Case Study: Central Air Conditioner Repair


Air-conditioning related knowledge

  1. Air conditioner:

The air conditioner is a device that directly provides treated air to a room or other confined areas. It mainly includes refrigeration systems for refrigeration and dehumidification, air circulation and purification devices, heating and ventilation devices, etc. The main function of the air conditioner is to filter, cool, and dehumidify the indoor air. (Some also have the function of heating and replacing fresh air) to realize automatic adjustment of indoor temperature. According to different functions, air conditioners can be divided into single cooling type, heat pump type, and electric auxiliary heating type.

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  1. Inverter air conditioner:

A new type of air conditioner that can continuously adjust the frequency or speed of the compressor within a certain range to change the flow rate of the refrigerant, and exert the ability to best match the environmental conditions, and automatically adjust the output. Inverter air conditioners use digital signal processing and analog control combined with artificial intelligence control. Compared with ordinary air conditioners, inverter air conditioners have the advantages of rapid cooling and heating, high efficiency and energy saving, comfort and reliability, intelligent defrosting, large dehumidification capacity, ultra-quiet, and wide-voltage operation.

The difference between an inverter air conditioner and a fixed frequency air conditioner:

  • The inverter air conditioner starts to run at high power, reaches the set temperature quickly, maintains low power, and the room temperature is balanced, so the cooling and heating are rapid, power saving, and room temperature fluctuations are small.
  • The fixed frequency air conditioner operates at a fixed power and maintains the indoor temperature through frequent switching on and off, so the cooling and heating speed is slow, which has a large impact on the home power grid and large room temperature fluctuations.

The difference between digital DC air conditioner and air conditioner:

The AC air conditioner changes the compressor’s power supply frequency, thereby changing the compressor’s working speed and power supply frequency from 10HZ to 150HZ;

The DC air conditioner changes the compressor’s power supply voltage, thereby changing the compressor’s working speed, and the power supply voltage is 150V to 260V.

  1. Representation of air conditioner model:

The naming method for domestic air conditioners is as follows: KFR(d)50LW/T(D BP JXF) K-air conditioner F-split R-heat pump heating type D-auxiliary electric heating 50-cooling/heating capacity L-structure type W-outdoor Machine T-development model D-DC BP-frequency conversion J-ion dust removal X-two-way air exchange F negative ion (L? In the structure type code: “L”-cabinet type, floor-standing type; “G”-wall-mounted type; C”- Window type; “N”-built-in type; “F”-duct type; “Q”-embedded type; “D”-ceiling type)

  1. The cooling capacity/heating capacity of the air conditioner:

1) During the cooling operation of the air conditioner, the heat discharged from the enclosed room per unit time is called the cooling capacity of the air conditioner.

2) When the air conditioner is in the heating operation, the heat released from the enclosed room per unit time is called the heating capacity of the air conditioner.

3) Each square meter of air conditioner requires 150W cooling capacity: the formula for calculating room area using the air conditioner is thus derived:

Cooling capacity/150W=△ △+2=□ △-2=0

“△” is the area to adapt to the room. “□” is to adapt to the maximum area. “0” is to adapt to the smallest area. For example: KFR-2601GW/BP Cooling capacity: 2600W 2600/150=17 17+2=19 17-2-15

That is, the applicable area of ​​the air conditioner is: 15-19?, and the number of horses of the air conditioner is also derived from this.

Classification of air conditioners according to cooling capacity:

1P: 2300W-2500W 1.5P: 3000W-3600W 1.25P: 2600W-2800W

2P: 4000W-5200W 3P: 6500W-7200W 2.5P: 5800W-6200W

5P:1200W 10P:2400W

Power consumption:

1P: around 900W 1.5P: around 1300W 2P: around 1800W

3P: about 2800W 5P: about 5000W 10P: about 10000W

The general air conditioner voltage is 220V, 3P has 220V and 280V; 220V is suitable for home use; 380V is power electricity and is suitable for commercial use

Generally 5P and 10P are commercial machines, and the codes for 380V power are generally: “3”, “S”

Air conditioner applicable area:

1P: 11-17? 1.5P: 18-25? 2P: 30-33? 1.25P: 18-23? 3P: 40-45? 5P: 60? Around 10P: 50?

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The certification mark on the air conditioner

Most of the air conditioners sold on the market are attached with quality certification marks. Due to different certification agencies, these marks are also diverse and different. The following are common air conditioner quality certification marks:

  1. AS mark: The Australian Standards Association (SAA) is a mark used for electrical and non-electrical products. It is protected by Commonwealth Commercial Regulations and is universally used internationally.
  2. BEB mark: the inspection qualification mark of the British Underwriters Laboratory. This sign is common in many countries in the world and is authoritative.
  3. UL mark: Underwriters Laboratories certification mark.
  4. JIB mark: The mark issued by the Japan Organization for Standardization (JIB) for its qualified electrical products and textiles.
  5. CECC mark: European electrician certification mark.

When consumers buy air-conditioning products, in addition to purchasing based on brand, performance, specifications, etc., various quality certification marks can also be used as references. Knowing some knowledge of certification marks is very important for consumers to purchase products. The benefits.

Basic methods for judging common failures of central air-conditioning

Today, Canada Energy Solution will tell you about several common failures of central air-conditioning and the corresponding maintenance methods. I hope it will help everyone to use the central air conditioner every day, let’s take a look!

  1. Reasons and solutions for indoor noise greater than design requirements. :

Refrigeration system: Observe whether there are cracks, breakages, frosting, and condensation in each pipeline of the refrigeration system; whether there is friction between the refrigeration pipelines, the pipeline, and the shell, especially the welding place of the refrigerant pipeline, Whether there is any leakage at the joint connection, where there will be oil stains (there is a certain amount of refrigerating oil in the refrigeration system), you can also use a clean soft cloth or soft paper to wipe the pipe welded joints and the joints to observe whether there are any oil stains. Determine whether there is a leak.

Electrical system: Observe whether the fuse of the electrical system is blown, whether the insulation of the electrical wire is intact, whether the circuit board is broken, whether the connection is loose, etc. In particular, whether the electrical connection is in good contact, and the wiring screws and connectors are easily loosened to cause poor contact.

Ventilation system: Observe whether the air filter, heat exchanger coils, and fins are too dusty; whether the air inlet and outlet are unblocked; whether the fan and fan blades are operating normally; whether the wind power is normal, etc.

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  1. Reasons and solutions for dead ends caused by uneven indoor wind speed distribution:

Turn on the power and listen to whether the air conditioner compressor is running normally, whether there is any abnormal sound, whether the fan is running, whether there is noise, whether the noise is too loud, etc. During the operation of the air conditioner, under normal circumstances, the vibration is slight and the noise is small, generally below 50dB. If the vibration and noise are too loud, the possible reasons are:

1) Improper installation. If the size of the bracket is not consistent with the unit, the fixing is not tight, or the damping rubber or foam pads are not added, the vibration and noise of the air conditioner will increase during operation. Especially when it is just started and stopped.

2) The compressor vibrates abnormally. The base is not properly installed, the feet are not level, the anti-vibration rubber or the anti-vibration spring is poorly installed, or the anti-vibration effect is not good. If there is a malfunction in the compressor, such as a broken valve, liquid hammer, etc., abnormal sounds will also be emitted.

3) The fan hits. Poor installation or deformation of fan blades can cause a crashing sound. The fan may collide with the wall shell and the chassis, the axis of the fan moves, and the blades lose their dynamic balance and will make a crashing sound; if there are foreign objects in the fan, the blades will also make a crashing sound when they collide with it.

  1. Reasons and solutions for the measured air volume of the system to be less than the designed air volume:

Touch the relevant parts of the air conditioner to feel the heat, cold, and tremor, etc., which is helpful to judge the nature and location of the fault. Under normal circumstances, the temperature of the condenser gradually decreases from top to bottom, and the temperature of the lower part is slightly higher than the ambient temperature.

If the entire condenser is not hot or the upper part is slightly warm, or although it is hot there is a significant difference in temperature between the upper and lower adjacent pipes, it is abnormal. The evaporator will feel cold and sticky if you put a finger dipped in water on the surface of the evaporator under normal conditions. Under normal circumstances, the capillary tube at the dryer and outlet should have a warm feeling (slightly higher than the ambient temperature, and basically the same as the temperature of the pipe at the end of the condenser), if it feels slower than the ambient temperature or there is dew condensation on the surface and there is a temperature difference in each section of the capillary Etc. are not normal. The temperature of the suction pipe at a distance of 200mm from the compressor should be similar to the ambient temperature under normal conditions.

  1. Reasons and solutions for the measured air volume of the system greater than the designed air volume:

In order to accurately determine the nature and location of the fault, it is often necessary to use instruments and meters to check and measure the performance parameters and status of the air conditioner. For example, use a leak detector to check for refrigerant leakage; use a multimeter to measure whether the power supply voltage, the ground voltage of each terminal and the operating current meet the requirements, and the air conditioner controlled by a computer should also measure whether the potential of each control point is normal.

  1. The total air supply volume of the system is inconsistent with the total air intake volume. Reasons for the big difference and solutions:

Most of the results obtained through the above-mentioned inspection and maintenance methods can only reflect a certain partial state. The various parts of the air conditioner are related to each other and affect each other. One failure phenomenon may have multiple causes, and one cause may also cause multiple failures. Repair a central air conditioner requires a lot of experience and knowledge.

Therefore, it is necessary to conduct a comprehensive comparative analysis of local factors, so as to fully and accurately determine the nature and location of the fault. If the refrigeration system leaks or is blocked, it will cause the refrigeration system pressure to be abnormal and cause the refrigeration (heating) capacity to drop. However, leakage will inevitably lead to the insufficient refrigerant, which will reduce both the high and low pressures; while the blockage occurs in the high-pressure part, there will be the high-pressure rise and low-pressure drop. Therefore, it can be distinguished according to the failure phenomenon to determine whether it is leaking or plugging.

The above is the guide on how to repair the common minor faults of the central air conditioner introduced by the professional maintenance staff of Canada Energy Solution central air conditioner in Toronto. I hope it will be helpful for you to understand how to repair the central air conditioner. If you need to repair the central air conditioner, please contact us.