1. INSPECT REFRIGERANT VOLUME
(a) Check the sight glass on the cooler refrigerant liquid pipe A.
Test conditions:
Item |
Symptom |
Amount of refrigerant |
Corrective Actions |
1 |
Bubbles exist | Insufficient* | (1) Check for gas leakage and repair if necessary (2) Add refrigerant until bubbles disappear |
2 | No bubbles exist | Empty, insufficient or excessive | Refer to 3 and 4 |
3 | No temperature difference between compressor inlet and outlet | Empty or nearly empty | (1) Check for gas leakage with gas leak detector and repair if necessary (2) Add refrigerant until bubbles disappear |
4 | Considerable temperature difference between compressor inlet and outlet | Proper or excessive | Refer to 5 and 6 |
5 | Immediately after air conditioning is turned off, refrigerant clears | Excessive | (1) Discharge refrigerant (2) Remove air and supply proper amount of purified refrigerant |
6 | Immediately after air conditioning is turned off, refrigerant foams and then becomes clear | Proper |
- |
*: Bubbles in the sight glass with ambient temperatures higher than usual can be considered normal if cooling is sufficient.
2. INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET
(a) This is a method in which the trouble is located by using a manifold gauge set. Read the manifold gauge pressure when these conditions are established.
Test conditions:
Gauge reading: Low pressure side: 0.15 to 0.25 MPa (1.5 to 2.5 kgf/cm2) High pressure side: 1.37 to 1.57 MPa (14 to 16 kgf/cm2)
Symptom |
Probable cause |
Diagnosis |
Corrective Actions |
During operation, pressure on low pressure side cycles between normal and vacuum | Moisture in refrigeration system
freezes at expansion valve orifice,
causing a temporary stop of cycle. However, when it melts, normal state is restored. |
|
|
Symptom |
Probable cause |
Diagnosis |
Corrective Actions |
|
Gas leakage in refrigeration system |
|
|
Symptom |
Probable cause |
Diagnosis |
Corrective Action |
|
Refrigerant flow is obstructed by dirt in the receiver | Receiver is clogged | Replace condenser |
Symptom |
Probable cause |
Diagnosis |
Corrective Actions |
|
|
Refrigerant does not circulate |
|
Symptom |
Probable cause |
Diagnosis |
Corrective Actions |
|
|
|
|
Symptom |
Probable cause |
Diagnosis |
Corrective Actions |
|
Air in system |
|
|
Symptom |
Probable cause |
Diagnosis |
Corrective Actions |
|
Trouble in expansion valve |
|
Check expansion valve |
Symptom |
Probable cause |
Diagnosis |
Corrective Actions |
|
Internal leak in compressor |
|
Repair or replace compressor |
Gauge readings (Reference)
Starting & charging
SERVICE DATA
2AZ-FE
3MZ-FE
TORQUE SPECIFICATION
2AZ-FE
3MZ-FE
...