Electrical troubleshooting method analysis

Troubleshooting basis

The basis for troubleshooting is the necessary conditions for troubleshooting. To thoroughly troubleshoot problems and solve the problems faced in practice, we must make clear the causes of failures. If we want to quickly identify the causes of failures, in addition to constantly accumulating experience in our work, it is more important to be able to theoretically analyze them. , Explain the cause of the accident, use theory to guide one's own operation, flexibly use the basic knowledge grasped and combine the actual work sometimes to be more than sufficient. However, the improvement of the technical level and the accumulation of maintenance experience require a long process.

1. Quality requirements for maintenance personnel

Electrical equipment is a technology-intensive and knowledge-intensive mechatronic product. Its advanced technology, complex structure, and high price often play a key role in production. Therefore, it has certain requirements for maintenance personnel. The quality of maintenance work depends primarily on the quality of maintenance personnel. As a maintenance personnel, the following conditions must be met:

1 wide range of professional knowledge. Should have a degree of education above technical secondary school, master or understand the basic knowledge of computer principles, electronic technology, electrical principles, automatic control and power drag, detection technology, mechanical transmission and mechanical processing technology. It is necessary to understand electricity and understand it. Electricity includes both strong and weak electricity; machines include mechanical, hydraulic, and pneumatic technologies.

2 diligent in learning, good at analysis. Electrical maintenance personnel should be a person who is diligent in learning. Not only should they have a broader knowledge, but they also need to have an in-depth understanding of the electrical systems that they need to troubleshoot. Electrical maintenance personnel need an analytical mind. The cause of some failure phenomena is often not obvious. It involves various technologies such as mechanics, electricity, liquid and gas. Therefore, it is crucial to make correct analysis and judgment in the face of these numerous causes and phenomena of failure. In actual work, the time spent on brains is often longer than hands-on time. Once the failure point is identified, repair is relatively simple.

3 have strong hands-on skills and practical skills. The repair of electrical systems can not be separated from the actual operation, maintenance personnel should operate the system to be repaired, view the alarm information, check, modify the parameters, call the self-diagnostic function, manual and test operation of the machine tool; should use the maintenance Necessary tools, instruments and instruments. It is very important for maintenance personnel to be bold and careful, that is, to dare to do something, and to be careful and orderly. The so-called "mind-mindness" is to first familiarize yourself with the situation and work hands-on, and not to be blind and obstinate when it comes to overhauling; to be stable and accurate in the hands-on process.

2. The necessary technical information and technical preparation

Maintenance personnel should carefully organize and read important technical data about the electrical control system. The maintenance work is done well, and the speed of troubleshooting is mainly determined by the maintenance personnel's proficiency in the system and the proficiency in the use of technical data. The following are several aspects to talk about the technical information and technical preparation necessary for maintenance of electrical faults:

1 Problems with maintenance information

A common problem in the maintenance of electrical equipment is incomplete information, often only the electrical schematic of the strong part or the equipment manual. About the main control system of the equipment (such as the control schematic diagram of the Lincoln welder main board, the numerical control device of the numerical control system, the servo drive device, etc.), there is very little information. At most, there is only one operation manual, and the system structure, especially the circuit diagram is generally There will be no, and this will cause great difficulties for maintenance work. I think this problem can be solved in the following aspects:

a) When signing an equipment purchase contract, it is necessary to strive for equipment suppliers to provide as much information as possible for future maintenance (eg technical specifications for machine tool installation, use, operation and maintenance, including the operation panel layout of the machine tool And its operation, machine electrical diagrams, layout drawings, and wiring diagrams. Electrical maintenance personnel also need hydraulic circuit diagrams and pneumatic circuit diagrams of the machine tool.)

b) During the commissioning and acceptance phase of the equipment, maintenance personnel use the opportunity to learn from the technicians and commissioning personnel of the equipment manufacturer to record as much as possible, collect data, data and methods required for various maintenance, and collect and collect these data. For future reference.

c) Data may be collected through various means at ordinary times, for example, through relevant electrical magazines, technical books, through communication with colleagues or via the Internet, etc. to obtain the necessary information.

d) During routine maintenance, at the same time of inspection and repair, the faulty circuit shall be mapped out, verified and verified, and the faulty part shall be sorted out. Over time, the circuit diagrams of the parts that fail often will be sorted out.

e) Other, technical information on the components within the electrical control system, such as the list of components used in numerical control equipment, spare parts lists, and various general-purpose component manuals. Maintenance personnel should be familiar with a variety of commonly used components, if necessary, can quickly check the relevant components of the function, parameters and alternative models.

2 questions about necessary spare parts

For the maintenance of the electrical system, spare parts are an essential technical preparation method. If there is no replacement or use of spare parts in the event of a fault, it will virtually delay the troubleshooting time and increase the difficulty of maintenance. And maintenance personnel have some master control circuit board on hand, which will bring many conveniences to troubleshooting. The change of board method can often quickly determine that some difficult faults occur on that circuit board. The configuration of spare parts for electrical systems must be based on The actual situation, usually some fragile electrical components (such as: various specifications of fuses, melts, switches, brushes, there are prone to failure of different power SCR modules and printed circuit boards, etc.) should be Properly configured. There are no detailed discussions on the management of spare parts, and only a brief description of several solutions for repairing spare parts:

a) In the repair and maintenance, the replaced problematic components should be as much as possible under the conditional conditions.

Make repairs. When there is no condition, a professional maintenance department with repair conditions should also be commissioned to repair it.

b) Substitutes In most cases, many electrical components can be replaced with other components of similar specifications and models (eg contactors, thyristor modules, resistors, capacitors, fast fuses, regulators, triodes). , FETs, etc.). Maintenance personnel should master the working principle, characteristic parameters and alternative methods of the relevant electrical components.

c) During the production and transformation and repair, when an electrical component is broken, but no spare component can be purchased, in order not to affect the production, some minor changes to the circuit may be considered, and other components may be used to accomplish the same function. (For example, the rectifier on the main control board of an electrical control system in a coil shop is bad. In order to clarify the pins and functions of this integrated rectifier circuit, it is possible to use other components to build a circuit to complete its existing functions. It is possible to replace damaged devices without affecting the production process because the right parts can not be bought at one time).