The split system does not work after a power surge. We repair the air conditioner yourself: diagnostics and troubleshooting. Replacing the control board
Air conditioner troubleshooting
If the air conditioner operates abnormally, please refer to the following table from the air conditioner operating instructions. This can save you time and avoid unnecessary expenses.
| Problem | Solution |
|---|---|
|
Air conditioner doesn't work |
Check the power status, and then turn on the air conditioner again. |
|
Temperature adjustment does not work |
Check to see if you have selected Fan/Turbo mode. In these modes, the desired temperature is set automatically and you cannot adjust the temperature. |
|
No cold/warm air coming from the air conditioner |
Check if the set temperature is higher (in Cooling mode)/lower (in Heating mode) than the existing temperature. Click the button Temp(Temperature) +
or –
on the remote control to change the set temperature. |
|
Air flow adjustment does not work |
Make sure you select Auto / Dry / mode. In these modes, the desired temperature is set automatically and you cannot adjust the temperature. |
|
Fan speed control does not work. |
Make sure you select Auto / Dry / Turbo / . In these modes, the fan speed is set automatically and you cannot adjust the fan speed. |
|
The remote control does not work. |
Check to see if the batteries are dead. |
|
Timer function cannot be set |
Check if you pressed the button Set(Set) on the remote control after setting the time. |
|
The indicator flashes continuously. |
Click the button Power(Power) or unplug/turn off the optional power switch. If the indicator continues to flash, contact your service center |
|
Odors enter the room during operation. |
Check whether the device is operated in a smoky place. Ventilate the room or turn the air conditioner to Fan mode for 1 ~ 2 hours. (We do not use components in the conditioner that emit an unpleasant odor.) |
|
The message Error appeared. |
If the indoor unit indicator is flashing, contact your nearest service center |
|
There was noise. |
Depending on the mode in which the air conditioner is used, noise may be heard if the refrigerant flow changes. This is fine. |
|
Smoke is coming from the outdoor unit. |
Since this cannot be a fire, it may be steam generated when the outdoor unit heat exchanger defrosts in Heat mode in winter. |
|
Water is dripping from the connecting pipes of the outdoor unit. |
Water can form due to temperature differences. This is fine. |
Indoor unit filters are dirty
Filter contamination impairs the airflow of the heat exchanger, which leads to a decrease in the air conditioner's performance in terms of cold or heat. In addition, disruption of the system operation can lead to freezing of copper pipelines. When you turn off the air conditioner, the ice will begin to melt and water will drip from the indoor unit.
Severe contamination of the filters can lead to clogging of the drainage system with dust lumps and disruption of normal condensate drainage.
Filters should be cleaned once every two to three weeks, and more often if the indoor air is highly dusty. To clean the filters, they are washed in warm water and dried, or cleaned with a vacuum cleaner. The service life of fine air filters used in some air conditioner models either as an option or as standard (these filters cannot be restored) depends on air pollution, but in city conditions it rarely exceeds 3...4 months. Cleaning and changing filters is not included in the standard warranty service and, like cleaning or changing bags in a vacuum cleaner, must be performed by the user.
Contamination of the outdoor unit heat exchanger
One of the most typical types of heat exchanger contamination is its clogging with poplar fluff, which leads to disruption of the heat removal mode, overheating of the compressor and its failure. According to experts, about a third of climate system failures occur for this reason.
The heat exchanger is cleaned before starting to operate the air conditioner after the winter season, and during operation - periodically, as it gets dirty. In addition to poplar fluff, the heat exchanger can be clogged by fallen leaves, street debris, etc. When cleaning the heat exchanger, care should be taken not to damage the thin fin plates. To clean and straighten the ribs if they are damaged, you can use a special tool, which is a set of several “combs” for the ribs with different spacing between the plates. Poplar fluff, dust and other contaminants are blown out with a stream of compressed air.
Normalized refrigerant leakage
The second most common cause of air conditioner failure is a normal refrigerant leak. The amount of standardized leakage is 6...8% per year of the mass of refrigerant charged into the circuit. This leakage always occurs, even with the best-quality installation of the system, and is an inevitable consequence of the presence of joints in the connecting pipes. To compensate for the normalized leakage, it is necessary to refill the air conditioner with refrigerant every 1.5...2 years. Otherwise, the amount of refrigerant in the circuit may fall below the minimum permissible level, which will lead to overheating of the compressor and its seizure.
To minimize refrigerant leakage, do not use excessive force when tightening the nuts of butt joints, as overtightening can lead to damage to the joint. The table shows the recommended torque values when tightening nuts on pipes of various diameters.
| Tube diameter, inches | Torque, kg cm |
|---|---|
| 1/4 | 160 - 200 |
| 3/8 | 350 - 450 |
| 5/8 | 450 - 550 |
| 3/4 | 550 - 650 |
The first sign of a decrease in the amount of refrigerant in the circuit is the formation of frost or ice on the union connections of the outdoor unit, as well as insufficient cooling or burning of the air in the room. Normally, the difference in air temperature at the inlet and outlet of the indoor unit after about 15 minutes of operation of the air conditioner should be at least 8...10 °C in cooling mode and at least 12...14 °C in heating mode.
Air conditioners usually provide both the output of a message about a decrease in the amount of refrigerant among other fault codes, and the activation of protective actuators. In air conditioners produced in the 1980-1990s, to turn off the product when there was a lack of refrigerant, a low pressure switch was used, which was activated when there was an abnormal pressure drop in the circuit and turned off the system. Most manufacturers are now moving to electronic control systems that measure temperature at key system control points and/or compressor operating current. Based on these data, all operating parameters of the climate system are calculated, including refrigerant pressure.
A refrigerant leak is dangerous for the following reasons:
- the compressor of the outdoor unit is cooled by the flow of refrigerant, therefore, due to a decrease in the density of the refrigerant, the compressor overheats;
- the temperature of the discharge gas increases, which may cause damage to the 4-way valve by hot gas;
- The compressor lubrication system is disrupted, and oil is carried away into the heat exchanger.
- Signs of a refrigerant leak include:
- darkening of the compressor insulation;
- periodic activation of the compressor heat protection relay;
- burning of insulation on the compressor discharge tube;
- darkening of the oil, appearance of a burning smell;
- positive result when testing the oil for acidity.
Incorrectgas stationrefrigerant circuit
One of the main reasons for abnormal operation of air conditioners and failure of compressors is improper filling of the refrigerant circuit. Moreover, if the lack of refrigerant in the circuit can be explained by various types of leaks, then overcharging, as a rule, is a consequence of erroneous actions of service personnel.
For systems that use a thermostatic valve (TEV) as a throttling device, the best indicator indicating the normal refrigerant charge is the subcooling temperature.
The subcooling temperature Т1 (or simply subcooling) is defined as the difference Т1 = Тв – Тх1, where
TV - condensation temperature, read from the pressure gauge on the high pressure side (remember that pressure gauges installed on the pressure manifold usually have a temperature scale),
Tx1 is the temperature of the refrigerant (liquid tube) at the outlet of the condenser.
Weak hypothermia indicates that the charge is insufficient; strong hypothermia indicates an excess of refrigerant. Refilling can be considered normal when the subcooling temperature of the liquid at the condenser outlet is maintained within 4...7 °C, with the air temperature at the evaporator inlet close to the nominal operating conditions.
a) Symptoms of low refrigerant
A lack of refrigerant manifests itself in every element of the circuit, but this deficiency is especially felt in the evaporator, condenser and liquid line of the circuit. As a result of an insufficient amount of liquid, the evaporator is poorly filled with refrigerant, which leads to a decrease in the cooling capacity of the system. Since there is not enough liquid in the evaporator, the amount of steam produced there drops significantly. Since the volumetric productivity of the compressor exceeds the amount of steam coming from the evaporator, the pressure in it drops abnormally. A drop in evaporation pressure leads to a decrease in the evaporation temperature. The evaporation temperature may drop to below zero, resulting in freezing of the inlet tube and evaporator, and the overheating of the steam will be very significant. The steam superheat temperature T2 (or simply steam superheat) is defined as the difference T2=Tx2-Tn, where
Тх2 - temperature of the refrigerant (gas tube) at the outlet of the evaporator,
Tn is the temperature of the steam in the evaporator, read from the pressure gauge on the low pressure side.
Superheat should be within 5...8 °C. With a significant lack of refrigerant, overheating can reach 12...14 °C and, accordingly, the temperature at the compressor inlet will also increase. And since the cooling of the electric motors of hermetic and semi-hermetic compressors is carried out using sucked vapors, in this case the compressor will abnormally overheat and may fail. Due to the increase in the temperature of the steam in the suction line, the temperature of the steam in the discharge line will also be increased. Since there will be a shortage of refrigerant in the circuit, there will also be insufficient refrigerant in the supercooling zone.
Thus, the main signs of a lack of refrigerant are:
- low cooling capacity;
- low evaporation pressure;
- high overheating;
- insufficient hypothermia (less than 4 °C).
It should be noted that in installations with capillary tubes as a throttling device, subcooling cannot be considered as a determining indicator for assessing the correct amount of refrigerant charge.
b) Symptoms of over-charging refrigerant
In systems with a expansion valve as a throttling device, liquid cannot enter the evaporator, so excess refrigerant is in the condenser. An abnormally high level of liquid in the condenser reduces the heat exchange surface, cooling the gas entering the condenser worsens, which leads to an increase in the temperature of saturated vapors and an increase in condensation pressure. On the other hand, the liquid at the bottom of the condenser remains in contact with the outside air much longer, and this leads to an increase in the subcooling zone. Since the condensing pressure is increased and the liquid leaving the condenser is perfectly cooled, the subcooling measured at the condenser outlet will be high.
Due to increased condensation pressure, there is a decrease in mass flow through the compressor and a drop in cooling capacity. As a result, the evaporation pressure will also increase. Due to the fact that overcharging leads to a decrease in the vapor mass flow rate, the cooling of the electric compressor motor will deteriorate. Moreover, due to the increased condensation pressure, the current of the compressor's electric motor increases.
Deterioration of cooling and an increase in current consumption leads to overheating of the electric motor and, ultimately, failure of the compressor.
Thus, the main signs of recharging with refrigerant are:
- drop in cooling capacity;
- increase in evaporation pressure;
- increase in condensation pressure;
- increased hypothermia (more than 7 ° C).
In systems with capillary tubes as a throttling device, excess refrigerant can enter the compressor, which will lead to water hammer and ultimately compressor failure.
Small (within 10%) deviations in charging the system with refrigerant from the nominal value do not lead to a significant change in the system parameters. This is confirmed by measurements of the temperature of the air leaving the indoor unit of the split system (operation in cooling mode), the operating current of the compressor and the low pressure in the refrigerant circuit with constant environmental parameters (temperatures of the outside air and air in indoors) and various circuit refills. For small deviations of the circuit filling from the nominal value, changes in the operating parameters of the split system in both modes are small.
b) Excessive length of connecting pipes
Placing split system units with height differences exceeding the value set by the manufacturer also leads to a decrease in air conditioner performance.
Increased noise when the air conditioner is running
The source of increased noise may be poorly secured parts and units of the air conditioner. To eliminate noise, it is necessary to tightly tighten all fastenings and connections of pipes and structural elements of the system. The outdoor unit must be leveled horizontally. Loose loops of connecting pipes can also be a source of noise. Such loops should not remain after installation of the climate system, but if for some reason they are left, the turns of tubes should be fastened together.
Local resistance in the system
The occurrence of local resistance in the refrigerant circulation circuit reduces its supply to the evaporator, and the suction pressure becomes lower than normal.
Resistance may be due to:
pipeline deformation;
filter clogging;
dryer blockage;
contamination of the capillary tube;
ice plug in the expansion valve.
To ensure stable operation of the system, it is necessary to eliminate the malfunction.
Deformation of the pipeline occurs when it is strongly bent, resulting in a flattened section. This malfunction is determined visually. However, if resistance occurs in the liquid pipeline, then a temperature difference is created at the point of collapse as a result of throttling of the refrigerant. If the pipeline is deformed to a significant extent, then condensation or a layer of frost will form in the area after the collapse point (Fig. 59). If the pipeline is slightly deformed, the flattened section can be straightened using a pipe expander. If this is not enough, then this section of the pipeline is cut out and replaced with a new one.
Before repairs begin, refrigerant is released from the pipeline to avoid possible injury to maintenance personnel.
The filter is designed to trap foreign particles that enter the refrigeration system and can cause equipment damage. All expansion valves are equipped with filters, and the suction pipelines are equipped with filter driers. A clogged filter reduces the flow of refrigerant and its circulation in the system may stop completely. A clogged filter also causes a decrease in pressure (and therefore temperature) in the section of the pipeline located downstream of it. If the filter is clogged, it is better to replace it. If there is no spare one, thoroughly clean the dirty filter. The filter should not be removed frequently, otherwise foreign particles and non-condensable gases may enter the system and cause various damages.
During installation, all units are equipped with dehumidifiers to eliminate the possibility of moisture and foreign particles entering the internal cavities of the unit. When the dryer is clogged, the circulation of refrigerant in the system is reduced or completely stopped.
In this case, a temperature difference is created in the line before and after the dryer (Fig. 60). The clogged desiccant is replaced. Before dismantling the dryer, release the refrigerant from the corresponding pipeline to avoid injury to operating personnel. The desiccant should not be removed from the system for a long period of time.
As a result of foreign particles entering the capillary tube, it becomes clogged, which can lead to a decrease or complete cessation of the refrigerant supply to the evaporator.
Clogging of the capillary tube manifests itself in a longer pressure equalization and is accompanied by a loss of cold.
It is recommended to replace rather than clean the capillary tube.
In this case, you should select a new capillary tube with the same length and diameter. Installing a capillary tube with other parameters will lead to unbalanced operation of the refrigeration machine and unsatisfactory cooling. The filter is replaced simultaneously with the capillary tube. The refrigerant must first be drained from the system suction line.
An ice plug forms in the refrigerant supply regulator hole of the evaporator if there is free moisture in the system. This happens when the desiccant has absorbed the maximum amount of moisture possible, and the rest of it has frozen in the expansion valve. Freezing of the expansion valve leads to changes in machine operating parameters and low suction and discharge pressures.
To make sure that moisture is the cause of the malfunction, stop the unit and apply a rag soaked in hot water to the expansion valve body. After a few minutes, a hissing sound should occur and the pressure on the suction side should increase. To eliminate the malfunction, replace the dryer. If this does not help, it may be necessary to completely bleed the refrigerant from the system, evacuate the system three times, install a larger capacity dryer, and charge the system with dry refrigerant.
The unit operates with increased load when its performance is insufficient or the cold consumption has increased. The only solution to this problem is to replace the unit with another more productive one. A significant thermal load on the evaporator occurs at high fan speeds, resulting in increased suction pressure. You can reduce the fan speed and at the same time change the difference between the temperature of the air flow passing through the evaporator and the boiling point of the refrigerant. The recommended temperature difference is usually 11°C for air conditioning and 6 - 9°C for refrigeration.
How to check the air conditioning compressor and extend its service life?
Often, the service department, when detecting darkening of the thermal insulation, air conditioner oil, or a refrigerant leak, installs a filter on the liquid line or eliminates the leak and refills the air conditioner, but in reality, radical measures are required to save the compressor, which cannot be carried out at the installation site of the air conditioner. The result of such an attitude will be the same - compressor failure. Let's consider the possibilities of repairing an air conditioner in cases where the air conditioning compressor can still be saved.
The need to repair the compressor-condensing unit of an air conditioner in a service center may arise not only in an emergency situation, for example, when a compressor fails, but also based on the results of diagnostics of the air conditioner.
Cases of such situations:
- result of express analysis of compressor oil;
- loss of tightness of the freon circuit of the air conditioner;
- moisture entering the freon circuit of the air conditioner.
In these cases, even if the air conditioning compressor is still running, its days are numbered. Urgent "reanimation" can help extend the life of the air conditioner.
Express oil analysis
It is necessary to take an oil sample from the freon circuit.
Compare its color and smell with a sample of good oil.
Using an acid test, analyze the oil for the presence of acid.
Stage I
An oil sample for analysis can be taken through the service port of the air conditioner from the walls of the pipeline when the air conditioner is stopped.
For this you will need:
- short hose with fitting and tap;
- container for collecting oil;
- a clean laboratory test tube.
Procedure:
- stop the air conditioner;
- allow the oil to drain along the walls of the pipeline for 10-15 minutes;
- connect a hose with a tap to the service port;
- place the free end of the hose in a container to collect oil;
- open the tap; the gas coming out of the hose will carry away the oil;
- collect the oil in a container;
- let the oil settle (the oil contains dissolved refrigerant - it foams);
- pour the sample into a test tube.
Stage II
Comparison of an oil sample from the freon circuit of an air conditioner with a sample of good oil by color and smell. The same amount of oil from the sample and the reference oil is placed in two identical test tubes and compared with each other.
Dark oil color and burning smell- The air conditioning compressor overheated.
The cause of overheating could be a refrigerant leak from the freon circuit of the air conditioner and operation without refueling.
An increase in pressure in the system due to contamination of the radiator of the external unit or deterioration of the fan airflow (the fan control board is not working correctly; the fan itself is broken; the winter kit for adapting the air conditioner for operation down to -25 degrees is not adjusted).
Operating the air conditioner in “warm” mode at low negative temperatures, without an adaptation kit.
As a result, the oil loses its lubricating properties, decomposes into various resinous substances and the air conditioning compressor jams.
Greenish tint of oil - the presence of copper salts in the oil. The cause is moisture in the freon circuit of the air conditioner. The acidity test of such oil will be positive.
Over time, water in the internal air conditioner system accumulates near the capillary in the external unit, freezes and clogs it. As a result, the compressor cannot pump the system, overheats and the working or starting winding burns out.
Transparent oil with a slight odor - The air conditioner does not require resuscitation.
Stage III
The acid test should either confirm the concerns and then the air conditioner needs urgent service intervention, or refute it and operate the air conditioner as normal. The taken oil must be returned to the system in the same quantity.
Procedure for returning oil:
- take suitable dishes, for example a transparent tall glass with a diameter of 3-4 cm;
- connect a valve with a hose to the service port, just like when taking an oil sample;
- lower the free end of the hose into the glass;
- pour oil into the glass so that it covers the hose fitting;
- mark the oil level on the glass;
- open the valve slightly so that the freon displaces the air from the hose;
- add the same amount of oil into the glass as was taken for testing;
- turn on the air conditioner in “cold” mode;
- close the liquid port of the air conditioner (large pipe);
- as soon as the pressure in the suction line drops below atmospheric pressure, open the valve, the oil will flow through the service port into the air conditioner;
- close the tap, when the oil level reaches the mark, immediately turn off the air conditioner;
- open the liquid port of the air conditioner.
Loss of tightness of the freon circuit air conditioner - may be caused by various reasons, but this does not necessarily lead to disastrous results.
Factors that matter:
- location of the leak;
- amount of lost refrigerant;
- the time interval between the occurrence and detection of a leak;
- mode and duration of operation of the air conditioner.
The danger of a refrigerant leak is that the air conditioning compressor, cooled by the refrigerant, overheats as a result of a decrease in the density of the latter. The compressor temperature rises. The lubrication system is disrupted, the friction of the internal parts of the compressor increases, and the current strength in the windings increases. As a result, the compressor heats up more and more and jams.
Signs of a freon leak:
- frost on the taps of the external unit;
- darkening of the compressor insulation;
- greasy oil stains;
- activation of compressor thermal protection;
- dark-colored oil with a burning smell;
- positive oil acidity test.
If a freon leak is detected in a timely manner, the refrigerant is not completely gone, the air conditioner operated without refrigerant for a short period of time, and there are no accompanying signs - repairing the air conditioner within the walls of the service center is not necessary.
The proportion of sudden leaks caused by pipeline destruction is very small. Freon leaks often occur through flared joints, and if you carefully inspect and monitor the operation of the air conditioner, leaks can be detected in a timely manner.
Please note:
The air conditioner needs no more than 10 minutes after switching on to start producing cold or warm air, depending on the selected mode. If this does not happen, you must immediately turn off the air conditioner and call a service representative. If during operation of the air conditioner the tubes on the external unit are covered with frost, a leak occurs, a service representative is needed. Following these simple rules will help you avoid high costs for air conditioner repairs.
Moisture entering the freon circuit- often occurs when the air conditioner installation rules are violated. One of the installation stages is evacuation of the fren line. This is the process of removing air and water vapor from the installed line. Blowing through the installed line with refrigerant cannot remove moisture, but only turns it into ice on the walls of the copper pipes, which then melts, turns into water and does its dirty work.
The danger of moisture getting inside the air conditioner is that it often does not manifest itself until the air conditioning compressor fails. All processes in an air conditioner operating in cold mode occur at positive temperatures, and water only manifests itself when it freezes, causing a malfunction of the capillary tube or thermostatic valve. Over time, the suction pressure of the air conditioner drops, the compressor temperature rises, and the thermal protection (tablet) is triggered. This cycle is repeated until the compressor burns out. Removing moisture from the freon circuit can also only be done at a service center.
Carrying out repairs to the air conditioner compressor and condenser unit at a service center:
- refrigerant evacuation;
- dismantling the compressor;
- releasing the compressor from oil;
- compressor flushing;
- compressor evacuation;
- filling the compressor with oil;
- compressor testing;
- flushing the input circuit of the compressor-condensing unit;
- dismantling the dryer filter;
- installation of a process filter;
- installation of the compressor in the compressor-condensing unit;
- installation of the compressor-condensing unit on the stand;
- refrigerant charging;
- washing the compressor-condensing unit on the stand;
- freon evacuation;
- replacing the dryer process filter with a working filter;
- evacuation of the compressor-condensing unit;
- refrigerant charging;
- test run of the repaired unit.
Due to the fact that contaminated oil circulates throughout the internal air conditioner system, some of the work on cleaning the freon circuit must be carried out at the installation site of the air conditioner. The purpose of these measures is to prevent dirty oil from entering the repaired unit.
Cleaning work includes:
- purging freon lines and the evaporator with dried nitrogen;
- installation of a process filter in the freon line;
- evacuation of the freon line and evaporator;
- starting the air conditioner to collect dirt on the filter;
- condensation of refrigerant into the compressor-condensing unit;
- removal of the process filter;
- evacuation of the freon line;
- starting the air conditioner and monitoring the pressure characteristics and current strength of the compressor.
All problems in the operation of split systems can be divided into two categories:
- breakdowns in the refrigeration circuit;
- malfunction of electronics and (or) electrical elements.
The most common cause of climate system failure is a freon leak. The external and internal units of the air conditioner are connected using main pipes. They are connected mechanically. This installation technique assumes a planned refrigerant leak. During annual service, specialists add a small amount of refrigerant. The norm is considered to be 150-200 g of freon per year. If the leakage exceeds this standard, then, most likely, serious errors were made during the installation work. This is the main reason indicating that installation work should not be performed by non-specialists. After all, all subsequent operational capabilities of the split system depend on this.
When performing a technical inspection of a split system, the first thing you should do is check the heat exchangers of the outdoor and indoor units. It is necessary to check whether the units are installed correctly, whether dirt gets into them, and whether ventilation is normal. Specialists use the test operating mode, which is equipped with all modern models of climate control equipment.
The specificity of the test mode of operation of the climate system is that it works for cooling, not paying attention to the temperature readings of the sensors. In this mode, the split system operates for an unlimited time - as long as the technician needs to identify the problem. After switching to normal mode, the air conditioner operates as usual.
If there is a suspicion of a freon leak from the slip system, you should immediately stop using it and begin repair work. Refrigerant leakage is determined by different methods. One of them is a noticeable decrease in suction pressure. If the suction pressure reading is below zero, air is most likely entering the system. Along with the air, moisture probably gets inside the equipment, which will cause corrosion of the insides of the air conditioner - compressor. In addition, the compressor may suffer from overheating. During normal operation, the compressor must be cooled by freon circulating in the system. If there is a lack of gas, this process does not occur fully, or does not occur at all. Of course, refrigerant should be topped up immediately.
The specialist must completely remove the freon remaining in the system and eliminate the cause of the leak. If necessary, if moisture gets inside the system, a special filter-drier, an anti-acid filter are installed and vacuum is performed.
To detect leaks, technicians use electronic devices - leak detectors of various types. Another type of device is a leak indicator. The indicators, together with freon, are charged into the air conditioner and circulate with it in a closed circuit. Ultraviolet light helps to detect a depressurized area - the indicator glows as it emerges from the damaged area to the surface. You can buy an ultraviolet lamp at any specialized store; in the modern world this is not a problem.
For a serious leak, no special equipment is needed. The oil that circulates through a closed system along with the refrigerant leaks out in places where the seal is broken.
The second category of failure of the climate system is the occurrence of a problem in the functioning of the electrical elements of the air conditioner. As a rule, the compressor fails. Replacing it entails significant financial costs and loss of time. The following may also be faulty: the starting capacitor or electric motors of the fans of the indoor or outdoor units. Malfunctions are detected by test inspection, by winding resistance or by checking the insulation on the housing. Each split system model has its own winding resistance indicators, which are specified in the instructions.
There are categories of breakdown of electrical elements, which climate control equipment independently reports using indicators on the indicator. These are typical problems that can occur with a standard non-inverter split system. There are only four of them:
1. Error in the indoor unit supply air temperature sensor;
2. Error in the temperature sensor of the heat exchanger of the indoor unit;
3. Failure of the electric motor of the indoor unit;
4. Control board failure.
Based on how the air conditioner works, the technician can also judge the nature of the malfunction. If the split system turns off immediately after turning it on, and then error information appears on the display of the indoor unit, then most likely there is a malfunction of the air flow or evaporator temperature sensors. Technically, all operating modes of the climate system are based on sensor data. They determine the order of operation of the climate system, based on the desired mode.
If the split system turns off after 15-20 seconds after starting operation, this is an indication of a breakdown of the indoor unit fan motor. If there are disturbances in its operation, the speed of revolutions decreases. The indoor unit fan motor is faulty (rotation speed is below the specified rpm).
If the split system does not turn on at all, and the LEDs do not light up at all or all blink, then most likely the control circuit board has failed. The blinking of all LEDs may also indicate a power surge in the network, which violated the software settings of the control board. This is not a difficult problem. To solve it, it is enough to reprogram the main control board. Only service technicians have the codes.
Since the operating algorithm of split systems is practically the same for all models, the cause of breakdowns can be determined by the following indicators:
air sensor when the compressor is turned on and off when the cooling and heating operating mode is established;
evaporator sensor when the indoor unit is controlled in room heating mode and emergency mode is activated when the outdoor unit heat exchanger freezes or the indoor unit heat exchanger overheats in heating mode. You can prevent freezing by setting the heat exchanger sensor to the cooling mode.
If the technician was able to timely and correctly diagnose the problem, then he will be able to eliminate the malfunction efficiently, in a short period of time. This significantly improves the comfort of life.
CHECKING THE AIR CONDITIONING COMPLESSOR
When the climate system breaks down, suspicion usually falls on a malfunction of the compressor. But upon closer inspection, it may turn out that this mechanism has nothing to do with it. Therefore, it is important that a specialist accurately diagnose the compressor.
Single-phase compressors with starting winding
To carry out diagnostic work, the air conditioner must be dismantled so as to gain access to the compressor. The contacts are located under the cover, screwed on. It can be easily detected by the wires connected to the compressor. After the cover is removed, access to the 3-pin terminals with terminals and wires extending from them opens. The wires should be disconnected and the resistance between the contact terminals should be measured with a multimeter.
The air conditioner switch is set to resistance measurement mode. The multimeter may indicate infinitely high resistance, which indicates an open. If there is built-in protection, then you should make sure that the compressor does not overheat and this is not an indicator that the protection has turned on. If external protection is installed, the compressor has failed. If the multimeter indicates a resistance approaching zero, then this indicates a short circuit that caused the compressor to malfunction.
The exact resistance indicators directly depend on the accuracy of the multimeter and the power of the compressor. The permissible rate of fluctuations in the readings is about 1-50 Ohms.
Each split system compressor is equipped with thermal protection. It can be located inside the device, or located outside, near the compressor terminals. Built-in thermal protection is also called a “pill”. External thermal protection can be diagnosed separately without much difficulty. This method cannot determine short-circuited turns. There are special instruments for measuring them, but their readings are inaccurate.
Measuring with a megger
An insulation breakdown in an air conditioner system is impossible with a conventional tester, since it can measure at a low voltage of 3-9 V. A special megger device makes it possible to take measurements at a high voltage of 200-1000 V. Before starting to work with a megger, you need to go through the windings with a multimeter. This suggests that it is impossible to measure resistance with a megger when the winding is short-circuited to the housing.
The device is equipped with switches that help you select the desired voltage, in the range of which the windings are diagnosed, as well as the time for work.
Resistance is measured between the terminals on the compressor and the copper tube coming out of it with a voltage of 250-500 V. The normal resistance value is in the range of 7-10 MOhm. If the readings are different, then the compressor must be replaced.
Before starting measuring work, you should carefully read the instructions for the air conditioner. Since the device is under high voltage, if safety precautions are violated or incorrectly used, you can get an electric shock or damage the split system.
Three-phase compressors and inverter air conditioner compressors
Since these elements do not have a starting winding, the resistance between the windings of three-phase compressors and compressors of inverter air conditioners must be the same. In general, their method of detecting breakdowns is similar to a single-phase air conditioning compressor.
Air conditioners can be classified as highly reliable products. This is due to the fact that split systems have a small number of mechanical components and assemblies, and those that exist are represented by closed devices, isolated from external influences (electric motors and compressor) and products designed for a long service life (bearings, etc.). ).
Therefore, air conditioner breakdowns are very rarely associated with its design flaws, and most often occur due to the low quality of components and materials, as well as non-compliance with the rules of their operation and maintenance.
Mechanical faults of air conditioners
Mechanical malfunctions of the air conditioner can occur:
- in the outdoor unit of the split system, where the compressor and fan for blowing the condenser are located;
- in the cooling circuit, where there are mechanical connections in the route for pumping the refrigerant;
- in indoor units where fans are located to ensure heat exchange between the evaporator and the air in the room.
Most often, such malfunctions occur in the outdoor unit, which is exposed to active atmospheric phenomena, and also possible physical impact from the ingress of foreign objects, for example, icicles, large debris such as broken branches, plastic bags, etc.
Malfunctions of the cooling circuit are most often associated with improper installation and poor quality of materials used. For the same reasons, mechanical breakdowns can occur in the internal unit of the split system.
The most dangerous types of mechanical breakdowns of the air conditioner are associated with the split system compressor, since they can provoke a whole cascade of malfunctions, the elimination of which will require significant costs. Their value can reach 50% or more of the cost of a new air conditioner.
Mechanical faults can be diagnosed by the electronic air conditioning control system. High-end split systems, a significant part of middle-class air conditioners, and even individual products in the budget segment are equipped with such self-diagnosis.
Truly good air conditioners not only detect faults, but also do not allow the unit to be used until they are corrected. In other cases, all hope rests with the owner that he will identify the malfunction in time and take measures to eliminate it. Signs of mechanical problems include:
- Extraneous noise when operating fans of outdoor and indoor units.
- Long operating time of the unit without stopping (conventional air conditioner) or deterioration of air cooling (inverter air conditioner).
- Freezing of evaporators and condenser.
- Condensate (water) leaking through the indoor unit in addition to the drainage system.
There may be other external signs of mechanical malfunctions, so if the user notices that the air conditioner has begun to work differently than usual, you should immediately contact the service department to eliminate the malfunctions, and most importantly, the reasons why they occurred:
- Natural wear and tear;
- Foreign objects entering the mechanical components of the air conditioner;
- Lack of lubricant or its poor quality;
- Loss of a critical volume of freon due to natural evaporation or depressurization of the cooling circuit;
- Clogged air filter system;
- Clogged air conditioner drainage system.
Malfunctions due to natural wear and tear usually occur among “veterans” of climate control equipment, but mainly occur due to non-compliance with maintenance regulations. Mechanical breakdowns of air conditioners, if not corrected in time, always result in failure of the compressor, which is very sensitive to operating conditions.
Each mechanical failure causes a violation of the optimal temperature regime of refrigerant circulation, as a result of which liquid freon can enter the compressor, causing its complete failure. Eliminating most mechanical faults requires little time and expense, provided you contact the service center in a timely manner, otherwise a penny breakdown can lead to thousands of dollars in expenses.
Malfunctions of the electrical equipment of the air conditioner
Modern electrical equipment of all types for any devices, mechanisms, etc. is on the path of unification. This means that the times when such equipment was repaired as its mechanical part are gone.
Therefore, circuit breakers, relays, control units, sensors and much more today “de jure” cannot be repaired. The reasons for this are the impossibility of restoring the full operational characteristics after repair, the comparability of the costs of repairs and the purchase of new equipment, etc.
Therefore, to eliminate the breakdown of air conditioners in the “electrical part”, as a rule, they resort to replacing the failed part with a new one. The main causes of malfunctions of the electrical equipment of the air conditioner are:
- Sudden voltage drops in the network;
- Low quality of electrical products and materials;
- Consequence of mechanical breakdowns of the air conditioner.
Faults associated with unstable voltage in the network, it would seem, should not occur, since all manufacturers declare the presence of appropriate automatic protection. But not everything is so simple; the quality indicators of this equipment come into play. In order not to resort to the complex terminology of semiconductor physics, we will try to explain the cause of such breakdowns “on the fingers”.
High-quality (chemically pure) semiconductors cannot withstand only a direct lightning strike, but they are expensive. “Contaminated” (with impurities) semiconductors “break through” with a voltage of 260V, but they delight the consumer with their price. The buyer himself determines what is more important to him, but he realizes this only when “thunder strikes.” Malfunctions associated with mechanical breakdowns of air conditioners are more severe than problems caused solely by electricity.
As a result of jamming of bearings, liquid freon entering the compressor, etc. The windings of the electric motors and compressor may “burn out.” Here it is possible to talk about the repair of these components (units), but the cost of the work, most often, turns out to be such that replacing them with new products will be more than justified.
Be sure to watch this video about the most common causes of air conditioner breakdowns.
The intervention of a specialist is not always necessary to eliminate breakdowns of climate control equipment. There is a lot you can do with your own hands. You just need to know the typical ones and their elimination. We will talk about this in our article today.
Automatic diagnostic system
The first thing you need to do is make sure that the air conditioner is broken. Fortunately for the user, modern climate control equipment has a warning function about possible problems. Typically, various colored indicators flash or corresponding messages appear on the display. Deciphering diagnostic information is not difficult. Manufacturers indicate fault codes for air conditioners in the instructions.
Of course, not all codes are decipherable for the user. The bulk of them are available only to specialists from technical centers for the repair and maintenance of climate control equipment. But the user can obtain most of the data. Often, in the event of a malfunction, a lamp or diode will blink a certain number of times, based on what error the system has detected.
Standard fault codes
If the diode blinks once, then the thermistor installed on the internal unit of the split system is not working correctly or is not functioning at all. Two signals will indicate that there are errors in the operation of the thermistor on the outdoor unit. Three flashes - the device is operating in heating and cooling mode simultaneously. If the lamp blinks four times, then the overload protection is disabled. Five are errors in the operation of the information exchange system between air conditioner units. This may indicate problems with the cable between the units. Six flashes - the level of energy consumption has significantly exceeded the norm. It is recommended to test power transistors and other elements. Seven blinks will indicate that the operating voltage of the external unit has increased significantly. If the user sees that the light comes on 8 times, then there is a problem with the electric fan motor.
Nine signals - the directional valve is broken. And finally, 10 blinks indicate a failed thermistor. In this case, the compressor temperature is no longer monitored. Air conditioner malfunctions and their elimination are typical for most brands and models from different manufacturers. As for error codes, each model has its own. You can find it in the instructions for use and program the operation of the control board yourself.
How to diagnose an air conditioner
Any air conditioner repair begins with an inspection. This is also done before implementing preventive measures. Diagnostics should include inspecting the device for various mechanical damage. It is also necessary to check the reliability of the blocks and electrical connection clamps. Then they check the condition of the filters and the operation of the device in different modes.
After this, you can test the operation of the display system. It would be useful to check how the blinds work and what the temperature is on the evaporator. Measure the pressure level in the suction/discharge system and check the tightness of all connections.
The device does not turn on
These are the most basic malfunctions of air conditioners, and every owner has encountered them at least once. Regardless of the brand, model, country of origin, the reasons will be the same. This problem lies in the electrical part and lies in the fact that the device is simply not connected to the power supply, the control board is faulty, or there is no connection between the indoor and outdoor units. Another common reason is failure of the remote control or the receiving module of the device. There is one more problem. Due to certain circumstances, the device could go into protection mode and display an error when turned on. Finally, the device does not turn on due to the banal wear of some parts. In some cases, the split system does not work or does not carry out the owner’s commands correctly due to incorrect switching in the signal and power wires connecting the units.
If such problems arise, you should reconnect the wires according to the diagram. It is better to do this as quickly as possible, otherwise more serious malfunctions of the air conditioners are possible, and their elimination will take a lot of time. All this can cost a significant amount of money.
The split system turns off after 10 minutes of operation
This may indicate the compressor is overheating. Such troubles arise due to faults in the control board or due to a faulty protective relay. The first step is to check whether any malfunctions are observed. This unit may overheat if the radiator on the external unit is clogged with dirt. This can greatly interfere with heat removal; the compressor operates at a higher load, resulting in overheating. In this case, preventative cleaning will help. If the system has recently been charged, then there may be imbalances in the condenser and evaporator circuits. For this reason, the compressor will experience overload. It is necessary to make sure that there is normal pressure in the lines.
If it is higher, excess refrigerant is released. Do not rule out a malfunction of the fan on the external unit. It may not rotate at all or operate at significantly lower speeds. The temperature of the air conditioner also increases due to blockages in the capillary tubes during installation. These problems can be solved by replacing one of the tubes. The filter drier may be clogged.
Condensate leak from the indoor unit
In the summer, air conditioner users may encounter overflowing containers that collect condensation. To prevent water from running out of the container, it is necessary to regularly drain the liquid from it. If the reason is freezing of the heat exchanger, it is recommended to insulate it with heat-insulating materials. When leaks are observed at the joints, it is necessary to tighten the nuts. The joints should be treated with sealants. These air conditioner malfunctions and their elimination are extremely simple. It happens that the drainage tube becomes clogged. To do this, the plastic part is cleaned, and then there will be no more dripping from the indoor unit.
Ineffective work
This is one of the popular breakdowns. It happens especially often in the summer. During operation, the unit consumes huge amounts of energy, but cannot provide the required temperature conditions. This may be due to clogged air filters.
Also, inefficiency occurs due to dust on the impeller, which is located in the indoor unit. This can also be caused by contamination of the heat exchanger on the outdoor unit and refrigerant leakage.
Smells
If the air from the air conditioner begins to smell unpleasant, then there are some reasons for this. If there is a burning smell, this indicates a fire in the wiring. In such a situation, only repair of air conditioners in a specialized service can help. If the smell is typical of plastic, this indicates that the manufacturer has saved on materials. If there is a smell of dampness and mold, a colony of bacteria has formed inside the system. You can get rid of them using any antifungal drug.
Summary
This way you can fix simple air conditioner breakdowns with your own hands. Serious malfunctions often occur very rarely. If you constantly carry out preventative maintenance on the system, breakdowns can be completely eliminated.
What problems can occur with air conditioners? Let's take a quick look at the most common ones. It often happens that the instability of our electrical networks simply disables the device’s control board. Often these are relays that control the operation of a fan, motor, and so on. It’s not very often that the remote control fails, but such malfunctions are predominantly mechanical.
Air conditioner motor failure
The most common cause of fan and motor failure is bearing wear. To fix this problem, the bearings need to be replaced. Another interesting feature regarding fan failure is related to its operation in winter, in particular, at zero degrees, when water melts or freezes. Thus, water that drips from the roofs onto the outdoor unit of the device freezes on it and causes malfunction of the blades; they partially or completely fail, which is why the relay, which is responsible for activating/deactivating the device, simply burns out.
Freon
Insufficient cooling can occur when air leaks, without which the air conditioner, unfortunately, cannot operate. The solution to this situation is to add freon, but first you must identify the reason why the leak is occurring; without this, the device will continue to work “idle”. There may be several reasons for this - the substance poisons the spool, it escapes along the rubber seals located on the air conditioner taps; in addition, it can break through the freon line, and in many places. One way or another, the leak must be detected, and only after that the device must be refilled with freon. It is impossible to refill the air conditioner with freon yourself without special skills and equipment, so in this case you should contact specialists http://e-klima.ru/pages/repair
Air conditioning compressor problem
Another common one is the failure of its compressor. In most cases, such a breakdown is a sure sign of impending expensive repairs, perhaps the most expensive of all known breakdowns. Note that the cost of repairs may be close to the cost of the air conditioner itself, although this applies more to low-power equipment. Then you, as the owner of the air conditioner, must decide for yourself whether it is advisable to repair it at all. So the main problem with this kind of breakdown lies, first of all, in the correctness of the “diagnosis”, and you can be sure of it only when real specialists were involved in the diagnosis.