally blocked

       kandi younes

 

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Air conditioning systems with expansion valve Troubleshooting Procedures parti2

Air conditioning systems with expansion valve
Troubleshooting Procedures
parti2

Correct evaluation of the pressure manometer display is particularly important. Here are some examples:

 expansion valve

The expansion valve’s place in the system is at the evaporator inlet. Like any other valve, its job is to control flow; in this case, the amount of refrigerant entering the evaporator. Since system operating conditions vary (sometimes high cooling demand, sometimes low cooling demand) it is necessary to be able to adjust the amount of refrigerant entering the evaporator. For any given operating condition, if we were to allow too much refrigerant to enter the evaporator, it would get too cold, and the moisture collected on it could freeze. This would not allow the hot interior air to pass through its fins, and the refrigerant flowing inside the evaporator would not be able to absorb the heat from the air. This would eventually bring cooling to a halt. If we were to allow too little refrigerant to enter the evaporator, there may not be enough to properly absorb the interior heat, which would also result in inadequate, or no cooling. This process of varying refrigerant flow based on system cooling demand is referred to as “metering” the refrigerant into the evaporator.

Air conditioning systems with expansion valve:

6-

Low pressure:

normal, but inconsistent

High pressure:

normal, but inconsistent

Outflow temperature at the centre vent:

higher

Possible causes:

humidity in the system, defective
expansion valve

7-

Low pressure:

 fluctuating

High pressure:

fluctuating

Outflow temperature at the centre vent: 

fluctuating

Possible causes: 

expansion valve or compressor
defective

8-  

 Low pressure:

 normal to low

 High pressure:

 normal to low

Outflow temperature at the centre vent: 

higher

Possible causes:  

evaporator contaminated, lack of
refrigerant

9-  

 Low pressure:

 high

 High pressure:

 low

Outflow temperature at the centre vent:

higher, almost ambient
temperature

Possible causes:

expansion valve stuck in opened
position, compressor defective

10-  

 Low pressure:

 low

 High pressure:

 low

 Outflow temperature at the centre vent:

 higher, up to ambient
temperature

Possible causes

 lack of refrigerant

11- 

 Low pressure:

 low pressure and high pressure are
the same

 High pressure:

 low pressure and high pressure are
the same

 

 Outflow temperature at the centre vent:

 ambient temperature

Possible causes

lack of refrigerant, compressor
defective, fault in the electrical
system

         kandi younes

 

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Air conditioning systems with expansion valve Troubleshooting Procedures parti 1

Air conditioning systems with expansion valve
Troubleshooting Procedures
parti 1

Correct evaluation of the pressure manometer display is particularly important. Here are some examples:

1-

Low pressure:

 hoch

High pressure:

high

Outflow temperature at the centre vent:

higher, up to
ambient temperature

Possible causes:

engine overheated, condenser
contaminated, condenser fan
defective-incorrect direction of
rotation, system overfilled

2-

Low pressure:

normal to occasionally low

 

High pressure:

 high, occasionally

Outflow temperature at the centre vent: 

 higher, possibly fluctuating

Possible causes: 

expansion valve stuck, occasionally
closedzXDF

3-  

Low pressure:

  normal

 ">

High pressure:

 high

Outflow temperature at the centre vent:

 slightly higher

Possible causes:  

filter dryer aged, condenser
contaminated

4- 

Low pressure:

 hoch

High pressure:

normal to high

Outflow temperature at the centre vent: 

higher depending on bottleneck

Possible causes: 

line from condenser to
expansion valve narrowed

5-   

Low pressure:

 normal

High pressure: 

 normal

Outflow temperature at the centre vent:  

higher

 Possible causes: 

 too much refrigerant oil in the system

 

         kandi younes

 

   

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FAULT DIAGNOSTICS AUTO AIR CONDITIONING

FAULT  DIAGNOSTICS

AUTO AIR CONDITIONING

Testing the cooling capacity:

In addition to test and special tools, every garage requires ,respective specialist knowledge, which can be acquired by training. This applies in particular to air conditioning systems.Due to the different systems, these instructions can merely beused as guideline.

1.

 Start the engine. Switch through the ventilation stages.

Ventilation functioning?

no>>>>

2.
Check fuse
Check relays switches, wiring of all
components

yes>>>>>

3. 

Temperature to maximum cooling
Magnetic clutch activated?

no>>>>>>

4.
Check wiring/electrical connections,
power supply (+/-)
Check temperature switch/ sensor,
pressure switch
Refrigerant filling level not correct

yes>>>>

Proceed to .

5.

 Operate the system at maximum cooling performance and
medium ventilation stage for several minutes. Air outflow
temperature at the centre vent 3-8 °C.

no>>>>>>

6.
If the outflow temperature is too hot:
Heating switched off?
Interior filter OK?
Check temperature switch/ sensor,
thermostat (if available)
Check venting flaps, heating valves,
condenser ventilation

yes>>>>>

7.

 Check low pressure (LD) and high pressure (HD) at 2000
- 2500 rpm: LD: 0.5 - 3.0 bar; HD: 6.0 - 25.0 bar; for powerregulated
compressors: LD: approx. 2 bar, constant

no>>>>>

8.
See table Troubleshooting

yes>>>>>

Air conditioning
OK

                     kandi younes

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