What are the causes of equipment failure during the interlock test

1. External damage. For example, the construction of unqualified cable laying and installation is easy to cause mechanical damage, and it is easy to damage the underground cable in civil construction.

Sometimes if the damage is not serious, it may lead to a complete breakdown failure of the damaged part for several months or even years, and sometimes it may cause serious damage and a short circuit fault may occur, which directly affects the safe production of electrical units. 2. The insulation is damp. For example:

Cable joints are made unqualified and in humid climates, joints can make water or water vapor, under the action of the electric field for a long time r stratum water tree mixing, dielectric strength gradually caused damage to the failure of the cable. 3. Chemical corrosion. In areas of acid-alkali interaction, due to long-term exposure to chemical or galvanic corrosion by armored cables, wires or corroded protective layers, the outer protective layer is often caused, resulting in poor insulation of the protective layer and also leading to cable failure.

4. Long-term overload operation. Overload operation, due to the thermal effect of the load current through the cable will inevitably lead to heating in the conductor, at the same time, the skin effect and the eddy current loss of the charge, the dielectric loss of the steel armor can also generate additional heat, thus making the cable temperature. 5. Cable joint failure.

Cable joints are the weakest link of the cable that leads to frequent cable gland failures, direct negligence. In the manufacturing method of cable joints, if the crimping is not tight, the heating is not sufficient, which leads to the reduction of the insulation of the cable head, resulting in accidents.

When the boiler is turned off after two induced air grids or two supply fans in operation trip at the same time, the furnace chamber ** or equipment damage accident will occur if the fuel ** is not stopped immediately. Therefore, the boiler auxiliary must be equipped with interlocks. When the supply and induced draft fan fails to trip, it can automatically stop the powder feeder, coal feeder and other equipment.

Causes of mechanical equipment failures.

1.The reason for the failure of the belt drive is that the force of the belt acting on the shaft is large, and the long-distance transmission is realized, and the belt is worn, torn or even broken for a long time, which has a greater impact on the bearing.

2.The main causes of gear transmission failure are tooth wear and pitting corrosion caused by poor lubrication working environment. The tooth surface meshing is not in place, resulting in tooth root breakage, plastic deformation and so on. Too much.

3.Chain drive, mainly due to poor lubrication working environment caused by chain sleeve wear, too much, can you ask targeted questions.

Ways to protect against mechanical breakdowns.

If the causes of various failures can be correctly analyzed and effective and targeted preventive measures can be taken to effectively prevent mechanical failures and prolong the service life of machinery.

1. Ensure normal working load:

Be careful not to work beyond the maximum load that the machine can bear, and use the machine within your means. It is necessary to ensure the uniform addition and decrease of the mechanical load as much as possible, so that the machinery is in a relatively smooth load change, specifically, it is necessary to increase or decrease the throttle more evenly to prevent the ups and downs of the engine and working device.

2. Ensure the reasonable lubrication of machinery

Normal and reasonable lubrication is one of the effective measures to reduce mechanical failure. To this end, it is necessary to choose lubricants reasonably, according to the different types of machinery and application structures, to select the appropriate quality group according to the requirements of the machinery, to select the appropriate quality grade according to the requirements of the machinery, and to select the appropriate lubricant grade according to the working environment of the machinery and different seasons. In use, neither low-grade lubricants can be used, nor can they be replaced by other types of lubricants, and inferior products cannot be used.

3. Timely maintenance:

There will inevitably be a variety of failures in the process of using machinery. Among these faults, some faults may have a very small impact on machinery and equipment, and some are more serious, and even cause major accidents such as machine destruction and death. The failure should be dealt with in a timely manner, and the so-called timely treatment is to carry out regular maintenance and repair of machinery in accordance with the maintenance procedures, and the maintenance and repair of various groups must be carried out as required; In the process of use, it is necessary to strengthen the regular and irregular inspection of construction machinery, keep abreast of the operation of machinery, and deal with temporary failures in a timely manner.

Fourth, take correct technical measures and organizational management measures:

As the organization and management personnel and operators of construction machinery, they should pay attention to ensure that the machinery is prevented from damage, deformation and corrosion during transportation and storage; Strict daily maintenance of machinery, so that the machinery is in good technical condition; It is necessary to educate operators to correctly use and operate various construction machinery, reduce and prevent mechanical failures caused by human error; It is necessary to carefully maintain the machinery, to do the correct and reasonable regular and irregular maintenance, to keep the machinery clean and clean, to regularly check the technical status of the machinery, to find abnormal timely treatment, for loose and out of balance parts in time fastening and adjustment, to some wearing parts for preventive replacement, etc.

Sources of abrasion.

BAI caused by abnormal operation.

Caused by an unlawful alteration of its function.

Overloaded.

Potential undesirable factors in the design of the DU.

Poor maintenance. dao

Extended answer: equipment failure generally refers to the event or phenomenon of equipment losing or reducing its specified function, which is manifested as abnormal production and operation of equipment, which refers to the loss of original accuracy or performance of some parts of the equipment, so that the equipment can not operate normally, and the technical performance is reduced, resulting in the interruption of production of the equipment or the reduction of efficiency and affecting production. Strengthen equipment maintenance and repair, timely grasp the wear and tear of parts, and repair and replace parts before entering the stage of severe wear and tear, so as to prevent economic losses caused by failure and shutdown.

Failures caused by the wearing of moving parts that exceed the limit values at a certain time. The so-called wear refers to the phenomenon that the size, shape and surface quality of the machinery change under the action of friction when the dual surfaces of the machinery are in contact with each other to move each other in the process of work. According to its formation mechanism, it can be divided into four types: adhesion wear, surface fatigue wear, corrosion wear, and fretting vibration wear.

It can be caused by uneven material properties; or caused by improper processing technology (such as improper treatment in forging, casting, welding, grinding, heat treatment and other processes, it is easy to produce brittle fracture); It can also be caused by harsh environments; If the temperature is too low, the mechanical properties of the material are reduced, mainly referring to the reduction of impact toughness, so the cryogenic container (below -20) must choose a material with an impact value greater than a certain value. For example, radiation can also cause embrittlement of materials, which can lead to brittle fractures.

1.Caused by abrasion.

The equipment also has a life phenomenon, and after reaching a certain level of use, it will die, and there is no need to repair it, only to renew it. Nowhere is this more evident than in high-precision equipment.

The wear and tear of equipment can be divided into two types: tangible wear and invisible wear.

Physical wear refers to the physical and chemical changes caused by the material wear and tear that occurs during the use of the equipment or due to the natural erosion of the environment.

Invisible wear refers to: due to the progress of science and technology, the use value of equipment is reduced, or even eliminated.

2.Caused by abnormal operation.

Almost all equipment has strict requirements for the sequence of action, and you must not operate it at will, and failure to comply with the operating procedures will only directly lead to or accelerate its failure. In on-site management activities, unskilled newcomers, wrong operations and settings are the most direct "killers" of damaged equipment.

3.Caused by an unlawful alteration of its function.

If the device is designed with a potential function, then it is not a big problem to transform it, but I am afraid that there is no such function, but I insist on imposing this function, which will kill the "life" of the device.

4.Overloaded.

People stop stopping, 24 hours a day, 365 days a year, if it is not broken, it will not stop; If it is not broken, it will not be repaired, and it is in a hurry to turn over, which is a typical method of using equipment in a "cottage factory". Although some equipment is in an overload state, there is no fault for the time being, but the overload operation makes the equipment fatigue, aging and wear process is greatly accelerated, and ultimately leads to shortened life.

5.Potential design pitfalls.

At the end of the design, the relevant matters can be fully discussed and hurriedly launched, resulting in many failures in the use stage, so the second patch design and the third patch design ......, which has not been finalized for a long time. Such a device is not safe to use.

6.Poor maintenance practices.

First-class equipment, second-rate operation, third-rate maintenance. Don't treat the equipment as a "person", only call it work, don't give "food" to eat, and don't even do the most basic cleaning, so that small failures gradually evolve into big failures.

1. Natural failure: During the operation of electrical equipment, its electrical equipment often has to bear the influence of many unfavorable factors, such as mechanical vibration in the process of electrical action; The effect of overcurrent accelerates the insulation aging and deterioration of electrical components; burning loss of the arc; natural wear and tear of long-term action; the influence of ambient temperature and humidity; erosion of harmful media; quality problems with the components themselves; Natural life and other reasons, the above reasons will make it inevitable that there will be some electrical failures of one kind or another and affect the normal operation of the equipment. Therefore, strengthening daily maintenance and overhaul can make electrical equipment not fail or less in a long period of time, but it must not be mistaken that electrical equipment failures and objective existence are inevitable, so we ignore daily maintenance and regular maintenance work.

2. Man-made faults, electrical equipment in the process of operation, due to the damage caused by undue mechanical external force or due to improper operation, unreasonable installation caused by failure, will also cause equipment accidents, and even endanger personal safety.

The structure of electrical equipment is different, there are many kinds of electrical components, and the factors that lead to electrical failures are varied, so the faults of electrical equipment are bound to be various. However, these failures can be broadly divided into two broad categories;

1. Faults with obvious appearance characteristics that are easy to be found, such as significant heating, smoke, scorching odor or sparks from motors and electrical appliances. This kind of failure is caused by overload, insulation breakdown, short circuit or grounding of the windings of motors and electrical appliances. When troubleshooting these faults, in addition to replacement or repair, it is also necessary to find out and eliminate the causes of said failures.

2. Faults without appearance characteristics, the main faults of this type of control circuit. In the electrical circuit, the fault is caused by improper adjustment of electrical components, failure of mechanical action, poor contact or detachment of contacts and crimping, damage to a small part, wire breakage, etc. The more complex the line, the more opportunities there are for such failures.

This kind of fault is small but often encountered, because there is no appearance of the characteristics, to find the fault point, it takes a long time to sing, sometimes it is also necessary to find out the fault point with the help of various measuring instruments and tools, and once the fault point is found, often only a simple adjustment or repair can immediately restore the normal operation of the machine tool, so whether the fault point can be quickly detected is the key to shorten the time when repairing this kind of fault.

Classification according to the process of occurrence and development of failures.

1. Sudden failure There is no obvious sign before the failure, and it is difficult to rely on early testing or testing. This kind of fault occurs for a short time and is generally destructive, such as the fracture of the rotor, the damage of equipment caused by personnel misoperation, etc., which belong to this type of failure; 2. Gradual failure of some parts of the equipment in the process of use due to fatigue, corrosion, wear, etc., the performance gradually decreases, and finally exceeds the allowable value and the failure occurs. This type of fault accounts for a considerable proportion of the problem, has a certain regularity, and can be prevented through early condition monitoring and fault preparation.

Categorized by what happened to the failure.

1. Early failure This kind of failure may be a defect in the design, processing or material, which is exposed in the early stage of the equipment operation. Or some parts such as gear pairs and other friction pairs need to go through a period of "running" to gradually improve the working situation. After this early failure is exposed, treated, and perfected, the failure rate begins to decline.

For predictive maintenance of early failures, it is recommended to use intelligent spot checkers;

2. Probationary period failure This is a failure that occurs during the life of the product, which is caused by unpredictable accidental factors such as load, external factors, operating conditions, etc., and system characteristics, internal factors, parts failure, structural damage, etc. The equipment is in this working state most of the time. At this point, the failure rate is essentially constant.

It is of great significance to monitor and diagnose faults during this period;

3. Later failure, also known as dissipative period failure, often occurs in the later stage of the equipment, due to the long-term use of the equipment, even beyond the service life of the equipment, due to the gradual wear and tear of the parts of the equipment, fatigue, aging and other reasons to degrade the system function, it is best to lead to sudden, dangerous, global failures of the system. During this period, the equipment failure rate is on the rise, through monitoring, diagnosis, and failure parts should be replaced in time to avoid accidents.