At the same time, students can stimulate the interest of the root cause of the fault by observing the fault phenomenon of the faulty machine, from passive learning to active seeking. Observe when observing: observing the phenomenon (including the end of the capillary, evaporator, condenser, piping, etc.). For example, observe the frost at the outlet end of the capillary. At the beginning of the normal cooling operation, a thin layer of frost is formed on the capillary tube, and then gradually melts, but it is necessary to distinguish the phenomenon that the refrigerant is missing and the micro-blocking frost cannot melt; when the heat pump type air conditioner is in the heating cycle in winter, the outdoor condenser becomes For the evaporator, it is a low-pressure, low-temperature component. If you see the outdoor capillary outlet to the evaporator (which becomes the evaporator when heating), there is a frost layer on the tube and other parts are dry, indicating that the capillary is slightly blocked or the refrigerant is insufficient. Take out the air filter to see if it is clean. If the dust is too thick, it may hinder the air flow: see if the piping components of the refrigeration system are intact. If there are traces of oil leakage, it means there is a refrigerant leak point, etc. These fault phenomena can be observed directly. When the three terminals of the compressor are tested by the meter test, even if the measured resistance value is normal, the three terminal cards and the three terminals cannot be inserted incorrectly during the plugging. For example, if the single-phase compressor is inserted incorrectly, not only The compressor can not be started, and the compressor will be burnt. If the three-phase compressor is inserted incorrectly, the compressor motor will be reversed, and the internal refrigeration oil will not rise along the oil line, which will cause the compressor to block or burn the motor. It can be seen that in the maintenance process, all kinds of operations should be very cautious, select reasonable processing methods, and display their own skills according to the actual situation. This is inseparable from the usual practice, let the students do it themselves, but must make the students master the maintenance methods and precautions during maintenance. Teachers should be in place, not offside; be guided, don't do it for you. Let the students repair the faulty machine according to the correct ideas summarized above. Whenever a faulty machine is repaired in the hands of a student, they really realize the joy of success and the joy of learning. Analysis and analysis refer to the analysis of phenomena through listening, watching, touching, and checking, to falsely preserve the truth, and to obtain correct judgment conclusions. Therefore, students are given a certain amount of time and space to guide students to observe, combine the theoretical knowledge analysis, synthesis, induction, judgment and other methods to discuss, think, and explore, and give full play to students' subjective initiative. It is allowed to check the air conditioner maintenance information, and it can also be discussed with classmates and teachers. Through the students' own efforts, find out the cause of the failure, and figure out the ideas for troubleshooting, and then summarize their own opinions (the views may be immature or incorrect, but they have been thinking). This process cannot be done on its own, otherwise students cannot learn to think and cannot develop the ability of students to learn independently. Moreover, the four systems of the air conditioner are related to each other and affect each other. It is not easy to assert in the reasoning analysis. Generally, after the teacher's guidance and finally repairing a fault machine, I ask the students to reflect in time. Find out the regularity of maintenance, refine the thinking method, write maintenance tips, repair experimental failure reports or write a small paper. This not only stimulates students' interest in the exploration of maintenance technology, but also deepens the students' mastery and deepening of knowledge, and contributes to the improvement of maintenance skills. In order to get a good maintenance course, teachers should thoroughly read the teaching materials, find the key points and difficulties of knowledge; participate in maintenance practice and sum up experience; contact the principles learned in teaching to carefully set up inspiring faults, so that students can be guided by teachers. Positive thinking, find ways to solve problems, and form a certain ability to maintain thinking. In order to enrich the content of the classroom teaching, I will classify and replace the components that are usually repaired and replaced with the labeling, indicating the fault phenomenon and the testing process. Combine the content of the study and pass on my maintenance experience to the students, so that when the students are listening to the class, they have the feeling of being in the same place, which is conducive to the mastery of knowledge and the improvement of skills. In order to cooperate with classroom teaching, students are required to use the spare time to organize the maintenance of air conditioners and air conditioner installations. On the one hand, it improves students' ability to master new knowledge and new technologies, broadens their knowledge, and on the other hand improves students' self-consciousness and lays a foundation for classroom teaching. At the same time, it solves the problem of restricting students' understanding of various models, multiple circuits and various phenomena due to the limitations of school conditions. In short, the essence of classroom teaching is to let students learn knowledge and learn under the guidance of teachers. They not only focus on the current knowledge and skills training, but also focus on the development of capabilities and future development, giving full play to the subjective initiative of students. If he wants to learn for him, this is the essence of classroom teaching. weihaimaideqi , https://www.weihaimaideqi.com