What is the reason why the external air conditioner does not work? Check these points
Before introducing the troubleshooting process, let’s briefly talk about the air conditioning working process. Turn on the power and turn on the machine. The indoor unit fan runs to collect indoor ambient temperature data, and then combines the parameters set on the remote control to control the operation of the outdoor compressor and fan.
Then let’s understand the wiring method of the outdoor unit’s wiring terminals. The indoor and outdoor connections of fixed frequency air conditioners generally have five wires: 1 the compressor power supply end, 2 the common zero line is short, 3 the four-way valve coil power supply end, 4 the fan power supply end, and 5 the ground wire terminal (some are on the terminal strip, some are on the chassis)
Brands have different positions, but the basic principles are the same. When the outdoor unit does not operate when the refrigeration is turned on, first observe the outdoor unit to see whether the whole unit is not working or whether the compressor and fan are alone not working. If the whole machine does not rotate, the first consideration is whether there is a problem with the mode and temperature settings. Then measure if the voltage between the zero line end of the terminal block to both ends of the press and the fan is 220v, which means that it is due to an external machine. Open the casing and follow the line to find the corresponding original. Check whether the line is burned out and open, whether the capacitance of the compressor and fan is normal, and whether the winding organization of the compressor fan is normal.
When the capacitors of the press and fan are damaged, they will deform to varying degrees (except for capacity reduction)
If there is no voltage output from the two terminals, it is a problem connecting the machine cord to the control board. You can check whether the connection line has aging, wiring interface and other problems. Whether there is a false connection phenomenon on the main board, whether there is a 12V control voltage at the control end of the fan and press control relay. If there is a 12V relay problem, replace it. If there is no 12V voltage, it means that it is a control command problem, and the control chip part does not need to be checked again, which is of little significance to maintenance. You can directly check the two temperature sensors of the indoor unit. The two sensors of room temperature and tube temperature are actually two thermistors that change with temperature, so it is best to use alternative methods.
When the outdoor press or fan does not operate alone, the process and treatment method are the same as above. But one thing can be sure, that is, the motherboard control is normal. In addition, there are also some models with the “triple power-on protection” function, which means that after the press is powered on three consecutive times and cannot start normally, the whole machine will shut down. Therefore, when the air conditioner fails to cool the external unit, the inspection should start with the external unit, and the failure rate of the outdoor unit itself is higher than that of the indoor unit.