I. Maintenance and Care Knowledge of CNC Equipment CNC equipment is a highly automated and complex advanced machining equipment, and is a key piece of equipment for enterprises. To maximize the efficiency of CNC equipment, correct operation and meticulous maintenance are essential to ensure its utilization rate. Correct operation can prevent abnormal wear and tear on machine tools and avoid sudden malfunctions; proper daily maintenance can keep the equipment in good technical condition, slow down the deterioration process, and promptly detect and eliminate potential faults, thereby ensuring safe operation. 1. Issues to be aware of when using CNC equipment 1.1 Operating environment of CNC equipment To improve the service life of CNC equipment, it is generally required to avoid direct sunlight and other heat radiation, and to avoid excessively humid, dusty, or corrosive environments. Corrosive gases can easily corrode and deteriorate electronic components, causing poor contact or short circuits between components, affecting the normal operation of the equipment. Precision CNC equipment should be kept away from equipment with high vibration, such as punch presses and forging equipment. 1.2 Power Supply Requirements To avoid large power fluctuations (greater than ±10%) and potential instantaneous interference signals, CNC equipment generally uses dedicated power lines (such as a separate line from the low-voltage distribution room for the CNC machine tool) or adds voltage stabilizing devices, which can reduce the impact of power quality and electrical interference. 1.3 Operating Procedures Operating procedures are one of the important measures to ensure the safe operation of CNC machine tools. Operators must operate according to the operating procedures. When a machine tool malfunctions, the operator should preserve the scene and truthfully explain the situation before and after the malfunction to the maintenance personnel to facilitate analysis, diagnosis, and timely troubleshooting. Furthermore, CNC machine tools should not be stored unused for extended periods. They should be fully utilized after purchase, especially during the first year of use, to expose any vulnerable points prone to failure as early as possible, allowing them to be addressed within the warranty period. When not performing machining tasks, CNC machine tools should be powered on periodically, ideally 1-2 times per week for about one hour each time. This utilizes the machine tool's own heat to reduce internal humidity, preventing electronic components from becoming damp. It also allows for timely detection of battery alarms, preventing the loss of system software and parameters. [b]2. Maintenance and Upkeep of CNC Machine Tools[/b] CNC machine tools come in many types, each with different characteristics due to variations in function, structure, and system. Their maintenance content and rules also differ. Specific maintenance should be based on the machine tool type, model, and actual usage, referring to the machine tool's instruction manual to develop and establish a necessary periodic and graded maintenance system. Below are some common and general daily maintenance points. 2.1 CNC System Maintenance 1) Strictly adhere to operating procedures and daily maintenance protocols. 2) Minimize opening the doors of the CNC cabinet and electrical control cabinet. The air in machining workshops typically contains oil mist, dust, and even metal powder. If these fall onto circuit boards or electronic components within the CNC system, they can easily cause a decrease in insulation resistance between components, and even damage to components and circuit boards. Some users open the CNC cabinet doors in summer to allow the CNC system to operate under overload conditions for extended periods, which is highly inadvisable and will ultimately lead to accelerated damage to the CNC system. 3) Regularly clean the CNC cabinet's cooling and ventilation system. Check that all cooling fans on the CNC cabinet are functioning properly. Check the air duct filters for blockages every six months or quarter. Excessive dust accumulation on the filters, if not cleaned promptly, can cause excessively high temperatures inside the CNC cabinet. 4) Regular maintenance of the CNC system's input/output devices. CNC machine tools manufactured before the 1980s mostly have photoelectric paper tape readers. If the reading section is contaminated, it will cause errors in the read information. Therefore, the photoelectric reader must be maintained according to regulations. 5) Regular Inspection and Replacement of DC Motor Brushes: Excessive wear of DC motor brushes can affect motor performance and even cause damage. Therefore, motor brushes should be inspected and replaced regularly. CNC lathes, CNC milling machines, machining centers, etc., should be inspected annually. 6) Regular Replacement of Storage Batteries: Most CNC systems have rechargeable battery maintenance circuits for CMOS RAM storage devices to ensure that the memory contents are maintained when the system is not powered on. Under normal circumstances, even if it has not yet failed, it should be replaced annually to ensure normal system operation. Battery replacement should be performed while the CNC system is powered on to prevent loss of information in the RAM during replacement. 7) Maintenance of Spare Circuit Boards: Spare printed circuit boards that are not used for a long time should be periodically installed in the CNC system and powered on for a period of time to prevent damage. 2.2 Maintenance of Mechanical Components 1) Maintenance of the Main Drive Chain: Regularly adjust the tension of the spindle drive belt to prevent slippage and loss of rotation; check the constant temperature oil tank for spindle lubrication, adjust the temperature range, replenish oil in time, and clean the filter; after long-term use, the tool clamping device in the spindle may develop gaps, affecting tool clamping, and the displacement of the hydraulic cylinder piston needs to be adjusted in time. 2) Maintenance of the Ball Screw Thread Pair: Regularly check and adjust the axial clearance of the ball screw thread pair to ensure reverse transmission accuracy and axial stiffness; regularly check whether the connection between the ball screw and the bed is loose; replace any damaged ball screw protective devices in time to prevent dust or chips from entering. 3) Maintenance of the tool magazine and tool changing robot: It is strictly forbidden to load overweight or overlength tools into the tool magazine to avoid tool drops or collisions between the tool and the workpiece or fixture during tool changing. Regularly check the tool magazine's zero-return position and the machine tool spindle's return-to-tool-changing-point position, and adjust them promptly. When starting the machine, allow the tool magazine and robot to run idle to check the normal operation of each part, especially the limit switches and solenoid valves. Check the reliability of the tool locking on the robot; address any abnormalities promptly. 2.3 Hydraulic and pneumatic system maintenance: Regularly clean or replace the filters or filter screens of each lubrication, hydraulic, and pneumatic system; regularly test and change the hydraulic oil in the hydraulic system; regularly drain water from the pneumatic system's filter screens. 2.4 Machine tool accuracy maintenance: Regularly check and calibrate the machine tool's level and mechanical accuracy. There are two methods for calibrating mechanical accuracy: soft and hard. The soft methods mainly involve compensation through system parameters, such as lead screw backlash compensation, coordinate positioning accuracy point compensation, and machine tool return-to-reference point position correction. Hard methods are generally performed during machine tool overhauls, such as guide rail scraping and ball screw nut pair preload adjustment backlash. [b]II. Basic Conditions for Maintenance Work[/b] CNC machine tools range in price from hundreds of thousands to tens of millions of yuan. They are generally key equipment in critical products and processes within enterprises. A machine malfunction and downtime often have significant impact and losses. However, people often focus more on the efficiency of such equipment, neglecting not only its proper use but also its maintenance and repair. The lack of attention to creating and investing in maintenance and repair conditions is common, with last-minute efforts to address malfunctions being frequent. Therefore, to fully utilize the benefits of CNC machine tools, we must prioritize maintenance work and create favorable maintenance conditions. Since most CNC machine tool malfunctions are electrical, electrical maintenance is particularly important. 1. Personnel Requirements The speed and quality of CNC machine tool electrical maintenance work depend crucially on the qualifications of the electrical maintenance personnel. (1) First, one must have a high sense of responsibility and good professional ethics. (2) One must have a broad knowledge base. One must learn and master the knowledge of various disciplines related to the electrical control of CNC machine tools, such as computer technology, analog and digital circuit technology, automatic control and drive theory, control technology, machining technology and mechanical transmission technology, and of course, the basic CNC knowledge mentioned in the previous section. (3) One should undergo good technical training. The study of the basic theory of CNC technology, especially the technical training for specific CNC machine tools, should first involve attending relevant training courses and practical training at the machine tool installation site, then learning from experienced maintenance personnel, and more importantly and for a longer period of time, self-study. (4) One must be willing to practice. One should actively engage in the maintenance and operation of CNC machine tools and improve analytical and hands-on abilities through continuous practice. (5) One must master scientific methods. To do a good job in maintenance, enthusiasm alone is not enough; one must also summarize and improve through long-term learning and practice, and extract scientific methods for analyzing and solving problems. (6) One must learn and master various commonly used instruments, meters and tools in electrical maintenance. (7) Master a foreign language, especially English. At least be able to understand technical documents. 2. Material conditions (1) Prepare general electrical spare parts and special electrical spare parts for a certain CNC machine tool. (2) Non-essential spare electrical components should be procured through fast and smooth channels. (3) Necessary maintenance tools, instruments, etc., preferably equipped with a laptop computer and necessary maintenance software. (4) Complete technical drawings and data for each CNC machine tool. (5) Technical archives for the use and maintenance of CNC machine tools. 3. About preventive maintenance The purpose of preventive maintenance is to reduce the failure rate. Its work content mainly includes the following aspects. (1) Personnel arrangement Assign dedicated operators, process personnel and maintenance personnel to each CNC machine tool. All personnel should continuously strive to improve their professional and technical level. (2) Establish rules and files Formulate operating rules for the specific performance and processing objects of each machine tool, establish work and maintenance files, and managers should frequently check, summarize and improve. (3) Daily maintenance A daily maintenance plan should be established for each CNC machine tool, including maintenance content (such as lubrication and wear of the coordinate axis transmission system, spindle lubrication, oil, water and air circuits, various temperature controls, balance system, cooling system, tension of transmission belts, cleaning of relay and contactor contacts, whether each plug and terminal is loose, ventilation of electrical cabinet, etc.) and maintenance cycle of each functional component and part (daily, monthly, semi-annually or irregularly). (4) Improve utilization If a CNC machine tool is idle for a long time, when it needs to be used, firstly, the static and dynamic transmission performance of each moving part of the machine tool will be affected by the solidification of grease, dust or even rust, which will reduce the accuracy of the machine tool. The blockage of the oil circuit system is a major problem. From an electrical point of view, since the entire electrical control system hardware of a CNC machine tool is composed of tens of thousands of electronic components, their performance and lifespan have great dispersion. From a macro perspective, it is divided into three stages: within one year, it is basically in the so-called "break-in" stage. During this stage, the failure rate is declining. If the machine tool is continuously started during this period, the "break-in" task will be completed quickly, and the one-year maintenance period can be fully utilized. The second stage is the effective life stage, which is the stage of fully utilizing its efficiency. Under reasonable use and good daily maintenance, the machine tool can operate normally for at least five years. The third stage is the system life aging stage, where electrical hardware failures will gradually increase, and the average lifespan of the CNC system is about 8 to 10 years. Therefore, during periods without processing tasks, it is best to run the machine tool at a low speed, or at least power on the CNC system frequently, or even every day. [b]III. Maintenance and Troubleshooting Techniques[/b] [b]1. Classification of Common Electrical Faults[/b] Electrical faults of CNC machine tools can be classified according to the nature, appearance, cause, or consequence of the fault. (1) Based on the location of the fault, they are divided into hardware faults and software faults. Hardware faults refer to the abnormal state or even damage of electronic components, electrical devices, printed circuit boards, wires and cables, connectors, etc., which require repair or even replacement to eliminate the fault. Software faults generally refer to faults generated in the PLC logic control program, which require inputting or modifying certain data or even modifying the PLC program to eliminate the fault. Part machining program faults also belong to software faults. The most serious software fault is the damage or even loss of the CNC system software, which can only be resolved by contacting the manufacturer or its service organization. (2) Based on whether there is an indication when the fault occurs, it is divided into faults with diagnostic indications and faults without diagnostic indications. Modern CNC systems are designed with perfect self-diagnostic programs that monitor the software and hardware performance of the entire system in real time. Once a fault is detected, it will immediately alarm or display a brief text description on the screen. Combined with the diagnostic manual provided by the system, not only can the cause and location of the fault be found, but also the method of elimination can be suggested. Machine tool manufacturers will also design relevant fault indications and diagnostic manuals for specific machine tools. The above two parts of faults with diagnostic indications, plus various indicator lights on various electrical devices, make it easier to eliminate most electrical faults. Faults without diagnostic indications are partly caused by the incompleteness of the above two diagnostic programs (such as switches not closing, loose connections, etc.). These types of faults rely on the working process before the fault occurs, the fault phenomenon and consequences, and the maintenance personnel’s familiarity with the machine tool and technical level to analyze and eliminate them. (3) Based on whether the fault is destructive when it occurs, it is divided into destructive faults and non-destructive faults. For destructive faults, which damage the workpiece or even the machine tool, it is not allowed to be reproduced during maintenance. At this time, it can only be eliminated by checking and analyzing the phenomenon when the fault occurs. The technical difficulty is high and there is a certain risk. If it may damage the workpiece, the workpiece can be removed and the fault process can be reproduced, but it should be done with great care. (4) Based on the probability of the fault occurring, it is divided into systematic faults and random faults. Systematic faults refer to certain faults that will definitely occur as long as certain conditions are met; while random faults refer to faults that occur occasionally under the same conditions. The analysis of these types of faults is more difficult. They are usually related to the local loosening and misalignment of the machine tool’s mechanical structure, the drift of some electrical workpiece characteristics or the reduction of reliability, and the excessively high internal temperature of the electrical device. The analysis of these types of faults requires repeated tests and comprehensive judgment to eliminate them. (5) Measured by the motion quality characteristics of the machine tool, it is a fault of decreased motion characteristics of the machine tool. In this situation, although the machine tool can operate normally, it cannot produce qualified workpieces. For example, the machine tool's positioning accuracy may be out of tolerance, the reverse dead zone may be too large, or the coordinate movement may be unstable. These types of faults require the use of testing instruments to diagnose the mechanical and electrical components causing the error, and then the fault can be eliminated through optimal adjustments to the mechanical transmission system, CNC system, and servo system. 2. Fault Investigation and Analysis This is the first and crucial stage of troubleshooting. The following tasks should be performed: ① Inquiry and Investigation: Upon receiving information about a machine tool malfunction requiring troubleshooting, the operator should be instructed to maintain the fault state as much as possible without taking any action. This facilitates a rapid and accurate analysis of the fault's cause. Simultaneously, carefully inquire about the fault indications, symptoms, and background information to make a preliminary judgment. This will help determine the tools, instruments, drawings, spare parts, etc., needed for on-site troubleshooting, reducing travel time. ② On-site Inspection: Upon arrival at the site, the accuracy and completeness of the information provided by the operator should be verified to confirm the accuracy of the preliminary judgment. Due to the operator's skill level, there are frequent instances where the description of the fault condition is unclear or even completely inaccurate. Therefore, upon arriving at the site, do not rush to handle the situation. Carefully re-investigate all aspects to avoid damaging the site and increasing the difficulty of troubleshooting. ③ Fault Analysis: Based on the known fault condition, analyze the fault type according to the fault classification method described in the previous section to determine the troubleshooting principle. Since most faults have indications, generally, referring to the CNC system diagnostic manual and user manual provided with the machine tool, multiple possible causes of the fault can be listed. ④ Determining the Cause: Investigate multiple possible causes to find the true cause of the fault. This is a comprehensive test of the maintenance personnel's familiarity with the machine tool, knowledge level, practical experience, and analytical judgment ability. ⑤ Troubleshooting Preparation: Some faults may be easy to troubleshoot, while others are more complex and require a series of preparatory work, such as preparing tools and instruments, partial disassembly, repairing parts, purchasing components, and even formulating a troubleshooting plan. The process of investigating, analyzing, and diagnosing faults in the electrical system of CNC machine tools is also the process of troubleshooting. Once the cause is identified, the fault is almost eliminated. Therefore, the methods of fault analysis and diagnosis become very important. The commonly used diagnostic methods for electrical faults are summarized below. (1) Visual inspection method This is a method that must be used at the beginning of fault analysis, which is to use sensory inspection. ① Inquiry Carefully inquire about the process of fault generation, fault symptoms and fault consequences from the personnel at the fault site, and may need to be asked multiple times throughout the entire analysis and judgment process. ② Visual inspection Check whether the working status of each part of the machine tool is in normal condition (e.g., the position of each coordinate axis, spindle status, tool magazine, robot position, etc.), whether each electrical control device (such as CNC system, temperature control device, lubrication device, etc.) has alarm indication, check whether the fuse is burnt, whether the components are charred, cracked, or the wires and cables are detached, and whether the position of each operating element is correct, etc. ③ Touch Under the condition of power failure of the whole machine, the installation status of each main circuit board, the plug status of each plug socket, and the connection status of each power and signal wire (such as the wiring of servo and motor contactor) can be touched to find the possible causes of the fault. ④ Powering on: This refers to powering on the device to check for smoke, sparks, abnormal sounds, smells, and whether there are overheated motors and components. Power should be cut off immediately upon detection. (2) Instrument inspection method: Use conventional electrical instruments to measure the voltage of each AC and DC power supply, as well as related DC and pulse signals, to find possible faults. For example, use a multimeter to check the power supply status and measure the relevant signal status measurement points on certain circuit boards. Use an oscilloscope to observe the amplitude, phase, and even presence of related pulse signals. Use a PLC programmer to find the fault location and cause in the PLC program. (3) Signal and alarm indication analysis method: ① Hardware alarm indication: This refers to the various status and fault indicator lights on various electronic and electrical devices, including CNC systems and servo systems. By combining the indicator light status and corresponding function descriptions, the indication content, fault cause, and troubleshooting method can be obtained. ② Software alarm indication: As mentioned above, faults in system software, PLC programs, and machining programs usually have alarm displays. By referring to the corresponding diagnostic manual based on the displayed alarm number, the possible fault cause and troubleshooting method can be obtained. (4) Interface Status Inspection Method: Modern CNC systems often integrate PLCs, and the CNC and PLC communicate with each other through a series of interface signals. Some faults are related to incorrect or lost interface signals. Some of these interface signals can be displayed by indicator lights on the corresponding interface board and input/output board, while others can be displayed on the CRT screen through simple operation. All interface signals can be retrieved using a PLC programmer. This inspection method requires maintenance personnel to be familiar with both the interface signals of the machine tool and the application of the PLC programmer. (5) Parameter Adjustment Method: CNC systems, PLCs, and servo drive systems all have many modifiable parameters to adapt to the requirements of different machine tools and different working states. These parameters not only match the electrical systems with the specific machine tool, but are also necessary to optimize the various functions of the machine tool. Therefore, any change in parameters (especially analog parameters) or even loss is not allowed; and changes in the mechanical or electrical performance caused by the long-term operation of the machine tool will break the initial matching state and optimization state. This type of fault often refers to the latter type of fault in the fault classification section, which requires readjustment of one or more related parameters to eliminate the fault. This method places high demands on maintenance personnel. They must not only be very familiar with the main parameters of the specific system, know its location and function, but also have rich experience in electrical debugging. (6) Spare Parts Replacement Method When the fault analysis results are concentrated on a certain printed circuit board, it is very difficult to pinpoint the fault to a certain area or even a certain component due to the continuous expansion of circuit integration. In order to shorten the downtime, if there are identical spare parts available, the spare parts can be replaced first, and then the faulty board can be checked and repaired. The following issues should be noted when replacing spare parts. Any replacement of spare parts must be carried out under power-off conditions. Many printed circuit boards have some switch or short-circuit bar settings to match actual needs. Therefore, when replacing spare parts, the original switch positions and settings must be recorded, and the new board must be set in the same way. Otherwise, an alarm will be generated and the board will not work. The replacement of some printed circuit boards also requires certain specific operations after replacement to complete the establishment of the software and parameters. This requires careful reading of the corresponding circuit board's instruction manual. Some printed circuit boards cannot be easily removed, such as boards containing working memory or spare battery boards, as they may lose useful parameters or programs. When replacement is necessary, the relevant instructions must be followed. Given the above conditions, before removing the old board to replace the new board, you must carefully read the relevant information, understand the requirements and operating procedures before proceeding, so as to avoid causing greater damage. (7) Cross-swap method When a faulty board is found or it is uncertain whether it is a faulty board and there is no spare part, two identical or compatible boards in the system can be swapped for inspection, such as the swapping of two coordinate instruction boards or servo boards to determine the faulty board or faulty part. Special attention should be paid to this cross-swap method. Not only should the hardware wiring be correctly swapped, but a series of corresponding parameters should also be swapped. Otherwise, not only will the purpose not be achieved, but new faults will be generated, causing confusion in thinking. It is necessary to consider everything in advance, design a software and hardware swapping scheme, and swap and check accurately. (8) Special handling methods Today's CNC systems have entered the PC-based and open development stage, with increasingly rich software content, including system software, machine tool manufacturer software, and even user-owned software. Due to some unavoidable problems in the design of software logic, some fault states are impossible to analyze, such as system crashes. For such fault phenomena, special measures can be taken to handle them, such as powering off the entire machine, pausing briefly, and then powering it on again. Sometimes this may eliminate the fault. Maintenance personnel can explore its patterns or other effective methods in their long-term practice. 3. Electrical maintenance and troubleshooting This is the second stage of troubleshooting, which is the implementation stage. As mentioned above, the process of analyzing electrical faults is also the process of troubleshooting. Therefore, some common troubleshooting methods for electrical faults have been comprehensively introduced in the analysis methods in the previous section. This section lists a few common electrical faults for a brief introduction for maintenance personnel to refer to. (1) Power supply The power supply is the energy source for the normal operation of the maintenance system and even the entire machine tool. Its failure or malfunction will result in data loss and machine downtime. In severe cases, it will damage parts or even the entire system. Western countries have abundant electricity and high grid quality, so their electrical systems have less consideration for power supply design. This is slightly insufficient for my country's power supply network, which has large fluctuations and high harmonics. In addition, due to some human factors, power supply-related faults are inevitable. When designing the power supply system of CNC machine tools, we should try to: provide independent distribution boxes and not share them with other equipment. Three-phase AC voltage stabilizers should be provided in areas with poor power grid quality. The power supply should have good grounding at the beginning. The three-phase power supply entering the CNC machine tool should adopt a three-phase five-wire system, and the neutral line (N) and grounding (PE) should be strictly separated. The layout of electrical components in the cabinet and the laying of AC and DC wires should be mutually isolated. (2) CNC system position loop fault ① Position loop alarm. It may be due to an open circuit in the position measurement loop; damage to the measuring element; absence of the interface signal for position control establishment, etc. ② The coordinate axis moves without instructions. It may be due to excessive drift; positive feedback of the position loop or speed loop; open circuit of the feedback wiring; damage to the measuring element. (3) The machine tool coordinate cannot find the zero point, which may be due to the zero direction being far from the zero point; the encoder is damaged or the wiring is open; the grating zero point mark is shifted; or the zero return deceleration switch is malfunctioning. (4) The dynamic characteristics of the machine tool deteriorate, the workpiece processing quality decreases, and the machine tool even vibrates at a certain speed. One of the most likely causes is that the mechanical transmission system has too large a clearance or even severe wear, or the guide rail is not sufficiently lubricated or even worn. For the electrical control system, it may be that the speed loop, position loop and related parameters are no longer in the optimal matching state. After the mechanical fault is basically eliminated, it should be readjusted. (5) There are two possible situations for occasional machine stop failures: one is that the problem in the relevant software design, as mentioned above, causes the machine stop failure under certain specific operation and function operation combinations. In general, the machine tool will disappear after power is turned off and then powered on again. The other situation is caused by environmental conditions, such as strong interference (power grid or peripheral equipment), excessive temperature, excessive humidity, etc. These environmental factors are often overlooked. For example, in southern regions, machine tools are often placed in ordinary factory buildings or even near open doors, with electrical cabinets running for extended periods, and near equipment that generates dust, metal shavings, or water mist. These factors can not only cause malfunctions but, in severe cases, damage the system and the machine tool, so it is essential to address them. This article will not elaborate further due to space limitations; readers can refer to the accompanying documentation for CNC machine tools and other articles specifically addressing various malfunctions. 4. Summary and Improvement Work After Troubleshooting The summary and improvement work following the repair, analysis, and troubleshooting of electrical faults in CNC machine tools is the third and crucial stage of troubleshooting and should be given sufficient attention. The main contents of the summary and improvement work include: detailed records of all problems encountered throughout the entire process from the occurrence, analysis, and troubleshooting of the fault, the various measures taken, the relevant circuit diagrams, parameters, and software involved, and the error analysis and troubleshooting methods, along with the reasons for their ineffectiveness. In addition to filling in the maintenance file, more detailed information should be written in a separate document. Maintenance personnel with the necessary resources should identify universally applicable aspects from typical troubleshooting practices and use them as research topics for theoretical exploration, writing papers to improve their skills. This is especially important when troubleshooting faults is achieved somewhat by chance rather than through rigorous systematic analysis; post-troubleshooting analysis is even more crucial in such cases. It's essential to summarize all necessary diagrams and written materials used in the troubleshooting process, addressing any deficiencies by finding ways to supplement them afterward and studying them in the future. Identify any knowledge gaps during troubleshooting, develop a learning plan, and strive to fill those gaps as quickly as possible. Identify any deficiencies in tools, instruments, and spare parts, and replenish them when possible. The benefits of summarizing and improving work include: rapidly enhancing the theoretical level and maintenance capabilities of maintenance personnel; increasing the speed of repairing recurring faults; facilitating the analysis of equipment failure rates and maintainability, improving operating procedures, and extending machine tool lifespan and utilization; addressing shortcomings in the original electrical design of machine tools; and enabling resource sharing, as summarized data can serve as parameter data and training materials for other maintenance personnel.