AC/Air Conditioning — Expansion Valve Improperly MOUNTED/HEAT Sensing Tube Defective (Opens Too Wide), page 75

AC–75
AIR CONDITIONING SYSTEM – TROUBLESHOOTING

8. EXPANSION VALVE IMPROPERLY
   MOUNTED/HEAT SENSING TUBE DEFECTIVE
   (OPENS TOO WIDE)

Condition: Insufficient cooling

N04152

Symptom seen in
refrigeration system | Probable cause | Diagnosis | Remedy

• Pressure too high on both
  low and high pressure
  sides
• Frost or large amount of
  dew on piping on low
  pressure side
| • Trouble in expansion
    valve or heat sensing tube
    not installed correctly
| • Excessive refrigerant in
    low pressure piping
    ↓
  • Expansion valve opened
    too wide
| (1) Check heat sensing tube
      installed condition
  (2) if (1) is normal, check
      expansion valve
      Replace if defective

9. DEFECTIVE COMPRESSION COMPRESSOR

Condition: Does not cool

N04146

Symptom seen in
refrigeration system | Probable cause | Diagnosis | Remedy

• Pressure too high on
  low pressure sides
• Pressure too low on
  high pressure side
| • Internal leak in
    compressor
| • Compression defective
    ↓
  • Valve leaking or broken,
    sliding parts
| • Repair or replace
    compressor