Analysis and diagnosis of faulty faults in induction melting furnaces 1
The process of inspection, analysis and diagnosis of the induction melting furnace fault is also the troubleshooting process. Once the cause is identified, the fault is equal to the exclusion. Therefore, the method of fault analysis and diagnosis becomes very important. The inspection and analysis of the fault is the first stage of troubleshooting, and it is a very critical stage. The following work should be done mainly.
1) Familiar with circuit principle, determine maintenance plan
When the induction melting furnace fails, do not rush to disassemble. First, you must understand the phenomenon, passage, scope and cause of the induction melting furnace. Familiar with the composition and basic working principle of the induction melting furnace, analyze each specific circuit, clarify the interconnection between the various levels in the circuit and the ins and outs of the signal in the circuit, combined with practical experience, after careful thinking, determine a scientific maintenance program. And to the field operators to understand the situation before and after the fault, such as overload before the fault occurs, frequent start and stop; whether there is abnormal sound and vibration when the fault occurs, there is no smoke, fire and so on.
2) Analyze and think first, then start overhaul
For the repair of the fault-sensing melting furnace, first ask the fault before and after the fault and the phenomenon of failure, according to the situation and clues provided by the user, then carefully analyze the circuit (this is especially important for beginners), get rid of Inductive melting furnace circuit principle and the role of components, to achieve a good number of points, targeted.
When dealing with the fault of the induction melting furnace on site, the operator should first be required to maintain the fault state on the site as much as possible without any treatment, which is helpful for quickly and accurately analyzing the cause of the fault. At the same time, carefully inquire about the fault indication situation, the fault phenomenon and the background of the fault, and make a preliminary judgment accordingly to determine the solution for troubleshooting on site.
When dealing with faults in the induction melting furnace on site, it is first necessary to verify the accuracy and completeness of the various conditions provided by the operator to verify the accuracy of the preliminary judgment. Due to the level of the operator, there are many cases where the fault condition is unclear or even completely inaccurate. Therefore, do not rush to handle the situation. The situation should be carefully investigated to avoid damage to the site and increase the difficulty of troubleshooting.
The failure type is determined based on the known fault condition to determine the fault principle. Since most faults are indicated. Therefore, in general, the diagnostic manual and instruction manual accompanying the induction melting furnace can list the various possible causes of the failure. Then investigate a variety of possible causes and find out the real cause of the failure. This is also a comprehensive test of the familiarity, knowledge level, practical experience and analytical judgment of the induction melting furnace. Some troubleshooting methods may be simple. Some faults are often complicated. A series of preparations are required, such as tools, instrumentation preparation, partial disassembly, component repair, component procurement, and even troubleshooting. The formulation of the steps, etc.
Before repairing, you should know the situation when the fault occurs, such as whether the power supply voltage is stable, whether there is collision, whether it is wet, whether there is abnormal smell or the like, and make a preliminary judgment of the fault according to the obtained information, so as to be aware of it. Before preparing to disassemble, check whether the voltage at the power supply terminal is normal. Then check whether the buttons and knobs of the induction melting furnace panel are normal and there is no obvious dull and weak. Finally, the type, age, and environmental conditions of the fault-induced melting furnace should be recorded.
The cause of the induction melting furnace failure may be multi-faceted, and the phenomenon of failure and the time of occurrence may be uncertain. To find a fault, first analyze the possible causes, and list the relevant scope, and find the technical data of the relevant scope as a theoretical guide. For relatively unfamiliar fault-induced melting furnaces, do not rush to start, should be familiar with the circuit principle and structural characteristics, and abide by the corresponding rules. Before disassembling, be fully familiar with the function, position, connection method and relationship with other devices around each electrical component. In the absence of an assembly drawing, sketches should be made and marked when disassembled.
3) First external, rear internal
The inductive melting furnace should be inspected for obvious cracks and defects, and the maintenance history and service life should be known. The peripheral circuits and electrical components of the induction melting furnace should be inspected first, especially if some switches and knobs outside the induction melting furnace are in position. Properly, external leads, sockets have no open circuit, short circuit phenomenon, etc. When it is confirmed that the external electrical components of the induction melting furnace are normal, the inside of the induction melting furnace is inspected. External fault factors should be excluded before disassembly, and internal faults are listed. The possible factors can only be disassembled after being determined to be faults in the induction melting furnace. Otherwise, the blind disassembly may further expand the fault. Only after excluding external equipment, wiring faults and other reasons, the internal maintenance can be carried out to avoid unnecessary Disassembled. After opening the induction melting furnace, carefully check the internal components for obvious damage such as damage, breakdown, burnt, and discoloration. Secondly, it is important to check whether the components are detached, soldered, or loose.
When performing board inspection, if conditions permit, it is best to use a good board as the reference to be repaired as a reference, and then use the measuring instrument to detect the relevant parameters to compare the two boards. The comparison test point can be started from the port of the board, and then the comparison is made between the table and the inside to judge the fault location.
4) First mechanical, after electrical
In the event of a failure of the induction melting furnace, an electrical inspection is performed only after it is determined that the mechanical part is not faulty. The integrity of the mechanical part should be checked first, and then the combination of the electronic circuit and the electromechanical unit should be checked. Often mechanical components fail that affect the electrical system, and the functionality of many electrical components does not work. Do not be confused by surface phenomena. Failure of the induction melting furnace is not entirely an electrical problem, and may be caused by a mechanical component failure. Therefore, first
Overhaul the failure of the mechanical part, and then eliminate the failure of the electrical part, often get twice the result with half the effort.
5) Simple first, then complicated
When troubleshooting the induction melting furnace, it is necessary to use the most simple and expert method to deal with it, and then use complicated and accurate methods. When troubleshooting, first eliminate the intuitive, obvious, simple and common faults, and then eliminate the difficult faults that have been difficult to handle. Induction melting furnaces are often prone to the same type of failure, a "common problem." Since “common diseases” are common and accumulated experience is abundant, they can be quickly eliminated, so that it is rare to concentrate and time exclusion.