Indication:

• This may cause the refrigeration compressor to overheat, with a high discharge pressure and normal condensing temperature.
• There are possibilities of small air bubbles in the liquid sight glass of the condenser.
• The condensing pressure of the refrigerant in the condenser may be high.
• If there is excessive air, it may reduce the cooling capacity of the system, making the compressor run for an extended period of time.
• It may cause the gauge pointer of the condenser to jump indefinitely.

Causes:

• During charging, air may enter into the system.
• If Freon-12 is used, air may leak into the suction line because the working pressure of the Freon-12 refrigerant is less than the atmospheric pressure.

Action:

• Air in the system can be removed by collecting the system gas in the condenser, leaving the condenser cooling water on and venting out the air from the condenser because air will not be condensed in the condenser but remains on top of the condenser above the liquid refrigerant.
• Connect the collecting cylinder to the purging line of the condenser, open the valve, and collect air in the cylinder.
• After purging the air from the system, don't forget to shut the purging valve.
• Check the level of the refrigerant in the system. If required, charge the system with fresh refrigerant.
• Restart the compressor with all safety precautions.

Indication:

• This normally comes with the ingress of air in the system. Moisture may freeze at the expansion valve, giving some indication of undercharging.
• It will contribute to the corrosion in the system.
• It may cause lubrication problems and breakdown of the lubricating oil in the refrigerant compressor.

Action:

• Renew silica gel in case of minor moisture.
• Collect refrigerant and remove all air and moisture by vacuum pump If the amount is huge.

Indication:

• The compressor is running hot, and the performance of the compressor falls off due to the high superheat temperature at the suction side of the compressor.
• The suction and discharge pressure of the compressor is low.
• Large vapour bubbles in the liquid sight glass.
• Low gauge readings in the condenser.
• The ammeter reading for the compressor motor is lower than normal.
• Rise in room temperature, which is to be cooled.
• Compressor Is running for an extended period.

Causes:

• Leakage of refrigerant at the shaft seal, flange couplings, valve gland, etc.
• Expansion valve may be blocked at the strainer.
• Partial blockage of the refrigerant at the filter, drier or evaporator may cause undercharging.

Action:

• Identify and rectify the leakage of refrigerant from the system.
• Clean the filter and drier.
• Charge the system with fresh refrigerant as required.

Indication:

• The liquid level in the condenser is too high (high condenser gauge reading). This will reduce the available condensing surface, with a corresponding increase in the Saturation temperature and pressure.
• The high-pressure switch of the refrigerant compressor activates and stops the compressor.
• The suction and the discharge pressures are high.

Causes.

• It may be due to the reason that excessive refrigerant has been charged in the system.
• Air In the system may also cause an overcharging indication.

Action:

• Remove the refrigerant from the system. This is done by connecting a cylinder to the liquid line charging valve, starting the compressor, and then operating the charging valve.
• Purge the air from the system and maintain effective cooling.
• Remove ice from the regulator by using any of the defrosting methods.