Programming the operating mode of household machines and appliances. Repair of household electrical appliances. Heating elements defective

Department "Service of household machines and appliances"

V.V. Gladkevich

V.A. Zaitsev

Technological
service industry systems

Program, methodological guide to the course

design for students of the specialty 060800

"Economics and management in service enterprises"

St. Petersburg

Approved at the meeting of the department "Service of household machines and appliances", protocol No. 7 dated 08.06.2001

Approved by the Methodological Council of the Faculty of Technical Systems Service, protocol No. 11 dated 12.06.2001.

Technological systems of the service sector. Program, methodological guide to course design for students of the specialty 060800 "Economics and management in service enterprises." - St. Petersburg: Publishing House of the IIG "AKTIB", 2001. - 35 p.

Compiled by: Cand. those. Sciences, Assoc. V.V. Gladkevich;

cand. those. Sciences, Assoc. V.A. Zaitsev

Reviewer: Cand. those. sciences, prof. Department "Technical systems of the RKK"

VIKU them. A.F. Mozhaisky E.M. Roslyakov

ÓInformation and publishing group "AKtiB"

Ó St. Petersburg State Institute of Service and Economics
2001

General guidelines

When studying the discipline "Technological systems of the service sector", students, guided by the course program, independently work on textbooks and teaching aids and complete course projects.

It is advisable to make a summary after studying each topic and reinforce the theoretical material with the implementation of a course project.

2. Goals and objectives of the discipline

2.1. Objectives of teaching discipline

The purpose of teaching the discipline is to provide students of the Faculty of Economics, Management and Finance with knowledge in the field of industry production and service, a general understanding of the technical and technological systems of service enterprises, practical skills in the analysis, selection and evaluation of engineering equipment with a feasibility study of parameters, paying attention on the features of the rules and safety measures during operation.

2.2. The tasks of teaching discipline

As a result of studying the discipline, the STUDENT should know:

Characteristics of the habitat and features of the operation of technological and technical systems;

Technique and engineering equipment of industry enterprises;

Types of energy carriers (power supply, water supply, heat supply, gas supply, etc.);

Rules and safety measures during operation.

The STUDENT should be able to:

Focus on the market of machinery and engineering equipment of the industry;

Analyze, select and calculate some elements of engineering equipment of technical and technological systems;

Technically competently operate the equipment.

The STUDENT should be familiar with:

With the prospects for the development of engineering equipment for technological and technical systems of enterprises in the industry.

3. Thematic content of the discipline

Introduction. Scientific and technological progress, factors and main directions of equipment development. Multilevel scheme of goals and objectives in engineering and technology. Waste-free energy and resource-saving technologies.

Topic 1. Technological and technical systems of the industry

Composition of technological and technical systems of the industry. Production types. Types of technological processes. The concept of the production and technological process. Typical groups of technological processes at the enterprises of the industry. Technological processes, their description and general principles of calculation and design. Mathematical description of technological processes.

Topic 2. Operation of machinery and equipment

Basic definitions and concepts of operation. Operational indicators of engineering equipment of enterprises in the industry. Basic concepts of quality. Quantification of manufacturability. The concept of preventive maintenance of equipment.

Topic 3 Reliability of technical systems and engineering equipment

Basic concepts and definitions of reliability. Evaluation of economic indicators of reliability. Evaluation of integral quality indicators. Evaluation of the integral indicator of equipment efficiency. Reliability assessment of engineering equipment and systems according to standard models. The efficiency of the production system. Interrelation of reliability of elements of technical systems and efficiency.

Topic 4. Technological processes of installation of systems and
assembly of engineering equipment

Installation and assembly tasks. Technological processes of installation and assembly. Assembly (disassembly) schemes. Evaluation of the effectiveness of the technological process of installation and assembly. Technological maps of assembly (disassembly). Methods and actions for diagnosing and controlling assembly quality. Diagnosis reliability indicators.

Topic 5. Power supply systems of enterprises

The concept of electrical networks. The concept of the calculation of electrical loads. Selection of electric motors, devices and conductive elements. A simplified method for calculating cable sections. Features of operation and electrical safety engineering.

Topic 6. Ventilation and air conditioning systems

Measures to improve the state of the air environment and the role of ventilation in its improvement. Classification of ventilation systems.

Building aeration. General-exchange ventilation with mechanical stimulation. Air conditioning. Classification of air conditioners and their device. Features of selection and operation.

Topic 7. Water supply and sewerage systems of enterprises

Classification of water supply systems. Water quality requirements and water supply standards. The main schemes of internal water supply. General information about hot water supply and consumption rates.

Classification of sewerage systems. The device of the internal sewerage system. Features of operation.

Topic 8. Heating systems, central, heat and gas supply

The concept of the microclimate and the purpose of heating devices. General information about central heating and gas supply. Water and steam heating. Air heating. Schemes of gas distribution networks of high and low pressure. Features of operation.

Topic 9. Fire extinguishing and fire alarm systems

Classification of fire extinguishing systems. Aerosol and powder fire extinguishing system. Technological process of the security fire extinguishing system. Installation of automatic extinguishing foam. Special fire extinguishing systems. Features of operation.

Topic 10. Modern means of communication and communication systems

Classification and types of modern means of communication and communication. Composition of digital hybrid supersystems. Integrated business systems. Data transmission and document exchange systems with message switching. public commercial networks.

Topic 11. Sewing studios

Approximate production structure of a tailoring studio for individual orders. Technological process in the sewing industry and the equipment used. Features of the technology of wet-heat treatment of garments and the equipment used. A rational choice of equipment for the manufacture of garments for individual orders. Features of operation.

Topic 12

The concept of dry cleaning clothes. The main operations of processing products in the technological sequence of dry cleaning and mechanized laundries. Dry cleaning and laundry equipment. The main units and technological operations performed. Regeneration, drying and recovery systems. Features of operation.

Topic 13

Classification of workshops for the repair of household appliances. Basic technological operations for repair. Maps of the technological process of repairing a single part. Schemes of the technological process of product restoration. Characteristics of the main defects of the repaired products. Calculation of the labor intensity of restoring a part.

course project

In the process of learning, the future economist-manager in the specialty 06.08.00 should be able to analyze the production activities of a service enterprise with a feasibility study of the engineering solutions and technological processes of the industry.

Course design in the discipline "Technological systems of the service sector" prepares students for writing the technological part of a graduation project, and in the future prepares an economist-manager to make decisions that are optimal for a given service enterprise, taking into account modern and promising technologies.

The purpose of course design is:

To teach students to apply theoretical knowledge to solving specific engineering problems using the technology of the service sector;

Deepen and consolidate theoretical knowledge of production technology and service;

Acquire skills in the development of engineering solutions and in their feasibility study in order to improve the quality of public services.

The course design topics correspond to the course program and are linked to the practical requirements of the industry and modern achievements in science and technology. The topics of course projects are the technological processes of service of modern enterprises in the sphere of everyday life and services. The names of the topics of course projects are presented in Appendix 1. The topic of the course project is selected according to the last digit of the student's record book cipher.

The choice of engineering equipment for the designed technological system is carried out by the student independently, using Appendix 2. With the permission of the teacher, it is allowed to complete the course project on the topic proposed by the student, but in terms of the content and volume of the proposed methodological manual. The implementation of not your own version of the course project will entail the implementation of the required version, regardless of quality.

Guidelines for the design of the course project
on the chosen topic in accordance with Appendix 1

The course project consists of an explanatory note and a graphic part.

The settlement and explanatory note should include the following sections:

Title page of the explanatory note.

Assignment for the course project.

2. Modern directions and level of development of technological and technical systems of the industry.

3. Selection and layout of the industry's technological system equipment indoors.

4. Calculation of artificial lighting.

5. Calculation of the power supply of the premises:

5.1. Load distribution by phases.

5.2. Calculation of the cross section of conductors and cables.

6. Calculation of ventilation (conditioning) of the room.

6.1. Calculation of heat and moisture surpluses.

6.2. Determination of the air flow required to remove excess heat and moisture.

6.3. Selection of fan and electric motor.

6.4. Calculation and selection of a heater.

7. Calculation of the reliability of the technological and technical system of the industry.

7.1. Drawing up a functional diagram of the reliability of the technological system.

7.2. Determination of the probability of failure-free operation of the technological system.

7.3. Estimation of optimal parameters of reliable operation.

Conclusion.

References.

Applications.

The main purpose of the title:

Quick definition of the required department of the chapter;

Familiarization with the thematic content and construction of the work in order to better assimilate.

By design, each rubric in the table of contents is an exact copy of the same rubric in the main text. Moreover, full verbal, grammatical and graphic correspondence of headings is required. Page numbers should be placed next to each list of headings.

Rice. 1a. Floor plan and lighting fixtures

P 1 =100 P 2 =100 P 3 =100 P 4 =100W

Fig 1b. Design scheme

5.2. Calculation of the cross section of conductors and cables

1. According to fig. 1a, a calculation scheme is drawn up in Fig. 1b.

2. Assuming that the wires are of the same section along the entire length of the wiring, the load moments are calculated not according to the sections "l", but according to the total lengths "L" from each load to the power supply:

М΄=р 1 L 1 + р 2 L 2 + р 3 L 3 + р 4 L 4 [W m].

where: L 1 =l 1 ; L 2 \u003d l 1 +l 2; L 3 \u003d l 1 + l 2 + l 3; L 4 \u003d l 1 + l 2 + l 3 + l 4,

M΄΄ \u003d P 1 l 1 + P 2 l 2 + P 3 l 3 + P 4 l 4

where: P 1 = p 1 + p 2 + p 3 + p 4; P 2 = p 2 + p 3 + p 4; P 3 \u003d p 3 + p 4; P 4 =p 4 .

Moreover: М΄=М΄΄=M.

1. Permissible voltage loss in volts:

ΔU=ΔU% U/100, V.

According to PES for lighting networks ΔU=±5% of the nominal, for power networks ΔU=±10%.

2. The cross section of the wires must not be less than those calculated by the expression:

where: γ – specific conductivity for copper, γ=54, and for aluminum – γ=32;

U - rated voltage, V, for the lighting (single-phase) network U = U f = 220V, for the power (three-phase) network U = U l = 380V.

5. Current at the head section of the wiring, A:

I 1 \u003d P 1 / U f - for a single-phase line;

I 3 \u003d P 1 / 1.73 U l cos φ o 1 - for a three-phase line,

where: P 1 - power passing through the section O1, W; U f - phase voltage, 220 V; U l - linear voltage, 380V; cos φ o1 is the power factor of section O1.

Fig.4 Series-parallel connection of elements

For a structure with a parallel-serial connection of elements (see Fig. 5), the probability of failure-free operation is calculated by the expression: Р 5-8 = 1-(1-Р 5-6)х(1-Р 7-8)= 1-( 1-P 5 xP 6) x (1-P 7 xP 8).

Fig.5 Parallel-serial connection of elements

The functioning of service systems is ensured by the high-quality and reliable operation of the following subsystems with the probability of failure-free operation Р(t); external electrical networks of the city with Р ne (t); internal electrical networks of the building (premises) with Rwe (t); electric power equipment with P with (t); lighting electrical equipment with P 0 (t); technological equipment (sewing machines, wet-heat treatment equipment, etc.) with Р t (t); equipment of technical service systems (ventilation and air conditioning, fire extinguishing and fire alarm systems, etc.) with R m (t).

For example, the reliability model of a service system with a series-parallel connection of elements can be represented by a block diagram in the form of Fig. 6:

P c (t) P t (t)

P ne (t) P ve (t)

P 0 (t) P m (t)

Rice. 6 Structural diagram of the “reliability model”, taking into account the power supply of technological and technical equipment of the service system

The calculation formula for the probability of failure-free operation of this system will have the following form:

R ss (t) \u003d R ne (t) xR ve (t) xR som (t) \u003d R ne (t) xR ve (t) xx

If the block diagram of the reliability model of the service system includes an urban outdoor water supply system with a probability of failure-free operation Р нв (t) and an internal water supply system of a room with a probability of failure-free operation Р вв (t), then the block diagram will take the form of Fig. 7:

P ne R ve

Rice. 7 Structural diagram of the reliability model, taking into account the power and water supply of technological and technical equipment of the service system with series-parallel connection of elements

If the service system is represented by a parallel-serial connection of elements P s, P t, P 0 and P m, then the block diagram will take the form of Fig. 8:

R ss

Rice. 8

If the probability of non-failure operation of the system exceeds 0.9, i.e. λ with t ≤ 0.1 with accuracy sufficient for practice in case of sudden failures of elements, when the running-in of the equipment is completed, and aging has not yet begun, the exponential distribution law of the probability of failure-free operation is most applicable, i.e.

where is the system failure rate, 1/h; - working time, hours

And

Failure rate:

Mean time between failures (until the first failure), hours: T sr.c =1/λ s at maximum failure rate (a s. max).

If there is a redundancy of elements of the service system by a common substitution with an integer multiplicity and the probability of failure-free operation is below 0.9, then the following relationship is true:

In this case, the failure rate is calculated by the formula:

where is the average failure rate of each of the elements of the subsystems during a given average time t 0 .

For example, with an average probability of non-failure operation of the elements of subsystems P avg. =0.998 we have for t 0 =10 hours of work: λ 0 t 0 =0.002, i.e. λ 0 \u003d \u003d 0.2 × 10 -3 1 / h. Mean time to first failure of the system T cf. \u003d 2T 0 cf., where T 0 cf. - mean time to first failure of a non-redundant system:

T 0 cf. \u003d 1 / λ 0 \u003d 1 / 0.2 10 -3 \u003d 5000 h. Mean time to first failure of a redundant system T cf. \u003d 2T 0 cf. =10000h

Then the failure rate is calculated by the formula:

and the failure rate according to the expression:

When constructing dependence graphs and as a function of time, set the time values with a calculated interval of 15000 hours (1.5 × 10 4 hours).

Execution steps

1. Draw up a functional-structural diagram of the reliability of a technical system that has the above selected mechanisms and devices according to the design and principle of operation of individual devices.

2. Distribute and combine elements into subgroups and groups, taking into account their interaction.

3. Compose calculation expressions for calculating the probabilities of failure-free operation of individual subgroups and the system as a whole.

5. Calculate the mean time between failures.

6. Plot graphical dependencies λ with and as a function of time. The values of λ with and tabulate.

Conclusion

This section completes the course project and should contain the conclusions of the work done.

Here it is necessary to highlight the following:

1. The degree of elaboration of the tasks set during the period of work on the course project.

2. Draw conclusions on the main results obtained.

3. Outline the features of the work in the course of the course project.

4. Give suggestions on possible directions and ways to improve the tasks set to eliminate the shortcomings of the project.

Literature

1. I.L. Kaganov. Course and diploma design. – 3rd edition. - M.: Agropromizdat, 1990 - 351 p.

2. Bulat E.P., Tarabanov V.N. Methodological guide to course design for students in the discipline "Engineering and Technology of the Industry" (special 06.08.00). - St. Petersburg: SPbTIS, 1996.

3. Soloviev V.N., Goncharov A.A. Organization of activity of service enterprises. Methodological guide to course design - St. Petersburg: SPbGISE, 2000.

4. V.V. Gladkevich, V.I. Zaplatinsky. Reliability of household appliances. Tutorial. - St. Petersburg: SPbTIS, 1995.

5. S.F. Privalov. Electrical appliances and devices. Master's Handbook. - St. Petersburg: Lenizdat, 1994. - 511p.

Applications

The appendix provides supporting information that is for reference only.

Applications include the following materials:

Annex 1. Topics of course projects

Appendix 2. Characteristics of the main equipment of service systems. Annex 3. Design of the title page. Appendix 4. Maximum Permissible Concentration (MPC) of harmful substances in the room. Appendix 5. i-d diagram of air. Appendix 6. Specifications of fans. Appendix 7. Electric motors of the AO and A series. Appendix 8. Lines, signs and geometric shapes used in the standards.

Attachment 1

Topics of course projects

No. p / p	Topic name	Note
	Project of a technological (technical) system of a cultural and entertainment center (cinema, game complex, circus, attraction, salon-exhibition, etc.)	The type of object is indicated in the task by the head of the course project.
	Project of a technological (technical) system for a beauty salon (hairdresser, etc.)
	The project of the technological (technical) system of the enterprise "bar-cafe-restaurant" (kitchen, catering department, dining room, etc.)
	The project of the technological (technical) system of the atelier of individual tailoring
	Project of a technological (technical) system of a sports and recreation complex (gym, swimming pool, etc.)
	The project of the technological (technical) system of the hotel (camping, tourist base, etc.)
	Project of a technological (technical) system for dry cleaning of clothes (micro dry cleaning, etc.).
	The project of the technological (technical) system of the bath and laundry plant (pool, sauna, etc.).
	The project of the technological (technical) system of the office premises of the industry.
	The project of the technological (technical) system of the service workshop (manufacturing and repair of metal products, after-sales service of household appliances, etc.)

Annex 2

Characteristics of the main equipment and technology of the service sector
(accepted conditionally)

No. p / p	Equipment name	Dimensions, L In mm	Consumed power, kWt	Quantity warm- emissions, kJ/h	The amount of moisture leniya, kg/h	Probability of failure-free operation.

	Household Machines and Appliances Electric Oven	850 600				0,95
	Electric meat grinder	520 200	1,5			0,92
	Food processor	460 320	0,8			0,93
	Dishwasher	850 450	2,1		0,5	0,91
	Electric water heater	1350 650	4,0			0,94
	Electric grill, oven	420 180	2,0			0,93
	Electric heaters, convectors	1000 100	2,5			0,92
	Air cleaner, climate control	400 200	0,6			0,96
	A vacuum cleaner	540 190	0,8			0,95
	Refrigerator compression	600 600	0,2			0,94
11.	Microwave	510 360	0,8			0,98
12.	Washing machine household	600 600	3,0			0,93
	mobile air conditioner	850 440	2,0			0,95
14.	oil heater	860 120	2,4			0,98
15.	Electric heater fan	300 175	2,0			0,94
16.	electric grinder	240 140	0,22			0,95
17.	Hand dryer	230 200	0,1			0,93
18.	Electrical appliances for welding polyethylene film	210 140	0,22			0,94
19.	Laundry dryer	600 450	2,5		0,6	0,93
	ironing machine	900 400	1,3		0,3	0,95
	Equipment of service enterprises Pumping station	500 210	0,8			0,92
	Compressor plant	2750 610	1,7			0,92
	Vacuum plant	750 490	2,0			0,93
	steam generator	960 700			4,0	0,91
	steam press	1070 1300			6,0	0,92
	Steam mannequin	1241 690			8,0	0,93

Table continuation

Laboratory work No. 8 "Procedure for organizing service maintenance of electrical machines"

The purpose of the work: To study the procedure for organizing the maintenance of electrical machines.

Working process:

Service center -- an organization engaged in the provision of service support and maintenance of machinery, equipment and other products. The activities of service centers include pre-sales, warranty and after-sales repairs.

Servicing a car in a car dealership guarantees protection from unforeseen situations for the owner of the vehicle, as well as the implementation of certain measures to keep the car in working order. To exclude or at least prevent significant breakdowns, it is necessary to periodically contact the service center for diagnostics. As a result, the timely elimination of minor breakdowns and damage. Typically, car maintenance includes checking primary assemblies and assemblies, changing oil and antifreeze, and if problems are found, replacing brake pads, belts, and spark plugs.

One of the decisive factors in a consumer's choice of product is how much support the supplier promises after the sale of that product. This factor is especially important when buying electrical household appliances, appliances and electronics, building materials, cars, etc., that is, in those areas where a breakdown or factory defect means that the product cannot be used for its intended purpose or prevents it.

When buying a product, the warranty period for the product and its service life are established. During the warranty period, the buyer is entitled to free repair of the goods or (in special cases -- see below) to replace it. After the expiration of the warranty period, the repair of equipment is carried out at the expense of the consumer. After the expiration of the service life of the product, the manufacturer has the right to refuse the consumer to repair this product.

The activities of service centers are regulated at the legislative level, in accordance with the laws of the country in which the service is provided. According to the Law on Consumer Rights of the Russian Federation, information about the product must contain the warranty period of the product, if it is established.

“Consumer rights in case of defects in the product”:

The consumer, in case of detection of defects in the goods, if they were not specified by the seller, at his choice has the right to:

demand a replacement for a product of the same brand (the same model and (or) article);

demand a replacement for the same product of a different brand (model, article) with a corresponding recalculation of the purchase price;

demand a commensurate reduction in the purchase price;

demand immediate gratuitous elimination of product defects or reimbursement of expenses for their correction by the consumer or a third party;

refuse to fulfill the contract of sale and demand the return of the amount paid for the goods. At the request of the seller and at his expense, the consumer must return the goods with defects.

In this case, the consumer has the right to demand also full compensation for losses caused to him as a result of the sale of goods of inadequate quality. Losses are reimbursed within the time limits established by this Law to meet the relevant requirements of the consumer.

The new version of the Law mentions the period during which the consumer has the right to make a claim for the replacement of goods and for a refund if defects are found in the goods -- 15 days. If the color, size, shape of the product does not suit the consumer, then the product cannot be exchanged! After the expiration of the period established in 15 days, these requirements are subject to satisfaction in one of the following cases:

discovery of a significant defect of the goods;

violation of the deadlines established by this Law for the elimination of defects in goods;

if, in case of repeated failure, the customer was unable to use his product for more than 30 days due to being under repair

Diagnostics of the device is the most important and difficult task:

1 Determine which node (block) is not working?

2 Reason for failure?

3 Is it possible to restore a node (block)?

4 Cost of a new one?

5 Agree on the cost with the customer?

If the master does not have confidence in the operation of other units, it is often necessary to completely repair and check the device and then agree on the cost.

In cases where the customer is not satisfied with the cost of repair, the master dismantles the installed parts and the device is returned to the customer who pays only for diagnostics.

The company is based on experienced specialists who stood at the origins of our workshop. The close-knit team combines the bold ideas of young professionals and the experience of professionals. This allows you to solve almost any problem for the repair of household appliances.

When working, we always try to show a flexible approach to each client and his problem.

Repair of large household appliances

Another important direction of our workshop is the service of large household appliances - repair and installation of washing machines, repair of large TVs. Also, our masters carry out repair and maintenance of domestic refrigerators.

Our masters for the repair of large household appliances go to repair washing machines and refrigerators in all areas of Moscow.

Types of repair of household appliances

Depending on the complexity, the repair of household appliances can be divided into three categories - small, medium and complex:

minor - repairs that do not require complete disassembly of the device: replacement of an electric cord, which is typical for irons and electric drills, replacement of fuses and indicator lights, replacement of handles and broken nozzles, lubrication and cleaning of household appliances.
medium - repair requiring complete disassembly of the device: replacement of the switch, motor brushes, burnt capacitances and resistances, all types of gears.
complex - replacement of an electric motor, electric heater, all types of bearings, transformers, electronic control boards, replacement and repair of magnetrons in microwave ovens (MW).

Repair of household appliances

The masters of our service center carry out post-warranty repairs of small household appliances. All work performed and parts replaced are warranted.

With the constant use of household appliances, various malfunctions may occur. In this case, you must contact the workshop, as self-repair can lead to injury and electric shock. Only an experienced craftsman can determine the nature of the malfunction of a household appliance and eliminate it.

Malfunctions in household appliances are electrical and mechanical in nature. Electrical malfunctions of household appliances include such malfunctions as the device not turning on - (the indicator lamp does not light), the heating elements do not work (at the electric kettle, steamer, toaster, iron, hair dryer, coffee machine), the electric motor does not rotate (vacuum cleaner, mixer, coffee grinder, drills).

Mechanical malfunctions of household appliances include: damage to gears in meat grinders, mixers, sewing machines, failure of attachments in blenders and food processors, failure of mechanical knives for chopping products that are used in small household appliances.

outdoor clocks with home visits, Hermle, Howard Miller, Kieninger, Polaris, Du Chateau and other repair manufacturers
soviet watch repair
watches made in Russia repair
watches made in Germany repair
watch made in France repair
watch made in english repair
watch Howard Miller repair
clock Franz Hermle (Xermle) repair
Sinclar Harding H1 watch repair
cuckoo clock mechanical and quartz repair
manufacture of pendelfedor, pendulum hangers
watch glass manufacturing
watch key making
manufacture of clock weights.
restoration of buildings
microwave oven repair
microwave oven repair
Manufacturing of microwave filters (mica)
ironing systems repair
repair of steam generators repair
iron repair repair
meat grinder repair
vacuum cleaner repair
washing vacuum cleaners repair
repair robot vacuum cleaner repair
hair clipper repair
multicooker repair
sewing machine repair Seagull repair
sewing machines Podolsk repair
sewing machine belt Radom
repair of sewing machines Mikron
Jaguar sewing machine repair
sewing machines Mini Yagua repair
sewing machines Veritas repair
Janome sewing machine repair
sewing machine repair Singer repair
sewing machines Pfaff repair

Performed in the interval between scheduled and unscheduled repairs of production equipment. The goal is to guarantee reliable and continuous operation. Timely maintenance and competent operation significantly reduce repair costs and forced downtime.

Maintenance Tasks

It is safe to say that maintenance is a critical preventive action that is essential to ensure the continued operation of production equipment and machinery between scheduled maintenance operations. It involves the care and exercise of control over the operation of machines, their maintenance in good working order, scheduled maintenance, cleaning, flushing, adjusting, purging and other repairs of equipment.

Certain types of maintenance can be carried out directly on the operating equipment using breaks and days off. If there are appropriate permits in the operating instructions for mechanisms and equipment, it is possible to briefly disconnect them from the power grid until they stop completely. In such cases, some downtime is allowed, but so that production and

Regulatory documents

GOSTs regulating the use of maintenance systems and equipment repair are 18322-78 "System for maintenance and repair of equipment. Terms and definitions" and 28.001-83 "System for maintenance and repair of equipment. Basic provisions". It is these standards that determine the classification and types of maintenance of electrical equipment.

Classification of types of maintenance

assessment of wear of rubbing parts;
tightening of fasteners and tension elements;
check of protective devices and clips;
determination of noise and vibration;
regulation of the supply of coolants and oils, etc.

Some items are also included in the list of maintenance for press-forging, woodworking, foundry equipment, with the exception of specific features of operation and device.

Maintenance and repair system

The main task of automated systems for which various types of maintenance are carried out is to reduce the costs of this budget item of the enterprise and significantly increase the reliability class of machines and mechanisms, which helps to reduce the cost of production and, accordingly, increase income.

In the case of a repair, the task changes, since it is necessary to minimize not only losses, but also the frequency of the work itself (regardless of the type and volume). The ideal scheme that enterprises strive for is a complete rejection of which inevitably leads to unscheduled production shutdowns.

In addition, operation and maintenance, in particular repair work, is carried out under conditions of some uncertainty. Even the monitoring of the wear of industrial equipment and many years of experience cannot determine the specific volume and indicate the range of new spare parts for equipment. But the conveyor system involves the exact distribution of the necessary parts that may be required from the warehouse for a specific order.

What is a maintenance and repair system

The maintenance and repair system is a complex of interconnected specialists, technical devices, reporting and fixing the results of documentation. All of them are necessary to maintain the proper condition of industrial equipment, as defined by GOSTs.

All enterprises in the country use a unified concept of maintaining working machines and mechanisms in a state of uninterrupted performance, part of which is the use of a legally approved system of preventive maintenance (PPR).

This system is a full-fledged set of organizational and technical actions carried out as planned, aimed at monitoring and ensuring the working condition of the machines and mechanisms available on the balance sheet of the enterprise. Such a system is used during the entire period of operation of the equipment, subject to the regime and operating conditions specified by the manufacturer. Exact compliance with all requirements, recommendations and operating instructions is mandatory.

The system of scheduled preventive maintenance is based on the implementation of scheduled periodic inspections, control of the condition of the main equipment and is in the nature of a preventive measure. Thus, a set of measures that guarantee the maintenance of excellent performance of machines and mechanisms is carried out according to the developed monthly and annual schedules. The latter are compiled with the expectation of the inadmissibility and prevention of unexpected failure of industrial equipment, that is, in the expectation of reducing additional costs.

Maintenance of the maintenance and repair system

The introduction of a system of preventive maintenance in production is ensured by:

sufficient material and technical base and maintenance of a certain frequency of repair work, deadlines;
the full scope of the performed list of maintenance operations that guarantee the uninterrupted operation of machinery and equipment;
the shortest possible period of stay of the failed equipment in repair (especially overhaul).

Implementation of works

Depending on the category and technological importance of the equipment, as well as the stability of the processes and the safety of workers, certain types of repair work can be carried out as a repair due to a faulty technical condition, a regulated (scheduled) repair, a repair by the worked out time, or a combination of them.

Repair of industrial equipment can be carried out by the owning enterprises that directly use it, as well as by specialized teams of manufacturing plants or repair enterprises. The priorities of these organizational schemes for each plant are arranged depending on the availability of their own reserves, equipment, qualifications of maintenance personnel and financial solvency. But each industrial enterprise may, at its own discretion, give preference to any method and form of PPR that best suits the main areas of production.

Maintenance terms

The types and terms of maintenance are calculated in days or months, and this depends on the complexity and type of industrial equipment. So, for example, calculations for (diesel locomotives, electric locomotives, etc.) are made according to the average values of overhaul runs.

The frequency, types and terms of maintenance are calculated according to the calendar time of operation and take into account the technical conditions of manufacturers.

Thus, as a result of a small analysis of the essence, classification, types of maintenance of industrial, production and technological equipment, we can conclude that it is necessary, systematic and mandatory strict control. It is the combination of these components that will allow enterprises to achieve uninterrupted operation of machines and mechanisms, which, in turn, contributes to budget savings, increased labor productivity and additional profit.

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Lab No. 1 « Roasters, grills, shish kebabs»

construction repair maintenance household

The purpose of the work: To study the design and principle of operation of roasters, grills, kebabs.

Working process:

Roster- household electrical appliance, which is a compact oven.

Some models can combine the functions of a toaster, air grill, microwave oven. In the roaster you can cook hot toasts and sandwiches, meat, fish, bake bread or pies. By execution it can be horizontal and vertical. In vertical models of roasters, thanks to special devices, you can cook grilled chicken, kebabs and various types of meat for shawarma. The roaster is suitable for small kitchens, as well as for families who are forced to rent housing. Due to its compact size, it can be taken to the country, where it will quickly help to prepare food. When choosing a roaster, it is required, first of all, to determine the volume and dimensions of this electrical appliance, as well as the necessary set of functions.

Device: Usually, the roaster has two heating elements, in most models - quartz: top and bottom, cooking mode dishes determined by their combination. The cooking temperature is regulated by a thermostat, from 60 (languishing, warming up) to 240-280 (baking) degrees C. Cooking time helps to control the timer: its value can be set from 15 minutes in simple models, up to 100-120 - in multifunctional ones. Usually, after the set time has elapsed, the device will automatically turn off and an audible signal will sound.

Grill - installation (portable or stationary) for cooking on coals, heat. The grill function can be built into a gas stove, microwave oven. There are several varieties of grills; most of them fall into one of three categories: gas, electric and charcoal. There is a lot of discussion about using coal or gas as a cooking method. Electric grills have also recently become popular. There are two main types of modern charcoal grills: with a lid and without a lid. Unlike analogues without a lid, grills with a lid are more multifunctional devices. Thanks to the closed lid, three cooking methods can be used in the grill: direct, indirect and 50/50.

barbecue . The heating elements are regulated by a step switch, providing separate regulation, which saves energy. Structurally, it can be: horizontal and vertical. vertical made in the form cylinder and is equipped with a minimum of five stainless steel skewers. In the upper part of such a device there is a flame chamber, in the lower part there is a drive for rotating skewers. At the bottom there is also a special bowl where fat and juice from meat flows. The strong casing promotes uniform heating of meat and protects from a heat. The principle of operation of the horizontal is identical.

Lab No. 2 "Microwave - ovens, microwaves"

The purpose of the work: To study the design and principle of operation of the microwave ovens, microwaves. Working process

Microwave oven or microwave oven (obsolete emphasis microwave; popular name microwave oven) is an electrical appliance that uses the phenomenon of heating water-containing substances with electromagnetic radiation of the decimeter range (usually with a frequency of 2450 MHz) and is designed for quick cooking, heating or defrosting food, at home or on production.

In industry, these ovens are used for drying, thawing, melting plastics, heating adhesives, firing ceramics, etc. In some industrial ovens, the radiation frequency can change (the so-called English variable frequency microwave, VFM).

Unlike classical ovens (for example, an oven or a Russian oven), food is heated in a microwave oven not only from the surface of the heated body, but also through its volume containing polar molecules (for example, water), since radio waves of a given frequency penetrate and are absorbed by food at a depth of approximately 2.5 cm. This reduces the heating time of food.

How it works: The heating in the furnace is based on the principle of the so-called "dipole shift". Molecular dipole shift under the action of an electric field occurs in materials containing polar molecules. The energy of electromagnetic field oscillations leads to a constant shift of the molecules, lining them up according to the field lines of force, which is called the dipole moment. And since the field is variable, the molecules periodically change direction. When moving, the molecules “swing”, collide, hit each other, transferring energy to neighboring molecules in this material. Since the temperature is directly proportional to the average kinetic energy of the movement of atoms or molecules in the material, this mixing of molecules, by definition, increases the temperature of the material. Thus, the dipole shift is a mechanism for converting the energy of electromagnetic radiation into thermal energy of the material.

Heating in a microwave oven as a result of a dipole shift under the action of an alternating electric field depends on the characteristics of the molecules and the intermolecular interaction in the medium. For better heating, the frequency of the alternating electric field must be set in such a way that the molecules have time to completely rearrange themselves in a half-cycle. Since water is contained in almost all products, the frequency of the microwave emitter of a microwave oven was chosen for the best heating of water molecules in a liquid state, while ice, fat and sugar heat up much worse.

There is a common misconception that a microwave oven heats food from the inside out. In fact, microwaves go from outside to inside, linger in the outer layers of food, therefore heating a uniformly moist product occurs approximately in the same way as in an oven (to make sure of this, it is enough to heat boiled potatoes “in uniform”, where a thin peel protects enough dry product). The misconception is caused by the fact that microwaves do not affect dry, non-conductive materials that are usually found on the surface of products, and therefore their heating in some cases begins deeper than with other heating methods (bread products, for example, are heated precisely “from the inside”, and for this reason - bread and rolls have a dried crust on the outside, and most of the moisture is concentrated inside).

The main components of a magnetron microwave oven:

a metal chamber with a metallized door (in which high-frequency radiation is concentrated, for example, 2450 MHz), where the heated products are placed;

transformer -- magnetron high-voltage power supply;

control and switching circuits;

direct microwave emitter -- magnetron;

waveguide to transfer radiation from the magnetron to the chamber;

auxiliary elements:

· turntable -- necessary for uniform heating of the product from all sides;

Schemes and circuits that provide control (timer) and safety (blocking modes) of the device;

a fan that cools the magnetron and ventilates the chamber.

Lab No. 3 « FROM washing machines»

Purpose of work: To study the design and principle of operation of washing machines .

Working process:

Washing machine-- installation for washing textiles (clothes, underwear and bed linen, bags and other things). An activator-type machine is a washing machine with an activator - a rotating shaft with blades or a disk that provides mixing during washing.

A feature of this type of washing machines is low foaming, so hand washing powders are also suitable for use in activator type machines.

The basis of the design of the activator-type washing machine is a container made of stainless steel or plastic. The top part (for loading of linen) - a removable or folding cover. At the bottom or at the bottom of one of the walls is activator- a plastic flat circle or a shaft with protrusions - blades. The axis of the activator comes out of the tank and is driven by an electric motor.

The activator machines of the Soviet period, as a rule, had a vertical tank made of aluminum or stainless steel with a capacity of up to 30 liters, dimensions up to about 400x400x600 (height) mm, with a bottom in the shape of a semicircle. On one of the flat walls along the axis of the semicircle of the bottom, there was an activator (most often made of bakelite) with a diameter of about 200 mm, driven through a belt drive by a capacitor electric motor located under the tank. The control included a mechanical time relay for 15 minutes (with a specified accuracy of up to 1 minute), automatically turning on the electric motor alternately in different directions through pauses. Also (on later models) the power of the engine could be separately regulated (2 or 3 “modes” of washing). and the pressure of the upper roller to the lower one was regulated by a screw located on top). After washing (or rinsing), the laundry was fed between the spin rollers, when the handle was turned, the water flowed into the tank, and the wrung out laundry came out of the rollers at the back of the machine. Drainage of water, as a rule, was manual (the end of the drain hose was fixed at the top of the tank so as not to use a valve). Most of the volume of the machine is occupied by a tank. The tank prevents the uncontrolled spreading of water or cleaning solution during the operation of the machine. Water is supplied to the tank through the filling hole and is pumped out of the tank using a pump. The tank is fixed in the body of the machine with the help of springs and shock absorbers. A drum rotates inside the tank on bearings. Washing is provided by the rotation of the drum and the mutual impact of the loaded things. Spinning is done, also during rotation, by reducing the pressure and sticking things to the porous walls. The axis of the drum is most often horizontal. Since the drum is usually loaded unevenly, strong vibration occurs when it is rotated at high speed. Therefore, the tank with the drum is not fixed inside the machine rigidly, but with the help of a spring suspension. An electric motor is also fixed on the same suspension. The motor rotates the drum either directly or through a belt drive. The side surface of the drum contains a large number of holes for free inflow and outflow of water and ribs to increase the washing intensity. The drums of front-loading machines are axisymmetric, so they have less vibration during the spin cycle. The drums of top-loading machines in the door area are heavier than in other places, many manufacturers do not balance this difference in weight, which is why they have increased vibration during the spin cycle, which leads to premature wear of the drum bearings. In machines with vertical loading without a door closer to the hatch, you have to bring the drum to the hatch by rotating it with your hands, while due to the sharp edges of the holes on the drum, some manufacturers scratch the pads of a person’s fingers like a grater.

Lab No. 4 "Dishwashers"

Purpose of work: To study the design and principle of operation of dishwashers.

Working process:

Dishwasher -- electromechanical installation for automatic washing utensils. It is used both in catering establishments and at home. The dishwasher is connected to electricity plumbing And sewerage. Principle of operation: Training . Dishes are placed in baskets and trays designed for different types of dishes. The washing program is selected. It is loaded into special containers (powdered or tableted) detergent, or a concentrated washing liquid designed specifically for dishwashers.

Soak . As with hand washing, soaking is good for removing dried-on or burnt-on food fragments. Dishes are sprayed with cold water with little or no detergent and left for a while. Subsequently, when washing, soaked residues are removed much easier.

Washing. The process proceeds as follows: water of the required temperature (depending on the selected washing program) with detergent under pressure is sprayed in thin streams by rotating sprayers onto the dishes both from below and (depending on the model) and from above, washing off food residues and grease.

Rinsing. At the end of the washing procedure, there are several rinsing cycles with clean water with the addition of rinse aid, thanks to which, after drying, there are no traces of dried water drops on the dishes.

Drying. Then, if the machine has a drying function, the dishes are dried. This happens either with the help of a stream of hot air (less common), or by the method of moisture condensation. The last method is implemented as follows. During the last rinse of the dishes, the water (and, as a result, the dishes themselves) is heated. Then the water is removed, and the cooling walls of the machine condense on their inner surfaces the moisture evaporating from the hot dishes. The latter flows down the walls into a common drain.

Advantages: Since a person does not touch the dishes during washing, very strong detergents can be used for them, which are dangerous for hand washing. skin.

For the same reason, it is possible to wash and rinse dishes at high water temperatures (? 55--65 °C)

Water consumption is lower compared to manual washing (9 -- 20 liters vs 60 liters for 12 sets utensils). Savings are achieved through the repeated use of the same water at each stage of washing.

Hot water supply is not required.

Does not require a wide range of detergents and abrasive funds, sponges, brushes, etc. Sufficient special salt for water softener and one type of detergent.

The role of a person in washing dishes is reduced to loading dirty dishes into the machine and unloading clean ones. The process itself does not require participation or supervision and can occur at any time.

disadvantages : Impossible to wash some types of dishes:

non-heat-resistant plastic items; plastic items can only be washed in an industrial dishwasher

wooden boards;

pewter or copper items; This type of dishes can only be washed in industrial dishwashers.

aluminum dishes; when using a special detergent for aluminum utensils in industrial machines

crystal dishes with impurities lead; industrial machines (glass washers) use a rinsing temperature of 65 degrees Celsius, so they are designed for washing glasses, wine glasses and thin glassware

rusty cutlery become;

cutlery with wooden, porcelain, horny, or mother-of-pearl handles;

antique dishes, the coating of which is not heat resistant;

glued dishes.

Lab No. 5 "Sewing machines"

Purpose of work: To study the design and principle of operation of sewing machines.

Working process:

Sewing machine (at home sewing machine) sewing machine) -- technical device for joining and finishing materials method sewing. Sewing machines are used in the sewing, knitwear, footwear and other light industries, as well as in everyday life.

Household sewing machines:

Lockstitch sewing machines

Mechanical and electromechanical

In mechanical sewing machines per movement needles and the movement of the fabric conveyor correspond to special-shaped gears, levers, wheels, copiers and similar mechanics. Machines with mechanical control, due to technological features, can perform a limited number of lines of a relatively simple form. Mechanical machines are driven by the rotation of the flywheel handle or have a foot drive. The handwheel of the electromechanical machine rotates the electric motor, and the sewing speed is controlled by pressing the pedal. There are models that allow you to sew without a pedal (they have a start / stop button and a sewing speed controller).

Machines with microprocessor control (computer machines)

In machines with microprocessor control, the movement of fabric and needle is controlled by a microprocessor. This control principle reduces the restrictions on the complexity of lines and their number. Everything is determined by the amount of memory and the program that the manufacturer has put into this or that model. Only computer controlled machines can perform loops eyelet and intricate decorative stitching.

Embroidery machines

When working on an embroidery machine, the fabric is fixed in the hoop. The hoop drive mechanism receives commands from the computer to move the fabric in accordance with the program -- "machine embroidery design". When all pieces of one color have been embroidered, the machine will pause and wait for the next color to be threaded.

Sewing and embroidery machines

Machines of this class are machines with microprocessor control to which you can connect an embroidery unit and use the machine as an embroidery machine.

Chain stitch sewing machines

Overlocks

Cover stitch machines

Coverlocks

Cover stitch machine combined with overlock

Hemming machines

Machines for blind stitching with chain stitches from the inside out

Lab No. 6 "The procedure for organizing the repair of electrical machines"

The purpose of the work: To study the procedure for organizing the repair of electrical machines.

Working process:

The planning of repairs of electric motors is carried out in accordance with the requirements of the Rules for the Technical Operation of Power Plants and Networks (PTE) according to the system of preventive maintenance (PPR). Scheduled preventive maintenance includes a set of measures: maintenance and supervision during operation; periodic current and major repairs; carrying out preventive tests in accordance with the requirements of the "Electrical Equipment Testing Standards". The frequency and timing of the repair of electric motors are linked to the repair of the driven units. This helps to reduce labor costs for the alignment of the unit with the engine, preparation of the workplace by operational personnel, etc. The frequency of repairs is set by a schedule approved by the chief engineer of the enterprise. When planning the timing of major and current repairs, the technical condition of electric motors, determined during operation (condition of bearings, heating of active parts, etc.), is taken into account. Annual repair schedules are drawn up by the electrical department of the enterprise operating the electric motor and agreed with the contractor performing the repair of electric motors. In accordance with the repair schedule, preparatory work is being carried out, which includes: drawing up a work schedule indicating a list of devices necessary for repairing electric motors and the timing of their manufacture or delivery to the repair site; preparation of necessary materials and spare parts; preparation of fire fighting and safety measures; development and coordination with adjacent workshops of the project for the organization of special works. These works are carried out by the personnel of the operating and contracting organizations. Before the electric motors are taken out for repair, all of the above preparatory work must be completed, the repair personnel must be staffed into teams, familiarized with the scope of the work to be done and the design features of the electric motors. Before starting work, the repair manager should familiarize himself with the reporting documentation on the repairs previously performed on these electric motors, paying special attention to the results of the previous repair, to the time spent by the bearings after their replacement and relubrication, to the value of the air gaps and clearances in the bearings, to the test results . Notes on the operation of electric motors (overheating of the winding, active steel, vibration state, bearing temperature) should also be taken into account.

Organization of workplaces for repair of engines.

The most progressive form of repair maintenance of electric motors is a centralized repair in the conditions of workshops, industrial repair enterprises (PRP), equipped with the necessary equipment and tooling to perform all labor-intensive disassembly and assembly and repair operations. Any type of typical repair, for which it is necessary to disconnect the electric motor from the foundation and the unit, it is advisable to carry out in a special workshop. Appropriate vehicles must be used to transport the electric motors to the workshop, and the workshop's hoists must ensure that they are unloaded. To perform any type of repair using progressive methods that ensure high labor productivity and quality of repairs, the workshop must be equipped with power distribution systems (compressed air, water supply, power supply at various voltages) and include: a chamber for pneumohydraulic cleaning of electric motors, an installation for washing parts, and a drying chamber, slipways for disassembling electric motors with a vertical shaft, tilters for stators, supports for stators, supports for installing and turning rotors, a machine for balancing rotors, a machine for making slot wedges, drilling and sharpening machines, a set of pullers (hydraulic and screw) , a set of devices for extracting sections of the stator windings of electric motors, racks for placing units and parts during disassembly of electric motors and workbenches for repairing units and parts of electric motors. When performing the repair of electric motors in the workshop, in addition to the above equipment, it should include: a chamber for annealing loose windings, an installation for extracting loose windings, winding machines, an impregnating bath and an installation for pouring plain bearings. It is advisable to manufacture backup coils for stator windings of high-voltage electric motors with mica and other insulations at large bases with compounding equipment, which helps to ensure high quality and increase the service life. In the absence of workshops for centralized repair of electric motors, repair sites can be organized. The “repair site” means a free area intended for transshipment operations and placement of assembly units and parts of equipment, repair fixtures and equipment during overhaul, as well as for performing repair operations that, according to the technology, must be carried out near the equipment being repaired. Repair sites must be equipped with power wiring and located in the area of the lifting equipment. Power wiring means wiring of oxygen, acetylene, compressed air with a pressure of (4--6) 10® Pa and technical water with a pressure of 4X XYu5 Pa, as well as a stationary power supply network with a voltage of 380/220 V to ensure electric welding, connecting an electric tool through a frequency converter with a voltage of 36 V (220 Hz) and portable lamps through a 220/12 V transformer. The repair site should have general and local electric lighting.

Lab No. 7 "The procedure for organizing the repair of heating appliances"

Purpose of work: To study the procedure for organizing the repair of heating appliances.

Working process:

Mounting engineering systems in residential buildings can be divided into three points. The first of them is the laying of sewer outlets, water inlets, the supply of gas supply pipes and heating systems. Construction of a boiler house and thermal units. Testing of installed devices. The second stage is the installation of heating devices, pipe connection heating systems , as well as hot and cold water supply and sewerage systems with their subsequent testing. The final stage is the installation of sanitary appliances in an apartment or a country house with their subsequent testing. At the first stage, work is carried out in the basement of the house and in special rooms, for example, boiler rooms, as well as in an open area. Such work is not carried out in a strict sequence, which is not indicated in the repair flow chart. Only the initial, final, and some key intermediate repair points are important here. The other two stages are carried out directly on the renovated floors of the building. The order of these works requires strict adherence to the instructions. After installation of engineering and plumbing communications, they are checked. In this verification, care must be taken to ensure that the final system complies with the approved design and specifications. Compliance with the slopes of sewer pipes and the strength of their fastening is checked. It is necessary to make sure that there are no leaks from sanitary appliances. Before performing work, the assembly team led by the foreman must study the technical documentation at the repair facility, such as estimates, work flow charts, construction drawings, and a project. The foreman needs to explain to the workers the working conditions and safety precautions at the facility. Prior to the start of installation work, the following certain actions are performed. For basements below the zero mark, ceilings, underground channels and partitions are arranged; punches for laying pipelines; mounting openings in walls and ceilings are prepared, brackets are installed for mounting pipelines; prepared and painted places for the installation of heating devices; the base under the floor is prepared; made foundations for the installation of industrial equipment; the premises are cleared of construction debris. In rooms located above the zero mark, all interfloor ceilings and partitions must be arranged, grooves and furrows for laying pipes should be prepared; technological openings were made for supplying equipment and materials to the work site; brackets for fixing equipment are fixed; window sills were installed and preparations were made for clean floors; the necessary markings are applied with paint; prepared niches for radiators; glazing of premises and connection of lighting systems; all rooms are cleared of construction debris. In the bathrooms and in the kitchen, before laying pipelines, the necessary partitions are installed, walls and ceilings are plastered. Scraps are being prepared for laying pipes. Before installing plumbing fixtures, a complex of waterproofing works is carried out, floors are prepared and tiles are laid on the walls, before installing water intake fittings and fittings, the final painting of ceilings and walls is carried out. The sequence of work throughout the entire complex of their implementation is regulated on the basis of a project for a construction site. Compliance with deadlines is especially important when linking with other related works that are performed at this facility. At the same time, the basic requirements are met: brackets are installed before finishing work; sanitary appliances are installed before painting the premises, and water fittings after painting; hydraulic tests of systems are carried out before finishing work. The organization of labor during installation is provided water heating systems with upper wiring in residential and public buildings during the reconstruction of central heating systems in them. Prior to the actual installation in the work area, the following work must be performed: the attic room must be cleared of foreign objects and debris; provided free access to the place of work and proper lighting of workplaces in accordance with the regulations. The main pipelines must be laid in a strictly straight line; a device must be provided for removing air plugs from them. The slopes of the laid pipes must comply with the project, and in the absence of instructions in the project, have a value of at least 0.002. Main pipelines in places of passage through building structures must be placed in sleeves. The sleeves must have a diameter 50 mm larger than the pipe diameter. Connection of pipes in the thickness of building structures or in areas placed in sleeves is not allowed. Welded joints should be located at a distance of at least 500 mm from supports and hangers. Branches to the main pipeline must be connected, if possible, at a right angle.

Lab No. 8 "The procedure for organizing service maintenance electrical machines"

The purpose of the work: To study the procedure for organizing the maintenance of electrical machines.

Working process:

Service center -- organization providing services for service support and maintenance of machinery, equipment and other products. The activities of service centers include pre-sales, warranty and after-sales repairs.

One of the decisive factors in choosing product consumer is what support it promises the supplier after the sale of this product. This factor is especially important when buying electrical household appliances, machinery and electronics, building materials, cars, etc., that is, in those areas where a breakdown or manufacturing defects means the impossibility of using the product for its intended purpose or prevents it.

When buying a product, a period is set guarantees on the product and its service life. During the warranty period, the buyer is entitled to free repair of the goods or (in special cases -- see below) to replace it. After the expiration of the warranty period, the repair of equipment is carried out at the expense of the consumer. After the expiration of the service life of the product, the manufacturer has the right to refuse the consumer to repair this product.

The activities of service centers are regulated at the legislative level, according to laws the country in which the service is provided. According to the Consumer Rights Act RF, information about the product must contain the warranty period of the product, if it is established.

“Consumer rights in case of defects in the product”:

The consumer, in case of detection of defects in the goods, if they were not specified by the seller, at his choice has the right to:

demand a replacement for a product of the same brand (the same model and (or) article);

demand a replacement for the same product of a different brand (model, article) with a corresponding recalculation of the purchase price;

demand a commensurate reduction in the purchase price;

demand immediate gratuitous elimination of product defects or reimbursement of expenses for their correction by the consumer or a third party;

refuse to fulfill the contract of sale and demand the return of the amount paid for the goods. At the request of the seller and at his expense, the consumer must return the goods with defects.

discovery of a significant defect of the goods;

violation of the deadlines established by this Law for the elimination of defects in goods;

if, in case of repeated failure, the customer was unable to use his product for more than 30 days due to being under repair

Lab No. 9 "Procedure for organizing the repair of refrigeration machines, washing machines"

Purpose of work: To study the procedure for organizing the repair of refrigeration machines, washing machines

Working process:

The principle of operation of the refrigerator can be considered on the example of a filled gas cylinder. The cylinder is filled with gas under high pressure and the temperature of the gas and the cylinder are the same and correspond to the outdoor temperature. If you open the valve, the gas will begin to escape and at the same time the valve will cool sharply. This is due to the fact that the gas in a pressurized cylinder has a very high boiling point, and in the street at low pressure this point is very low. As if you boil a kettle of water and start climbing a mountain, the water in the kettle would continue to boil, because as the pressure drops, the boiling point decreases. So it turns out that in the cylinder the gas is a liquid, and as soon as it leaves the cylinder, the gas immediately boils. When boiling, the gas escapes, and the surface from which it escaped freezes, because the gas takes heat from this surface. So, back to the balloon. If now the cylinder is connected to a cooler, where the products we need will be cooled, and a pump that will drive gas from the cylinder through the cooler into the cylinder, then nothing will work. You need to somehow create a pressure difference. The pressure drop can be arranged using a throttle - a thin tube. The tube will not allow a large amount of liquid gas to pass, it will become a narrowing, and after passing through the tube, the gas enters the evaporator, where there is a lot of space and where the gas will boil.

So, this refrigerator worked for me until it suddenly stopped and started to leak. By the way, if water flows from under the refrigerator, this is not a breakdown, just the condensate drain hose from the chamber has shifted. The hose connects the condensate drain from the refrigerator chamber and the container on the compressor.

Freon-12 is used as a substance that takes heat from products. Freon is a gas, but if it is compressed, the gas will turn into its other state - a liquid. The essence of the refrigerator is very simple: warm products are placed in a heat-insulated cabinet, the walls of which are equipped with tubes through which cold liquid flows. As a result of the fact that there is no heat exchange with the outside, the heat from the products heats the liquid inside the cold tubes and the products are cooled. As a result of the circulation of liquid through the refrigerator, the substance heats up and passes into a state of gas. To maintain the desired temperature, the compressor must operate periodically. The frequency of operation is affected by a temperature sensor, with which we increase or decrease the temperature in the refrigerator.

First, the superheated refrigerant compressed by the compressor in the vapor state enters the condenser - a long zigzag tube. Here it gives up its heat to the surrounding air and, as it cools, turns into a liquid. Then the liquid freon enters the evaporator, which is located inside the freezer. There, at low pressure, it begins to boil and evaporate. And since it evaporates, it means that it takes heat from the chamber and creates cold. The evaporated refrigerant is again sucked in by the compressor, and the cycle repeats.

The main consumer of electrical energy in the refrigerator is a light bulb and a compressor. A light bulb in the refrigerator is needed to illuminate products for those categories of citizens who eat at night. The light comes on when the refrigerator door is opened. It has no effect on the operation of the compressor.

The compressor is used to transfer freon from a gaseous state to a liquid state. The compressor is a sealed tank, which houses an electric single-phase motor and a gas liquefaction mechanism.

Washing machine repair:

If there is no water drain from the washing machine, first check the sewer, or rather the place where your machine is connected to the sewer. Perhaps there is a blockage at the hose connection. Then remove the drain filter, clean it and put it back. If this does not help, we advise you to contact qualified washing machine repair specialists.

The lack of water heating indicates damage to the heating element of the washing machine. Checking the Ten does not take much time, for this you only need a multimeter and the skills to use it. There are 3 contacts on the heating element (phase, zero and ground). Phase and zero must be short-circuited, the ground on them must not be closed.

The lack of water supply comes down to opening the tap to the washing machine. The absence of any action when turning on the washing machine comes down to checking the outlet. Other malfunctions are best eliminated with the help of a service center.

Lab No. 10 "Preparation of standard repair sheets"

Purpose of work: To study the design of standard repair sheets

Working process:

First, conduct a technical inspection with a survey. To do this, hire an expert organization that has all the necessary equipment to inspect the object to be repaired. In addition to the equipment, they must have all the regulatory and technical documentation, on the basis of which they will carry out an inspection and assessment of the degree of damage. A defect is a deviation from the requirements of design documentation. The test results are compared with GOST.

Create different defect lists for different types of work if your organization needs to repair different items, i.e. equipment and premises.

There is no approved single form of the list of defects. You can make it in any form, but you must specify the details provided for in paragraph 2 of Art. 9 of the Federal Law "On Accounting".

Draw up a list of defects based on the technical survey. In the defective statement, it is necessary to reflect, respectively, defects in structures and assemblies, describe all technological and organizational measures to eliminate them. In the same defective statement, you must indicate the amount of repair work and list the main materials needed for the repair. If the brand and type of material is of fundamental importance, you can also indicate this in the document.

Entrust the preparation of the statement to experienced highly qualified workers associated with the repair of equipment or buildings. The list of defects is a document according to which an estimate is made and the repair work performed is checked, therefore the correct and detailed compilation of this document is very important. Since the statement is part of the estimate documentation, it must be signed by both the customer with the stamp "Approved" and the contractor.

If you find significant differences between the description of defects in the estimate of the contractor with whom you entered into a repair contract and the defective statement drawn up by experts, require the contractor to provide a written explanation of this fact and approve this document.

Lab No. 11 « Diagnostics and control of technical indicators »

Purpose of work: To study Diagnostics and control of technical indicators

Working process:

Technical diagnostics - this is an assessment of the technical condition of the object, starting with determining the location and nature of the existing problematic elements and ending with the transition of the object to an inoperable state. Diagnostics is carried out on the basis of the use of modern methods and tools and solves the problem of ensuring the safety, functional reliability and efficiency of the technical object, as well as reducing the cost of its maintenance and reducing losses from downtime as a result of failures.

The diagnostic examination is performed with the equipment turned off. With the help of diagnostic monitoring systems, the problem of effective management of the operation and repair of equipment is solved.

It is difficult to find a physical phenomenon or process that would not be used for diagnostic purposes. Consider some of them, which have found wide application in the electric power industry.

Physical and chemical methods. The energy impact on the insulation of electrical devices leads to its changes at the molecular level. This occurs regardless of the type of insulation and ends with chemical reactions with the formation of new chemical compounds, and under the influence of an electromagnetic field, temperature, vibration, decomposition and synthesis processes simultaneously occur. Analyzing the quantity and composition of emerging new chemical compounds, one can draw conclusions about the state of all insulation elements. The easiest way to do this is with liquid hydrocarbon insulation, which are mineral oils, since all or almost all of the new chemical compounds formed remain in a closed volume.

The advantage of physical and chemical methods of diagnostic control is their high accuracy and independence from electric, magnetic and electromagnetic fields and from other energy influences, since all studies are carried out in physical and chemical laboratories. The disadvantages of these methods are the relative high cost, and the delay from the current time, that is, non-operational control.

Method of chromatographic control of oil-filled equipment. This method is based on the chromatographic analysis of various gases released from oil and insulation during defects inside oil-filled electrical equipment. Algorithms for detecting defects at an early stage of their occurrence, based on the analysis of the composition and concentration of gases, are common, well developed for diagnosing oil-filled electrical equipment and are described in.

Assessment of the condition of oil-filled equipment is carried out on the basis of control:

Limiting concentrations of gases;

The rate of increase in gas concentrations;

The ratio of gas concentrations.

Method for monitoring the dielectric characteristics of insulation. The method is based on the measurement of dielectric characteristics, which include leakage currents, capacitance values, dielectric loss tangent (tg e) and others. The absolute values of tgd, measured at voltages close to the operating voltage, as well as its increments with changes in the test voltage, frequency and temperature, characterize the quality and degree of aging of the insulation.

AC bridges (Schering bridges) are used to measure tgd and insulation capacitance. The method is used to control high-voltage instrument transformers and coupling capacitors.

Infrared thermography method. Losses of electrical energy for heating elements and assemblies of electrical equipment during operation depend on their technical condition. By measuring the infrared radiation caused by heating, it is possible to draw conclusions about the technical condition of electrical equipment. Invisible infrared radiation with the help of thermal imagers is converted into a human-visible signal. This method is remote, sensitive, allowing to register temperature changes in fractions of a degree. Therefore, its readings are highly susceptible to influencing factors, such as the reflectivity of the measurement object, temperature and environmental conditions, since dust and humidity absorb infrared radiation, etc.

The assessment of the technical condition of the elements and assemblies of electrical equipment under load is carried out either by comparing the temperature of the same type of elements and assemblies (their radiation should be approximately the same), or by exceeding the allowable temperature for a given element or assembly. In the latter case, thermal imagers must have built-in equipment to correct the influence of temperature and environmental parameters on the measurement result.

Vibrodiagnostics method. To control the technical condition of the mechanical components of electrical equipment, the relationship between the parameters of the object (its mass and structural rigidity) and the frequency spectrum of natural and forced vibration is used. Any change in the parameters of the object during operation, in particular the rigidity of the structure due to its fatigue and aging, causes a change in the spectrum. The sensitivity of the method increases with the growth of informative frequencies. Estimation of the state by the shift of the low-frequency components of the spectrum is less effective.

Methods for controlling partial discharges in insulation. The processes of occurrence and development of defects in overhead line insulators, regardless of their material, are accompanied by the appearance of electric or partial discharges, which, in turn, generate electromagnetic (in the radio and optical ranges) and sound waves. The intensity of the manifestation of discharges depends on the temperature and humidity of the atmospheric air and is associated with the presence of precipitation. Such a dependence of the obtained diagnostic information on atmospheric conditions requires combining the procedure for diagnosing the intensity of discharges in the overhead insulation of power transmission lines with the need for mandatory control of the temperature and humidity of the environment.

All types and ranges of radiation are widely used for monitoring. The acoustic emission method works in the audio range. A known method of controlling the optical radiation of PR using an electron-optical flaw detector. It is founded on registration spatially the temporal distribution of the brightness of the glow and the determination of defective insulators by its nature. For the same purposes, with varying efficiency, radio engineering and ultrasonic methods are used, as well as the method of controlling ultraviolet radiation using the Filin electron-optical flaw detector.

Method of ultrasonic sounding. The speed of propagation of ultrasound in the irradiated object depends on its condition (presence of defects, cracks, corrosion). This property is used to diagnose the condition of concrete, wood and metal, which are widely used in the energy sector, for example, as a support material. .

Lab No. 12 "Instrument Stations for Defect Detection"

Purpose of work: To study instrument stations for detecting defects.

Working process:

flaw detector -- detection device defects in products from various metallic and non-metallic materials by methods non-destructive testing. Defects include violations of the continuity or uniformity of the structure, corrosion damage zones, chemical deviations. composition and size, etc. technology And technology involved in the development and use of flaw detectors is called flaw detection. Other types of tools are also functionally related to flaw detectors. NDT: leak detectors, thickness gauges, hardness testers, structuroscopes, introscopes And steeloscopes. Flaw detectors are used in transport, various areas mechanical engineering, chemical industry, oil and gas industry, energy, construction, research laboratories to determine the properties solid body and molecular properties in other industries; are used to control parts and blanks, welded, soldered and adhesive joints, to monitor the details of units. Some flaw detectors allow you to check products that move at a significant speed (for example, pipes during rolling), or can themselves move at high speed relative to the product (for example, rail flaw detectors, trolleys and flaw detector cars). There are flaw detectors for testing products heated to high temperatures.

Pulse flaw detectors use the echo method, shadow and mirror-shadow inspection methods.

The echo method is based on sending short pulses of ultrasonic vibrations into the product and recording the intensity and arrival time of echo signals reflected from discontinuities (defects). To control the product, the echo flaw detector sensor scans its surface. The method makes it possible to detect surface and deep defects with different orientations.

With the shadow method, ultrasonic vibrations, having met a defect on their way, are reflected in the opposite direction. The presence of a defect is judged by a decrease in the energy of ultrasonic vibrations or by a change in the phase of ultrasonic vibrations that envelop the defect. The method is widely used to control welds, rails, etc.

The mirror-shadow method is used instead of or in addition to the echo method to detect defects that give weak reflection of ultrasonic waves in the direction of the dual-combined transducer. Defects (for example, vertical cracks) oriented perpendicular to the surface along which the transducer is moved (input surfaces) give very weak scattered and bottom signals due to the fact that on their surface the longitudinal wave is transformed into a bow wave, which in turn radiates side waves that carry away energy. An example of using the mirror-shadow method -- control rails for vertical cracks in the neck. In terms of sensitivity, this method is usually 10-100 times worse than the echo method.

Programming the operating mode of household machines and appliances. Repair of household electrical appliances. Heating elements defective

Laboratory work No. 8 "Procedure for organizing service maintenance of electrical machines"

Repair of large household appliances

Types of repair of household appliances

Repair of household appliances

Maintenance Tasks

Regulatory documents

Classification of types of maintenance

Maintenance and repair system

What is a maintenance and repair system

Maintenance of the maintenance and repair system

Implementation of works

Maintenance terms

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