Why air-cooled chiller has high pressure alarm?

In hot summer, many air-cooled chillers have high pressure alarm,especially in areas with relatively high temperatures which can be above 45℃, such as Saudi Arabia, the United Arab Emirates, Iraq and so on.

General air-cooled chiller is equipped with a full set of protection devices, when the chiller appears high pressure alarm, it will automatically start the protection device, and the corresponding fault indicator light will be lit.

The high pressure alarm of the air-cooled chiller is triggered by the poor cooling effect of the condenser.If this problem is not fixed and keep running the chiller at high pressure for a long time, it will cause the current to be too large and burn the compressor.

The reasons for the chiller high pressure alarm are as follows:

1. Air-cooled chiller’s condenser rely on fans to dissipate heat.When the ambient temperature is above 42 degrees, the heat dissipation of the condenser is poor, that is, the heat generated by the refrigerant circulation cannot be taken away by the fan.

2. The condenser is dirty and blocked, which will also cause poor heat dissipation and lead to high pressure alarm.

Solution:

1. Check whether the fan works properly.

2. Make sure there’s good ventilation to exhaust hot air smoothly.

3. If the ambient temperature is higher than 42 degrees, use a fan or cooler to cool down the temperature around.

4. Periodically remove the air filter to clean the fins or clean the fins with high-pressure air.

5. If the ambient temperature is around 42 ℃, need to increase the condenser size to improve heat dissipation efficiency.Normally, we will increase size to 25% for chiller using refrigerant R22, R407c, R410a.

If ambient temperature higher than 45 ℃, we suggest to design the chiller with R134a which can be used at ambient temperature of 50 ℃.The disadvantage is that the cost is relatively high, because its refrigeration efficiency is only 65% compare with other refrigerants, in order to achieve the same cooling capacity, you must use a larger compressor.

P.S. The installation of air-cooled chiller should choose the right location to ensure that the installation environment is well ventilated.