First, the air conditioning circuit fault maintenance ideas
From the ends of the indoor to the outdoor to the middle, it is easy to be easy first and then difficult.
In order to make circuit fault repair specific and simple, it is necessary to distinguish between indoor and outdoor circuits, main circuits and control circuit faults during maintenance.
Second, the control and main circuit failure
1. For the compressor frequent start and stop failure, the fault part can be judged by measuring the load voltage of the air conditioner and the compressor operating current.
If the compressor operating current is too large, the fault is in the main circuit; if the compressor operating current is normal, the fault is in the control circuit.
2. For the fan running compressor does not start the fault, the fault part can be determined by observing whether the outdoor AC contactor is suctioned.
If the contactor is closed and the compressor is not working, the fault is in the main circuit; if the contactor is not absorbed, the fault is in the control circuit. For inverter air conditioners, the press does not start and can be eliminated by detecting the power module.
3. Measure whether the indoor and outdoor protection elements are normal to determine the fault area.
If the measurement protection element is normal, the fault is in the control circuit; if the measurement protection element is damaged, the fault is in the main circuit.
4. For the compressor not to operate and fail, it is also possible to observe whether the compressor can be cooled normally by forcibly pressing the contactor.
If the compressor can run and refrigerate after pressing the contactor, the fault is in the control circuit; if the contactor compressor is overcurrent or does not start, the fault is in the main circuit. (Inverter compressors can not use this method)
5. For the compressor frequent start failure, such as touching the compressor shell temperature is too high, most of the main circuit or the compressor itself is faulty.
6. For inverter air conditioners, they can be judged by the fault indicator of the air conditioner, such as power modules, communication failures, etc.
Third, indoor and outdoor circuit failure
1. Air conditioners with input and output signal lines can be judged using the short-connect method.
If the air conditioner can return to normal after using the above method, the fault is in the outdoor unit; if the fault is not eliminated, the fault is in the indoor unit.
2. Measure whether there is AC or DC voltage on the terminal of the outdoor unit to determine the fault part.
If there is an AC or DC voltage on the measuring outdoor terminal block, the fault is in the outdoor unit; if there is no AC or DC voltage measured, the fault is in the indoor circuit.
3. The cabinet air conditioner with large power can be judged by observing whether the outdoor contactor is absorbed or not.
If the contactor is suctioned, the fault is in the outdoor unit; if there is no suction, the fault is in the indoor unit.
4. For the air conditioner with fault display, the fault part can be distinguished by observing the indoor and outdoor fault codes.
5. For the air conditioner circuit using serial communication, the waveform of the signal line can be measured by an oscilloscope to determine the fault part.
6. For heat pump type air conditioners that do not defrost or defrost frequently, they are mostly outdoor main control circuit board failures.
7. Conditional can also distinguish outdoor unit failures by replacing the circuit board.
Fourth, the air conditioning failure routine maintenance methods
1. Plug in the power plug, the indoor unit power indicator is on, if there is no power indication, it means that your home power supply is faulty or the indicator light is damaged.
2, there is a power indicator, use the remote control to press the operation key, the signal can not be transmitted. First, check whether the battery in the remote control is charged, and then check whether the positive and negative plate contacts of the battery are oxidized and corroded.
If the above is normal, check whether the internal circuit board of the remote control is damaged, you can put the remote control * near a modulation radio, press the remote control button for interference test, listen to whether the radio emits a "beep" sound, and the sound indicates that the remote control is faultless.
3, when the remote control determines that there is no fault, the signal is still not transmitted, can be verified by the indoor unit forced to run the switch, forced to run, indoor through flow fan and outdoor compressor if the operation is normal, the cooling effect is good, it proves that the indoor unit infrared receiving part of the air conditioner is faulty.
4, when you use the remote control with a new battery less than a month to use it does not show, you can open the back cover of the remote control, with 95% alcohol to clean the circuit board and button contact surface conductive film, after drying, you can eliminate the leakage fault, the remote control LIQUID crystal display is missing words can also be used this method.
5, the temperature sensor in the inverter air conditioner plays a very important role, the indoor unit has an air temperature sensor and an evaporator temperature sensor;
Outdoor unit has air temperature sensor, high voltage pipeline sensor and low pressure pipeline sensor, some sensors in the long-term use of resistance changes, so that the control characteristics change, (such as indoor air temperature sensor resistance becomes larger, will cause the inverter output frequency is low), in order to ensure control accuracy, and its same working characteristics, after determining the sensor failure, should be replaced with the original model of the product.
6. When the air conditioner fails, if the entire control system is faulty, the switch on the indoor unit controller can be placed on the "trial run" gear, at which time the microprocessor will send a signal with a frequency of 50Hz to the frequency converter.
If the air conditioner can run at this time and keep the frequency unchanged, it is generally believed that there is no major problem with the entire control system, and it can be focused on checking whether the sensors are intact. If the air conditioner does not operate normally, it means that the control system is faulty.