How to Troubleshoot and Repair High - pressure Protection of Air - cooled Units?

2025-02-17

Treatment of High - pressure Faults
Reasons for air - conditioning high - pressure faults:

The condenser of the air - conditioning outdoor unit is dirty and blocked.
The bearing of the air - conditioning outdoor fan is jammed.
The speed regulator of the air - conditioning outdoor unit malfunctions.
The copper pipes in the air - conditioning refrigeration system are blocked by oil.
The air - conditioning condenser is too close to the louver.
The fins of the condenser of the air - conditioning outdoor unit are aged.
The number of condensers around the air - conditioning outdoor unit increases, reducing the heat - dissipation space.

For the fault reasons of high - pressure alarms, it suffices to understand the underlying cause, which is poor heat exchange in the condenser. The seven reasons listed above are just a compilation of possible causes leading to poor heat exchange.

For water - cooled units, the analysis of high - pressure alarm reasons is the same, that is, a compilation of reasons causing poor heat exchange in the shell - and - tube condenser (such as dirty shell - and - tube, insufficient cooling water, too high cooling water temperature, etc.).

The following is my analysis of high - pressure alarms in air - conditioners, hoping it will be helpful to your work:

The condenser of the air - conditioning outdoor unit is dirty and blocked.
Mainly, many units pay little attention to the operation of the outdoor unit after purchasing the equipment. Especially in units with frequent personnel transfers, they don't even know where the outdoor unit of the air - conditioner is. Therefore, high - pressure faults caused by the dirty and blocked condenser of the outdoor unit are quite common. They may not be aware that a dirty air - conditioning condenser not only consumes more energy but also affects the service life of the air - conditioning outdoor fan. After all, the air - conditioning outdoor fan operates in a high - temperature environment for a long time, which is extremely harmful to the motor.
Solution: Regularly assign specific personnel to clean the condenser of the air - conditioning outdoor unit to ensure normal heat exchange of the air - conditioning condenser. Or entrust a specialized maintenance company to provide regular and professional maintenance for the equipment.
The bearing of the air - conditioning outdoor fan is jammed.
Since the computer - room air - conditioner operates 24 hours a day throughout the year, the outdoor fan is used frequently. The aging of the outdoor fan bearing leads to the fan being jammed and not operating, which is one of the common problems.
Solution: Replace the bearing of the outdoor fan. The commonly used Ziehl - Abegg 063 fan bearing model is 6002. If the motor coil melts, it is recommended to replace the outdoor fan with a new one.
The speed regulator of the air - conditioning outdoor unit malfunctions.
The common phenomenon is that the fan speed slows down, the air - conditioning flow rate drops, and then a high - pressure alarm is triggered.
Solution: Replace the speed regulator with the same model and specification.
The copper pipes in the air - conditioning refrigeration system are blocked by oil.
Some air - conditioners have oil accumulation in the pipes due to non - standard installation. The air - conditioning refrigeration system cannot operate in a cycle, resulting in a high - pressure alarm. (It should be noted that oil accumulation in the air - conditioning pipes can sometimes also cause a low - pressure alarm. This depends on the location where the refrigeration oil accumulates in the refrigeration system and which alarm is triggered first.)
Solution: Rectify the pipes of the refrigeration system and construct according to the specifications. As an emergency measure, release the oil accumulated in the copper pipes, and the air - conditioning refrigeration operation can be restored.
The air - conditioning condenser is too close to the louver.
Solution: Appropriately remove some louvers to ensure that the air - conditioning condenser can dissipate heat normally.
The fins of the condenser of the air - conditioning outdoor unit are aged.
Solution: The best solution is to replace the condenser of the outdoor unit.
The number of condensers around the air - conditioning outdoor unit increases, reducing the heat - dissipation space.

Solution: 1. Use a spray device to cool the condenser; 2. Modify the refrigeration system by connecting a shell - and - tube condenser in series. Use the cooling water or chilled water of the central air - conditioner to cool the condenser.
At the same time, this can also reduce the noise of the outdoor unit.

Warm reminder: After dealing with the reasons for the high - pressure alarm, the indoor unit of the air - conditioner needs to reset the high - pressure protector. For example, for the following high - pressure protectors:

The high - pressure alarm of the air - conditioner is one of the most common problems in maintenance work, and the causes are multifaceted. Reasonable judgment can solve the user's urgent need as soon as possible. If the user can cooperate with the inspection, it can achieve twice the result with half the effort. The above are some of my insights on judging high - pressure alarms in my work, for reference only.

How to Troubleshoot and Repair High - pressure Protection of Air - cooled Units?1739805727892

I hope it will be helpful to you.