What is the reason why the air conditioner does not work properly? Let’s conduct a comprehensive analysis
Summer is the season when air conditioners are used most frequently, especially when sleeping at night. It is no exaggeration to say that many people will not be able to survive without air conditioners. However, the most annoying thing at this time is of course the inexplicable strike of the air conditioner and its malfunction. What caused these situations? Let’s take a look at some common faults in air conditioners.
1 Let’s first take a look at a summary table (take R22 as an example)
fault
Observation area air conditioner is normal, refrigerant is insufficient, filter is blocked
Low pressure (ambient 30℃)0.45~5.0 Lower than normal pressure Lower than normal pressure
High pressure (ambient 30℃)1.9~2.0 Lower than normal pressure slightly lower than normal pressure
Balance pressure at shutdown Saturated pressure at ambient temperature Saturated pressure at ambient temperature; severely lower than saturated pressure Saturated pressure at ambient temperature
The sound of the compressor is normal and slightly lighter
The temperature of the compressor suction pipe is cold, and dew is condensed. In humid weather, a lot of dew is condensed, little dew is condensed, or no dew is condensed, warm
Compressor exhaust pipe temperature is hot, hot, 55℃ plus ambient temperature Hot, warm, warm, below ambient temperature plus 55℃
The compressor shell temperature rises at around 90℃, and the temperature rises above 90℃, and the temperature rises above 90℃.
Condenser is hot, ambient temperature is added to 15℃(45℃~55℃) heat, warm temperature is added to 15℃ below ambient temperature
The evaporator is cold, all dew condensation occurs, local frost occurs when the ambient temperature is reduced by 15℃, and even local frost occurs on the ice layer
Filter temperature, ambient temperature plus 2℃~5℃, dew condensation will occur at the outlet, and even frost will occur. Cold, dew condensation, frost will occur
Capillary tubes are cold at room temperature, and even dew condensation, frost condensation, frost condensation
fault
All refrigerant leaks in the observation area, and the condensation conditions are poor. The evaporator is blocked externally
Low pressure (ambient 30 ° C) Basically no pressure Above normal pressure Below normal pressure
High pressure (ambient 30 ° C) Basically no pressure higher than normal Pressure Normal
Equilibrium pressure at shutdown is basically non-pressureSaturation pressure at ambient temperature Saturation pressure at ambient temperature
The compressor is soft and loud
The temperature of the compressor suction pipe is warm and cold, with excessive dew condensation
The temperature of the compressor exhaust pipe is warm and hot. It exceeds the ambient temperature and adds 55℃ heat, and is slightly below 55℃ and adds ambient temperature.
The compressor shell temperature is hot and hot, far above 90℃, the temperature rises, and below 90℃, causing excessive dew condensation
The condenser temperature is overheated, 15℃ is added to the ambient temperature, and 15℃ is added to the ambient temperature
The evaporator is warm and cold without condensation. It is 15 ° C higher than the ambient temperature. Frost appears after too much condensation, and gradually expands to ice.
Filter warm
capillary temperature
fault
There is too much refrigerant in the observation area, and there is a high and low pressure leak from the air compressor in the system.
Low pressure (ambient 30 ° C) Above normal Pressure Above normal Pressure
High pressure (ambient 30 ° C) Above normal pressure Above normal pressure Below normal pressure
Equilibrium pressure at shutdown Saturation pressure at ambient temperature Saturation pressure at ambient temperature Saturation pressure at ambient temperature
The compressor is loud and soft
The temperature of the suction pipe of the compressor is cold, the condensation of dew is too cold, warm, and the condensation of dew is less warm, or even hot
Compressor exhaust pipe temperature is hot, hot, above ambient temperature plus 55℃ heat, hot, above ambient temperature plus 55℃ heat
The temperature of the compressor shell is low, the condensation is too high, the temperature rises, the temperature exceeds 90℃, the heat is hot, far exceeds 90℃
Condenser heat, above ambient temperature plus 15 ° C heat, above ambient temperature plus 15 ° C temperature, hot
The evaporator is cold, the dew condensation is too cold, but the dew condensation is less, which is higher than the ambient temperature minus 15 ° C temperature and heat
Filter temperature, hot temperature, hot temperature
Capillary room temperature temperature
2 Insufficient cooling capacity under refrigeration conditions
1. There is cold wind but not cold inside
Ø. Overload with cold load. For example, the room is too big, there are too many people in the room, and there is a heat source to dissipate heat.
Ø. Installation position. Such as sun exposure, poor ventilation of outdoor units, etc. The indoor unit is poorly positioned and the air-conditioning cycle is poor.
Ø. The indoor air filter has not been cleaned for a long time, dust blocks the mesh, poor ventilation, and poor cooling air.
Ø. The refrigeration system is blocked or refrigerant leaks, causing poor refrigeration effect of the evaporator.
2. The compressor can run, but the supply air is not cold enough.
Ø. The outdoor temperature is too high. The air conditioner has limited capacity and cannot be cooled to the desired comfortable temperature.
Ø. Serious ash deposition in the condenser, poor ventilation, and poor heat dissipation effect, resulting in a decrease in the cooling capacity of the air conditioner.
Ø. Installation position: outdoor units are exposed to the sun; indoor units are positioned too high, too low, and at an angle, resulting in poor air-conditioning circulation.
Ø. After the refrigeration cycle system is blocked and the capillary tube or dry filter is blocked, the liquid refrigerant flowing into the evaporator is reduced and the refrigeration capacity is reduced.
Ø. The electromagnetic four-way reversing valve, reversing valve solenoid, and hot and cold reversing switch are faulty, resulting in poor cooling effect or no cooling.
3. The compressor stops as soon as it starts
Ø. The outdoor temperature is high, the condensation pressure rises, the compressor is overloaded, and the protector automatically cuts off the power supply and stops. If the air conditioner is allowed to operate normally, the switch can be placed in medium or low cold gear to reduce the cooling load and allow the air conditioner to continue to operate.
Ø. Installation position, the outdoor unit has strong sun exposure and blocked ventilation, resulting in poor condensation effect and shutdown.
Ø. Abnormal high voltage or low voltage, the compressor cannot start, the current is too large, and the overload protector acts and stops.
Ø. The capacity is not enough, the line pressure drop is large, and the overload protection period is activated and the machine stops.
Ø. Poor contact or damage to the capacitor makes the compressor unable to operate normally.
3 No refrigeration at all under refrigeration conditions
1. Fan motor does not rotate
Ø. Poor plug contact or broken power cord is the main fault. The power cord must be replaced and the plug must be checked.
Ø. Poor electrical contact or faulty temperature controller, repair or replace components after finding out the cause.
Ø. The capacitor is in poor contact or damaged and needs to be repaired.
Ø. Parts are broken and fan motor is out of power. Repair it after finding out the cause.
Ø. Fan motor, check whether the fan leaves are stuck and whether the motor windings are damaged. If they are damaged, they should be replaced.
2. The fan motor can operate, but the compressor cannot operate
Ø. Low voltage and high current, and the compressor overload protector acts.
Ø. The power supply capacity is too small, the voltage drop is large, and the machine is shut down after being protected.
Ø. If the electrical line is disconnected, it will be recovered after investigation.
Ø. The compressor itself fails, replace it with a new compressor.
3. The compressor can operate, but there is no cold air
Ø. Leakage in the refrigeration cycle system.
Ø. The refrigeration cycle system is blocked, the capillary tubes or dry filters are all blocked, and the evaporator cannot get refrigerant and does not cool it.
Ø. The compressor itself is damaged.
4 Insufficient heat under heating conditions
1. There is hot wind, but the room is not warm
Ø. The room is large, and the heat load of the air conditioner is insufficient, which cannot effectively increase the room temperature; the outdoor temperature is too low, and the heating capacity of the air conditioner is not enough.
Ø. The installation position is inappropriate, the airflow circulation is not good, and the heating cannot be blown to places where people are.
Ø. The air filter is blocked, the air circulation is not good, and the heater effect is not fully exerted.
2. The compressor is running, but the supply air is not hot enough
Ø. Poor installation position.
Ø. The outdoor temperature is low, the temperature difference between indoor and outdoor is large, and the room cannot heat up.
Ø. The refrigeration cycle system is blocked, and the heat pump air conditioner has poor heating effect.
Ø. Refrigeration cycle agent leaks, and the refrigeration cycle system cannot perform its normal heating function.
3. Stop the compressor immediately after starting
Ø. The installation position is not good, the air flow is blocked, the condenser (indoor side heat exchanger) is not effective, and the exhaust pressure is too high and the machine stops automatically.
Ø. If the voltage is too low or too high, the compressor protector will act.
Ø. The power supply capacity is not enough, the pressure drop is large during startup, and the compressor protector acts.
Ø. The capacitor is loose or damaged, and the motor will automatically stop due to high current after starting.
5 No heating at all under heating conditions
1. Fan motor does not rotate
Ø. The power cord is faulty and the fan motor has no power. The cause should be found out.
Ø. The automatic thermostat and switch caused a circuit failure due to poor contact, and the fan motor had no power.
Ø. The capacitor is damaged or the connector is loose, and the motor cannot operate.
Ø. The electrical circuit is faulty and the fan motor cannot operate.
Ø. Fan motor windings are open or shorted.
2. The fan motor can rotate, but the compressor does not operate
Ø. The voltage is too low or too high, caused by the compressor protector.
Ø. Switch, automatic thermostat, improper position, or poor contact, blocked circuit, compressor has no electricity and does not rotate.
Ø. There is a problem with the electrical circuit and the compressor cannot operate.
Ø. The compressor itself fails.
3. The compressor can operate, but there is no hot air
Ø. The refrigeration cycle system leaks and there is no refrigeration system in the system.
Ø. The refrigeration cycle system is blocked.
Ø. The compressor itself is damaged.