A certain degree of refrigerant leakage occurred in the pipelines of the air conditioning system, or the indoor unit fan motor was abnormal, or the air conditioner was defrosting.
When the refrigerant leaks to a certain extent in the pipelines of the air conditioning system, the suction temperature of the air conditioning compressor will increase, the exhaust temperature will increase, and the refrigerant flow in the evaporator will be insufficient, causing the indoor fan to After the motor is turned on, the temperature of the heat exchanger coil drops rapidly. When the coil temperature drops to the anti-cold wind protection temperature value set by the air conditioning program, the indoor fan stops running and becomes hot and cold for a while.
When the air conditioner is heating and heating, it will run the defrost function from time to time. This is because in winter, when air conditioning is used for heating, frost may form outdoors and then defrost. The lower the outdoor temperature, the more frequent the air conditioner will frost and defrost (that is, some users reported that it sometimes blows cold air or does not heat); the greater the outdoor relative humidity, the thicker the air conditioner will frost and the more defrost water will form.
Extended information:
Conditions for the air conditioner to exit the defrost state:
1. The defrost time is greater than 9 minutes.
2. After defrosting for 4 minutes, the temperature of the inner coil is greater than 0 degrees, and the coil temperature rises by more than two degrees within 10 seconds.
3. After 5 minutes of defrosting, the internal coil temperature is greater than or equal to 5 degrees.
4. The current transformer detects that the current is too large (relative to the cabinet).
If any of the above conditions is met, it will automatically exit the defrost state
The principle of air conditioner defrost is that when the defrost sensor senses that the outside temperature is lower than a certain temperature, it will transmit a signal. to the control board. At this time, the control board transmits the defrost signal to the relevant components for defrosting. At this time, the defrost controller controls the reversal of the electromagnetic steering valve to reversely circulate the heat of the air conditioner to the outdoor unit and release the heat to the evaporator. Defrost the surface.
Baidu Encyclopedia—Air conditioner defrost