Repair operations

Test of strength

Those. repair

Medium renovation

Change of oil

Major renovation

5.2 Annual PPR schedule

The annual schedule of preventive maintenance of equipment makes it possible to establish only in what month a given piece of equipment will be installed and what type of repair will be carried out.

Based on the annual schedule of preventive maintenance, the planned labor costs for repairing the workshop equipment are calculated, which are entered into the labor cost sheet.

Does the enterprise have an annual schedule for preventive maintenance of equipment and monthly plans and schedules for repair of equipment by workshop?

If the station has a clearly developed annual schedule of preventive maintenance, the repair team is busy with work throughout the year. In the intervals between repairs of units, this group prepares, repairs and assembles spare parts and components.

This should be taken into account when drawing up the annual maintenance schedule.

The maintenance schedule is drawn up by the workshop mechanic together with the workshop manager, agreed with the chief mechanic of the plant and approved by the chief engineer of the plant.

The range of repair work is planned in accordance with the annual schedule of preventive maintenance of equipment assigned to the team, taking into account the technical condition of each machine and unit at the time of drawing up the work plan.

The duration of current repairs is established in advance for each workshop by an annual schedule of preventive maintenance. At the same time, it is taken into account that these repairs must be carried out during non-working hours, and if equipment downtime is inevitable, then it should not exceed the established standards.

Taking into account all the features of equipment operation, an annual schedule of preventive maintenance is developed. Based on the annual maintenance schedule, taking into account the technical condition of each piece of equipment, a work plan is drawn up for each team. The work plan is the main document that determines the scope of work according to the nomenclature, the labor intensity of repairs and maintenance, the team’s wage fund for the planned period, planned and unplanned downtime during repairs. It is also a document that reflects the team’s actual implementation of planned indicators.

2. System of scheduled preventive maintenance of equipment

The planned preventive form of organizing the repair of technological equipment throughout the world is recognized as the most effective and has found the greatest distribution. The development of a system for scheduled preventive maintenance of equipment began in the USSR in 1923. Currently, various versions of the preventive maintenance system are the basis for organizing the maintenance and repair of equipment at enterprises in most industries in the sphere of material production and service.

System of scheduled preventive maintenance of equipment- this is a set of planned organizational and technical measures for the care, supervision of equipment, its maintenance and repair. The purpose of these measures is to prevent progressively increasing wear, prevent accidents and maintain equipment in constant readiness for work. The PPR system involves carrying out preventive measures for maintenance and scheduled repair of equipment after a certain number of hours of its operation, while the alternation and frequency of activities are determined by the characteristics of the equipment and its operating conditions.

PPR system includes

Maintenance

and scheduled equipment repairs.

Maintenance- this is a set of operations to maintain the functionality of equipment when used for its intended purpose, during storage and transportation. Maintenance includes

routine maintenance between overhauls

and periodic preventive maintenance operations.

Routine maintenance between overhauls consists of daily monitoring of the condition of the equipment and compliance with the rules of its operation, timely adjustment of mechanisms and elimination of minor malfunctions that arise. These works are performed by the main workers and repair personnel on duty (mechanics, lubricators, electricians), as a rule, without equipment downtime. Periodic preventive maintenance operations regulated and carried out by repair personnel according to a pre-developed schedule without equipment downtime. Such operations include

inspections carried out to identify defects that must be eliminated immediately or during the next scheduled repair;

flushing and oil change provided for equipment with centralized and crankcase lubrication systems;

accuracy check performed by technical control and chief mechanic personnel.

Scheduled repairs includes

Maintenance

and major repairs.

Maintenance is carried out during the operation of the equipment in order to ensure its operability until the next scheduled repair (the next routine or major). Current repairs consist of replacing or restoring individual parts (parts, assembly units) of equipment and adjusting its mechanisms. Major renovation carried out with the aim of restoring the full or close to full resource of equipment (accuracy, power, productivity). Major repairs, as a rule, require repair work in stationary conditions and the use of special technological equipment. Therefore, it is usually necessary to remove the equipment from the foundation at the site of operation and transport it to a specialized department where major repairs are carried out. During a major overhaul, the equipment is completely disassembled, all its parts are checked, worn parts are replaced and restored, coordinates are aligned, etc.

The repair and maintenance system, depending on the nature and operating conditions of the equipment, can operate in different organizational forms:

in the form of a post-examination system,

periodic repair systems

or standard repair systems.

Post-examination system involves carrying out equipment inspections according to a pre-developed schedule, during which its condition is established and a list of defects is compiled. Based on the inspection data, the timing and content of the upcoming repairs are determined. This system is used for certain types of equipment operating under stable conditions.

Periodic repair system involves planning the timing and volume of repair work of all types based on a developed regulatory framework. The actual scope of work is adjusted relative to the standard based on the results of the inspection. This system is most common in mechanical engineering.

Standard repair system involves planning the volume and content of repair work based on precisely established standards and strict adherence to repair plans, regardless of the actual condition of the equipment. This system applies to equipment whose unscheduled shutdown is unacceptable or dangerous (for example, lifting and transport devices).

The effectiveness of the PPR system is largely determined by the development of its regulatory framework and the accuracy of the established standards. The standards of the enterprise's PPR system are differentiated by equipment groups. Basic repair standards are

repair cycles and their structure,

labor and material intensity of repair work,

material supplies for repair needs.

Repair cycle- this is the period of time from the moment the equipment is put into operation until the first major overhaul or between two consecutive major overhauls. The repair cycle is the smallest repeating period of equipment operation, during which all types of maintenance and repair are carried out in the established sequence in accordance with the structure of the repair cycle. The structure of the repair cycle establishes the list, quantity and sequence of equipment repairs during the repair cycle. For example, the repair cycle structure may include the following repair sequence:

K–T 1 - T 2 - T 3 - TO,

Where T 1 , T 2 And T 3 - respectively, the first, second and third current repairs;

TO- major repairs (only one major repair is included in the repair cycle).

The content of work performed within each of the current repairs is regulated and may differ significantly from others present in the repair cycle. The structure of the repair cycle may include a small ( M) and average ( WITH) repair: for example, T 2 = C; T 1 = T 3 = M.

Similarly, the structure of the maintenance cycle can be presented, establishing the list, quantity and sequence of work on between-repair maintenance (shift inspection, partial inspection, replenishment of lubricant, replacement of lubricant, preventive adjustment, etc.). It is possible to include maintenance work ( THAT) into the structure of the repair cycle, for example:

WHO 1 - T 1 - THAT 2 - T 2 - THAT 3 - T 3 - THAT 4 - TO.

The repair cycle is measured by the operating time of the equipment; downtime during repairs is not included in the cycle. The duration of the repair cycle is determined by the service life of the main mechanisms and parts, the replacement or repair of which can be carried out during complete disassembly of the equipment. Wear of main parts depends on many factors, the main ones being

type of production, on which the intensity of equipment use depends;

physical and mechanical properties of the material being processed, on which the wear rate of equipment and its parts depends;

operating conditions, such as high humidity, dust and gas contamination;

equipment accuracy class, which determines the level of requirements for monitoring the technical condition of equipment;

Repair cycle duration T is determined in machine-hours worked by calculation using empirical dependencies that take into account the influence of many factors, including those listed above:

Where T n- standard repair cycle, hours (for example, for certain metal-cutting machines T n= 16,800 hours);

ß P , ß m , ß at , ß T , ß R- coefficients that take into account, respectively, the type of production, the type of material being processed, operating conditions, accuracy and dimensions of equipment.

The values ​​of the coefficients and the standard duration of the repair cycle are determined on the basis of generalization and analysis of the actual data of the enterprise or are taken from reference data.

Overhaul period T mr And maintenance frequency T That are also expressed by the number of hours worked:

, (104)

, (105)

Where n T And n THAT- respectively, the number of routine repairs and maintenance work per one repair cycle.

The duration of the repair cycle, the period between repairs and the frequency of maintenance can be expressed in years or months if the shift of equipment operation is known. Proper care of equipment during its operation, carrying out organizational and technical measures that extend the service life of parts and components of equipment, contribute to a change in the actual duration of the repair cycle and overhaul periods compared to the standard ones. The service life of wear parts and equipment parts is shorter than the duration of the overhaul period. Therefore, it is advisable to replace them as they wear out during the period between repairs. At the same time, the labor intensity of repairs is reduced, and the volume of work on between-repairs increases.

The labor and material intensity of repair and maintenance of equipment depends on its design features. The more complex the equipment, the larger its size and the higher the processing accuracy, the higher the complexity of its repair and maintenance, the higher the labor and material intensity of this work. Based on the complexity of the repair, the equipment is divided into categories of repair complexity. The complexity of repair work separately for the mechanical and electrical parts of the equipment is determined through the complexity of the repair complexity unit.

Repair complexity category (TO) is the degree of complexity of equipment repair. The category of repair complexity of equipment is determined by the number of units of repair complexity assigned to a given group of equipment by comparing it with the accepted standard - conventional equipment. At domestic mechanical engineering enterprises, the unit of repair complexity of a mechanical part is traditionally taken to be the repair complexity of conventional equipment, the labor intensity of a major overhaul of which is 50 hours, and the unit of repair complexity of its electrical part is 12.5 hours (1/11 of the labor intensity of a major overhaul of a 1K62 screw-cutting lathe, which is assigned the 11th category of repair complexity).

Repair unit (R. e.) is the complexity of the corresponding type of equipment repair of the first category of repair complexity. Labor intensity standards per repair unit are set by type of repair work (washing, checking, inspection, current and major repairs) separately for plumbing, machine tools and other work. The complexity of each type of repair work is determined by multiplying the time standards for this type of work for one repair unit by the number of repair units of the complexity category for repairing the corresponding equipment.

Total labor intensity of repair work (Q) in the planning period is calculated using the formula:

q K , q T And q THAT- labor intensity standards for capital and current repairs, maintenance per repair unit, hours;

n TO , n T , n THAT- number of major and current repairs, maintenance work in the planned period.

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Drawing up a preventive maintenance schedule

Preventative maintenance should be understood as restoring the machine’s performance (accuracy, power and productivity) through rational technical care, replacement and repair of worn parts and assemblies, carried out according to a pre-drawn plan. machine repair part power

Planned preventive maintenance is carried out according to a specific system.

The system of planned preventative maintenance should be understood as a set of organizational and technical measures for the technical care and repair of equipment, carried out according to a pre-drawn plan (schedule) in order to ensure trouble-free operation of the equipment.

The preventive maintenance system provides for preventive inspections and scheduled repairs (major, medium, small) after each unit (machine) has worked for a given number of hours.

The inspection is carried out in order to check the condition of the equipment, eliminate minor faults and identify the scope of preparatory work to be performed during the next scheduled repair.

Minor repairs are a type of planned repairs in which, by replacing or restoring worn parts and adjusting mechanisms, normal operation of the equipment is ensured until the next scheduled repair.

Medium repair is a type of planned repair that involves partial disassembly of equipment, major overhaul of individual components, replacement and restoration of a significant number of worn parts, assembly, adjustment and load testing.

Overhaul is a type of planned repair that involves complete disassembly of equipment, replacement of worn parts and assemblies, repair of basic and other parts and assemblies, assembly, adjustment and testing of equipment under load.

There are three main systems for scheduled preventive maintenance of equipment: post-inspection repairs; standard repairs; periodic repairs.

The PPR system is based on the following standards: duration and structure of the repair cycle; duration of the overhaul period; labor intensity and material consumption standards; maintenance standards; equipment downtime for repairs. They are given in industry directories and instructions for the PPR system.

The structure of the repair cycle for the mechanical, hydraulic and electrical parts of a CNC machine tool represents the sequence of repair work and inspections of CNC machine tools in the period between major repairs or between the commissioning of the machine and the first major overhaul, i.e. the repair cycle consists of a certain number planned repairs.

When operating a machine model 6Р13Ф3 in accordance with the requirements, recommendations and compliance with preventive repair measures, its overhaul cycle (working period until the first major overhaul) is 7.5 years when working in two shifts.

It should be taken into account that the greatest efficiency in using the rate can be ensured by rational alternation and frequency of inspections and repairs, carried out taking into account the operating conditions specific to each individual machine.

Recommended schedule of scheduled repairs for this machine: inspection - after II, 34, 56, 69 months; minor repairs - after 22, 68 months; average repair - after 45 months; major repairs - after 90 months (7.5 years).

When using a system of periodic repairs, the planned nature of the main part of the repair work is ensured due to the fact that repairs are carried out according to an annual schedule, within predetermined periods arising from the established periods between repairs.

However, even when using this system, some of the repair work is unscheduled, since not all repair work can be timed to coincide with periodic repairs. Such work includes: replacement of parts with short service life; performing adjustment and fastening work, the need for which arises more often than periodic repairs, and some other work. Not all of these jobs can be performed on weekends and non-working shifts. Some of them have to be done during work shifts. If there is a lot of such work, the unscheduled equipment downtime they cause can cause serious damage to production.

The number of unscheduled repairs and their volume, other things being equal, directly depend on the size of the applied repair periods.

In general, we can say that the longer the turnaround time, the greater the volume of unscheduled repair work. However, with a reduction in repair periods beyond a certain limit, the total volume of scheduled and unscheduled repair work begins to increase. This is explained by the fact that the decrease in unscheduled repairs and the volume of actual repair work during scheduled repairs, which occurs as a result of a reduction in overhaul periods, is simultaneously accompanied by an increase in the total volume of disassembly and assembly work due to the more frequent implementation of scheduled repairs.

Therefore, the periods between repairs should not be maximum, as is sometimes recommended, and not minimum, but optimal; Moreover, optimal repair periods should be understood as those in which unscheduled repair work cannot cause any significant damage to production, since it is of a nature and volume that allows the bulk of it to be carried out on non-working days and lunch breaks.

Since unscheduled repairs cause the greatest damage in conditions of mass production and less in conditions of serial and individual production, the periods between repairs should be different for different types of production. For equipment operating in mass and large-scale production, the overhaul periods should be shorter, and in serial and individual production - longer.

Below is a table of the duration of between-repair cycles, inter-repair and inter-inspection periods and a table for determining the duration of the repair cycle and inter-repair period.

Com - coefficient taking into account the material being processed (steel: Com = 1; other materials: Com = 0.75);

Kmi is a coefficient that takes into account the material of the tool used (metal: Kmi=1; abrasive: Kmi=0.8);

Kts is a coefficient that takes into account the accuracy class (normal machine accuracy: Kts = 1; increased machine accuracy: Kts = 1.5; high machine accuracy: Kts = 2.0);

Kks is a coefficient that takes into account the mass of the machine (up to 10t: Kks=1; over 10 - up to 100t: Kks=1.35; over 100t: Kks=1.7);

Kv - coefficient taking into account the age of the machine (over 10 years: Kv = 0.9);

Kd - coefficient taking into account the year of manufacture of the equipment (Kd=1).

Repair cycle:

Tpr = 16800 · 1 · 1 · 1 ·1 · 0.9 ·1 = 15120 hours = 7.5 years.

Overhaul period:

Tmp = 15120: 6 = 2520 hours = 1.25 years.

Duration of inter-repair cycles, inter-repair and inter-inspection periods.

1.1 - for equipment operating with metal tools under normal conditions;

1.0 - for equipment operating with abrasive tools.

To measure the labor intensity of repairs in the standard provision of the “Unified Maintenance and Repair System”, the term “repair unit” is used, however, in these units the total volume of planned repairs cannot be expressed, since a repair unit here refers to equipment classified in the first category of repair complexity. This unit, therefore, represents a unit of repair complexity (u.r.s.), which allows one to determine the total repair complexity of equipment, i.e., the sum of repair complexity categories. Using this unit, it is impossible to summarize the volumes of different types of planned repairs. Therefore, the summation of the volumes of planned repairs of different types to determine the total volume of planned repairs is now carried out, expressing them in man-hours. But labor costs in man-hours for scheduled repairs of the same equipment may be different. They depend on the level of organization and technology of repair work at the plant, the quality of equipment operation and care, and a number of other reasons. Under the influence of these reasons, they can undergo significant changes.

Maintenance standards include: time standards for washing, checking geometric accuracy, inspections, small, medium and major repairs of the machine, as well as standards for between-repairs maintenance per worker per shift. The standards do not take into account work related to the transportation of equipment and the construction of its foundation.

Time standards for electrical plumbing work do not take into account the restoration of old winding wires of electric motors and control gear.

The amount of equipment downtime due to malfunction or repair is the most important indicator characterizing the level of organization of equipment repair at the plant and its technical condition. The amount of equipment downtime during unscheduled repairs makes it possible to judge the degree to which planned repairs satisfy the equipment’s need for repair work, i.e., the correspondence of the volume of repairs carried out in a planned manner to the normal volume of repair work for a given equipment.

To analyze equipment downtime due to repairs, it is necessary to keep accurate records of downtime. There are a number of methods for mechanized recording of equipment operation and downtime using appropriate instruments and devices. However, they have not yet received wide enough distribution. The most widespread is the recording of downtime and use of equipment, based on recording by production foremen of downtime of equipment associated with downtime of workers (in simple sheets) and downtime of equipment not related to downtime of workers (in reports on downtime of machines compiled by shifts at each production site ). This accounting method can be quite accurate only when equipment downtime is taken into account not only due to repairs, but for all possible reasons, which makes it possible to draw up a complete balance of equipment operation.

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How to draw up a maintenance schedule for electrical equipment?

How to draw up an annual maintenance schedule for electrical equipment? I will try to answer this question in detail in today’s post.

It's no secret that the main document by which electrical equipment is repaired is the annual schedule of preventive maintenance of electrical equipment, on the basis of which the need for repair personnel, materials, spare parts, and components is determined. It includes each unit subject to major and routine repairs of electrical equipment.

To draw up an annual preventive maintenance schedule (preventive maintenance schedule) for electrical equipment, we will need standards for the frequency of equipment repairs. This data can be found in the manufacturer’s passport data for electrical equipment, if the plant specifically regulates this, or use the reference book “System for Maintenance and Repair of Power Equipment.” I am using the 2008 reference book, so I will continue to refer to this source.

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So. Your household has a certain amount of energy equipment. All this equipment must be included in the maintenance schedule. But first, some general information about what the annual PPR schedule is.

Column 1 indicates the name of the equipment, as a rule, brief and understandable information about the equipment, for example, name and type, power, manufacturer, etc. Column 2 – number according to the scheme (inventory number). I often use numbers from electrical single-line diagrams or process diagrams. Columns 3-5 indicate service life standards between major repairs and current ones. Columns 6-10 indicate the dates of the last major and current repairs. In columns 11-22, each of which corresponds to one month, the symbol indicates the type of planned repair: K - capital, T - current. In columns 23 and 24, respectively, the annual equipment downtime for repairs and the annual working time fund are recorded. Now that we have examined the general provisions about the PPR schedule, let’s look at a specific example. Let's assume that in our electrical facilities, in building 541, we have: 1) a three-phase two-winding oil transformer (T-1 according to the diagram) 6/0.4 kV, 1000 kVA; 2) pump electric motor, asynchronous (designation according to scheme N-1), Рн=125 kW; Step 1. We enter our equipment into the empty PPR schedule form.

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Step 2. At this stage, we determine the resource standards between repairs and downtime. a) For our transformer: open the reference book p. 205 and in the table “Standards for the frequency, duration and labor intensity of repairs of transformers and complete substations” we find a description of the equipment that is suitable for our transformer. For our power of 1000 kVA, we select the values ​​of the frequency of repairs and downtime during major and current repairs, and write them down in our schedule.

b) For an electric motor according to the same scheme - p. 151 Table 7.1 (see figure).

We transfer the found standards in the tables to our PPR schedule

January 2005." href="/text/category/yanvarmz_2005_g_/" rel="bookmark">January 2005, current - January 2008. For the N-1 pump motor, capital - September 2009, current - March 2010. We add this data into a graph.

January 2011." href="/text/category/yanvarmz_2011_g_/" rel="bookmark">January 2011, it is for this year that we draw up a schedule, therefore, in column 8 (January) for the T-1 transformer we enter “ T".

September 2015." href="/text/category/sentyabrmz_2015_g_/" rel="bookmark">September 2015. The current one is carried out 2 times a year (every 6 months) and, according to the latest current repair, we plan for March and September 2011 Important note: if the electrical equipment is newly installed, then all types of repairs, as a rule, “dance” from the date of commissioning of the equipment. Our schedule takes the following form:

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Important note: at some enterprises, power engineers in their annual production schedules, instead of the last two columns of annual downtime and annual capital, indicate only one column - “Labor intensity, man*hour”. This labor intensity is calculated by the number of pieces of equipment and the labor intensity standards for one repair. This scheme is convenient when working with contractors performing repair work. Do not forget that repair dates must be coordinated with the mechanical service and, if necessary, the instrumentation service, as well as with other structural units directly related to the repair and maintenance of related equipment. If you have any questions about drawing up the annual PPR schedule, ask questions, I will try, if possible, to answer them in detail.