Three steps of electrical troubleshooting
1. Observe and investigate the fault phenomenon
There are many kinds of electrical fault phenomena. For example, the same type of fault may have different fault phenomena, and different types of fault may have the same fault phenomenon. The identity and diversity of this fault phenomenon bring complexity to fault finding. However, the fault phenomenon is the basic basis for the maintenance of electrical faults and the starting point of electrical fault maintenance. Therefore, it is necessary to carefully observe and analyze the fault phenomenon, find out the main and typical aspects of the fault phenomenon, and find out the time, place, environment, etc;
2. Preliminarily determine the fault scope and reduce the fault location
Analyzing the cause of fault according to the fault phenomenon is the key of electrical fault maintenance. The analysis is based on the basic theory of electrical and electronics, a full understanding of the structure, principle and performance of electrical equipment, and the combination of the basic theory of electrical and electronics and fault practice. There may be many reasons for an electrical fault. It is important to find the main reason among the many reasons;
3. Determine the location of the fault
It is determined that the fault location is the daily acceptance and result of thrifty repair of electrical fault. Determining the fault location can be understood as determining the fault point of the equipment, such as short-circuit point, damaged components, etc. it can also be understood as determining the variation of some operating parameters, such as voltage fluctuation, three-phase unevenness, etc. The fault location is determined on the basis of careful investigation and detailed analysis of the fault phenomenon.
Eight skills of electrical troubleshooting
1. Be familiar with the circuit principle and determine the maintenance scheme
When the electrical system of an equipment fails, do not rush to disassemble it. First, understand the phenomenon, process, scope and cause of the failure of the power equipment. Be familiar with the basic working principle of the equipment and electrical system, and analyze each specific circuit. Make clear the relationship between all levels in the circuit and the context of the signal in the circuit. Combined with practical experience and careful thinking, determine a scientific maintenance scheme.
For example, to find the cable fault point during the commissioning of the cable fault locator for a unit, it is necessary to fully communicate with the technicians managing the cable, obtain relevant information and formulate the maintenance plan. First judge the type of cable fault according to the measured insulation resistance, and then judge what method to test. Only in this way can we achieve the effect of "twice the result with half the effort", otherwise it is often "twice the result with half the effort".
2. First machine loss, second circuit
Power equipment is based on the principle of electrical machinery, especially the advanced equipment of mechatronics. Machinery and electronics cooperate organically in function and are two parts of a whole. Often mechanical parts fail, affecting the electrical system, and the functions of many electrical parts do not work. Therefore, do not be confused by the surface phenomenon. The failure of the electrical system is not all electrical problems, but may be caused by the failure of mechanical parts. Therefore, it will often get twice the result with half the effort to repair the faults caused by the mechanical system first and then eliminate the faults of the electrical part.
3. First simple, then complex
Troubleshooting should first be handled with simple and easy methods, and then with complex and accurate methods. When troubleshooting, first eliminate intuitive, obvious, simple and common faults. After troubleshooting, difficult and untreated faults are eliminated.
4. First check and repair diseases, and then attack difficult and miscellaneous diseases
Power equipment is often prone to the same type of fault, which is a "common fault". Because common problems are common and accumulated experience is rich, they can be eliminated quickly. In this way, we can concentrate our energy and time to eliminate difficult and strange diseases that are rare, difficult and strange, simplify the steps, narrow the scope and improve the maintenance speed.
5. External debugging before internal processing
External refers to various switches, buttons, sockets and indicator lights exposed outside the electrical equipment to complete the outside of the seal. Internal refers to the printed circuit board, components and various connecting wires inside the shell or seal of electrical equipment. External debugging first and then internal processing, that is, without dismantling the electrical equipment, use the switches, travel buttons, buttons and other debugging and inspection on the electrical equipment panel to narrow the fault scope. First, disassemble the internal parts and then eliminate the unnecessary faults.
6. Power on test after power off measurement
First, check and repair the power equipment when it is not powered on: make sure it can be powered on, and then check and confirm the maintenance of the power equipment when it is powered on. When overhauling many failed electrical equipment, it cannot be powered on immediately, otherwise it will artificially expand the fault range and burn more components, resulting in undue losses. Therefore, before the fault machine is powered on, measure the resistance first and take necessary measures before it can be powered on for maintenance.
7. Public circuit before special circuit
If the common circuit of any electrical system fails, its energy and information cannot be transmitted and distributed to each specific special circuit, the function of the special circuit will be affected and the performance will not work. If the power supply of an electrical equipment fails, the whole system cannot operate normally, and the energy and information transmitted to various special circuits cannot be realized. Therefore, following the order of public circuit first and then special circuit, the faults of electrical equipment can be eliminated quickly and accurately.
8. Sum up experience and improve efficiency
There are all kinds of faults in power equipment. After the maintenance of any faulty power equipment, you should record the fault phenomenon, cause, maintenance process, skills and experience in a special notebook, learn and master the electromechanical theoretical knowledge of various new power equipment, be familiar with its working principle, accumulate maintenance experience, and raise your own experience to theory. Under the guidance of theory, specific analysis of specific faults can eliminate faults accurately and quickly. Only in this way can we train ourselves to be an expert in troubleshooting power failures.
Newton once said, "if I see farther than others, it is because I stand on the shoulders of giants." Mastering the knowledge and experience of predecessors can help us acquire knowledge more quickly and summarize our own experience in our future work.