DIAGNOSES — Overall System / Performance Test Diagnoses (Cont'd) — Abnormal pressure cases B, C, D
HA-35spec tablePerformance Test Diagnoses (Cont'd)
Trouble diagnoses for abnormal pressure — Cases B, C, D
High-pressure side is too high and low-pressure side is too low. [B]
Refrigerant cycleUpper side of condenser and high-pressure side are hot, however, liquid tank is not so hot.
Probable causeHigh-pressure tube or parts located between compressor and condenser are clogged or crushed.
Corrective action• Check and repair or replace malfunctioning parts. • Check compressor oil for contamination.
High-pressure side is too low and low-pressure side is too high. [C]
Refrigerant cycleHigh and low-pressure sides become equal soon after compressor operation stops.
Probable causeCompressor pressure operation is improper. ↓ Damaged inside compressor packings
Corrective actionReplace compressor.
High-pressure side is too low and low-pressure side is too high. [C]
Refrigerant cycleNo temperature difference between high and low-pressure sides
Probable causeCompressor discharge capacity does not change. (Compressor stroke is set at maximum.)
Corrective actionReplace compressor.
Both high- and low-pressure sides are too low. [D]
Refrigerant cycle• There is a big temperature difference between liquid tank outlet and inlet. Outlet temperature is extremely low. • Liquid tank inlet and expansion valve are frosted.
Probable causeLiquid tank inside is clogged a little.
Corrective action• Replace liquid tank • Check compressor oil for contamination.
Both high- and low-pressure sides are too low. [D]
Refrigerant cycle• Temperature of expansion valve inlet is extremely low as compared with areas near liquid tank. • Expansion valve inlet may be frosted. • Temperature difference occurs somewhere in high-pressure side
Probable causeHigh-pressure pipe located between liquid tank and expansion valve is clogged.
Corrective action• Check and repair malfunctioning parts. • Check compressor oil for contamination.