Possible malfunctions of the system of air-conditioning and measures on their elimination

• Why there occur malfunctions
• Diagnostics and ways of elimination of malfunctions of the refrigerating cycle
• Diagnostics of malfunctions of the refrigerating cycle details

Value of pressure on the part of low pressure is low, on an entrance aperture of expansion valve occurs hoarfrost: an exhaust outlet of the evaporator is not cold. Even at connection from the low pressure pipeline of the thermode valve of expansion valve, the temperature of connecting parts of the compressor does not change.

Reason:

Blocking or malfunction of expansion valve.

Way of elimination:

Regulation and replacement of expansion valve.

Values of pressure on the low and high pressure part are low: in an observation port there is a plenty of foam, the temperature from both sides of the pipeline of high and low pressure is almost identical.

Reason:

There is not enough gaseous refrigerant.

Way of elimination:

Though depending on weather and temperature there is a change of pressure if there is no internal blocking of the system, high and low pressure accordingly approximately make 14 kg/sm² and 1,5–3 kg/sm² in summer. When values of pressure are lower than specified, it is explained by insufficiency of a gaseous refrigerant. Therefore, after checking and correction of a place of gas outflow, there occurs refueling by the refrigerant up to the specified value.

Value of pressure on the high pressure part is low: exhaust outlet of expansion valve is not in a cold condition; the manometer of low pressure shows vacuum.

Reason:

Outflow of gas of a cylinder of expansion valve thermode.

Way of elimination:

Replacement of unit of expansion valve.

Value of pressure on the low pressure part is high. If to stop the compressor during a cycle, for the short time (within 1 minute) indications of manometers of high and low pressure become identical.

Reason:

Damage of the head sealant , damage of the high pressure valve.

Way of elimination:

Replacement of the compressor and performance of works on filling with the refrigerant.

Too low value of pressure on the part of low pressure.

Reason:

Defect of the compressor valve lining (At a stop of the compressor, high and low pressure manometers specify identical value of pressure).

When the valve of expansion valve thermode does not completely adjoin.

Way of elimination:

Clearing of the valve or replacement of the compressor.

The valve of the pipeline thermode of low pressure is set up so that it is densely adjoined.

The difference of temperatures of inlet and outlet of a tank of the receiver - dehydrator is big.

Reason:

Blocking of a tank of the receiver - dehydrator.

Way of elimination:

Replacement of a tank of the receiver - dehydrator.