Page 1310 - Foton Workshop Manual - Aumark (BJ1099)

41-30 HEATING AND AIR CONDITIONING - REFRIGERANT

Symptom Possible Cause Diagnostics Action

• Check and replace the
•Overly refrigerant in the
High pressure at both Defective expansion low pressure pipe expansion valve.
high and low ends. Frost valve •Dirty or blocked expansion • Ensure the refrigerant
or dew at the low end. volume in the system
valve.
meets the standard.

• Defective compressor (condition: no cooling)

Symptom Possible Cause Diagnostics Action
• Defective compressor. •Repair or replace the
Overly high at the low Internal leakage in •Leakage in the compressor.
end and overly low at compressor damaged valve or •Eliminate the system
the high end.
moving part. leakage.

2. Check for leakage with soap solution
(a). When checking for major leakage at the connection of the cooling pipe, spray some
soap solution around the connection and look for bubbles if any. Though it is simple
and convenient, it couldn't detect minor leakage.
3. Check for leakage with non-selective detector
(a). It detects all kinds of liquid or gas leakages without taking account of the chemical
components of the tested substance. It is easy, stable and cost-effective. However,
it is not applicable to large areas.
4. Check for leakage with halogen leak detector
(a). With specific sensors, it detects the compounds containing minor volume of F, Cl, Br
and I in the air, regardless the intervention of other substances. It is highly sensitive
and effectively minimizes detection errors. In case of large areas, the min. detection
threshold is 5g/year; and for spot detection, it is 1.5g/year (i.e., it can detect a
leaking point with the leakage volume of 1.5g a year).

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