Maintenance of a condenser involves several steps as several components must be checked and / or cleaned. Maintenance, however, ensures the proper operation and efficiency of the system.

We need to inform our customers that preventive maintenance is essential and has many benefits. Well-maintained condensing units operate more efficiently and consume less energy.

In addition, the risk of component or equipment failure is minimized, thus reducing the frequency of system failures. As a general rule, preventive maintenance of a condenser machine should be done twice a year, however we should always consult the maintenance period provided by the manufacturer of the machine.

A symptom of a condenser maintenance failure may be overheating of the compressor. The compressor operates at a higher intensity so that the overload protection of the compressor is activated by deactivating the compressor before the desired room temperature is reached, in order to protect the engine.

If this happens often the first signs of damage are the electrical components. All electrical components have a service life based on their operating cycles. So if these cycles are every 1 minute while they should be every 15 it means that the electrical components will be damaged much earlier. Damage to electrical components is more common than damage to the compressor itself. However when the required maintenance is still not available and the condenser is still running with too much on / off at some point the compressor will also fail.

Starting a compressor is the most critical phase in its operation. Every time a compressor starts we have more intense vibrations that burden its operation. In addition, the bearings do not have sufficient lubrication and friction is created and therefore wear. So when there are many starts per 24 hours the compressor will show mechanical damage sooner.

During preventive maintenance we check that all the components of the condenser unit are securely fastened. This prevents the component from loosening but can also significantly reduce system operating noise. To remove the accumulated pollutants in the condenser we use a vacuum cleaner, compressed air or suitable chemical water soluble or not (Advanced Engineering), always protecting the environment with special covers taking care not to burden the other devices around, if any. We also check and clean the fan motor from dust and dirt with a cloth or compressed air.

If the condenser is running at a high discharge pressure despite the fact that its condenser is clean the problem could be air or the presence of non-condensing substances inside the system. Check if there is a clogged filter in the system. To make sure that there is no blockage in the filter we must check that there is no pressure difference before and after it greater than 2 psig. Empirically, if we notice freezing after the filter, it needs to be replaced. It is also useful to perform an acidity test to check for moisture and acids in the system. If it appears that they exist, all the amount of coolant should be removed and refilled with a new one after changing the filter of the machine and after achieving a satisfactory degree of vacuum in the system.

If the condenser is not clean it means that the heat exchange of the coolant with the environment is limited. This leads to less efficient operation of the compressor and a lack of subcooling. In order to respond, the system raises its operating pressure and when the problem is large, the high pressure switch is activated, stopping the operation of the system before it reaches the temperature setting we have set. The system enters a process of repeated operation / shutdown cycles without being able to reach the desired temperature for the application.

So if high operating pressures are observed the first thing we check is if the condenser is clean. If after cleaning with water we continue to have the same problem, we proceed to the chemical cleaning of the condenser. After cleaning, we measure the sub-cooling of the system to make sure that it works satisfactorily.

Subcooling is the temperature difference between the condensing temperature and the coolant temperature at the condenser outlet. The condensation temperature is found from the high operating pressure of the system using the pressure / temperature table for the specific coolant of the application. The outlet temperature of the coolant from the condenser is taken with a thermometer. If this difference is too small (less than 2 ° C) it may be a sign of a lack of coolant or other problem.

Accordingly, if this difference is too large (greater than 6 ° C) it could be an indication of system overfilling or some other problem leading to coolant build-up in the condenser element. Subcooling is necessary to avoid the presence of gas at the inlet of the expansion medium as this would reduce the efficiency and effectiveness of the system. It should be borne in mind that there is a small pressure drop across all components interposed between the condenser and the expansion valve.

Compressors are generally very reliable. However, inadequate maintenance or problems with other system components can affect the compressor and cause it to overheat. It is a good idea to measure the winding resistance with a magnifying glass to make sure there is no damage to the compressor motor. In addition, a compressor analyzer can be used for further analysis. If it is noticed soon, the overheating may not have affected the compressor. However, if the problem persists for a long time, it may need to be replaced.

It is very important to regularly and according to the instructions and standards, control of coolant losses. Early detection of leaks helps to have minimal losses to the environment by minimizing the CO2 equivalent footprint of the installation as well as the hours it will be out of operation with what this implies for the quality of the refrigerated products. Depending on the amount of refrigerant content as well as the type of refrigeration system, the number of mandatory leak tests that must be performed by the licensed and certified refrigerant undertaking maintenance is derived from current legislation.

At this point we must emphasize that any work of preventive maintenance, repair, leak control, coolant filling or cleaning must be recorded in the service book of the unit. Through this file the technician is able to draw faster and safer conclusions about any problem or malfunction.

SOURCE: "PSYKTIKOS" Magazine