Electrical Operation and Repair Project

Contents

1. Introduction of _____________________________________

2. Characteristics of the design object __________

3. List of lighting installations of the barn _____

4. Design part _______________________________

5. Maintenance of electric motors _

6. Current repair (TR) of electric motors __________

7. Inspections of lighting installations _______________

8. List of literature ______________________________

Introduction

Electricity is widely used in modern livestock complexes, poultry farms, in greenhouse and refrigeration farming, in crop improvements and other works. The use of electricity in agricultural production reduces the labor burden of work, increases labor productivity.

In agriculture, there is a gradual transition to full automation of all production processes based on wide electrification, automation and the introduction of electrical technology. Most of the electricity is converted into mechanical energy using electric drives of agricultural machines.

In the conditions of hard work of enterprises, the repair of electrical equipment should be carried out in an extremely short time, which is possible with a high level of organization of repair work. Since the needs of enterprises in transformers, electric machines and apparatus are not yet fully satisfied, the timely and high-quality repair of these electrical equipment has become one of the main factors ensuring the normal operation of enterprises.

Maintenance of electric motors

Maintenance is carried out at the installation site without dismantling and disassembly. The scope of maintenance includes: cleaning the motor from dust and dirt; check of grounding serviceability, attachment of electric motor and its elements, degree of heating and level of vibration and noise, reliability of contact connections; measurement of insulation resistance and elimination of detected faults. Motors with phase rotor check condition of contact rings and brush mechanism.

The terms of maintenance of electric motors depend on the characteristics of the rooms and working machines with which they work. Maintenance of electric motors of series 4A, D, AO2CX is carried out 1 times every three months, except for electric motors installed on grain grinders, thresholders, presses, feed grinders (dusty wet rooms), for which maintenance is carried out 1 times every one and a half months. Electric motors operating outdoors or under a canopy have the same service periodicity. For engines of milk vacuum pumps and pasteurizers (particularly raw rooms) maintenance is performed 1 every two months.

The periodicity of maintenance for electric motors of the AO2 series installed in dry and wet, as well as damp rooms, for electric motors used in dusty and particularly damp rooms is determined in accordance with PPRE - the system of scheduled preventive repairs of electrical equipment.

Motor Maintenance (TR)

They are carried out either at the place of their installation, or at the maintenance point, in the workshop, etc. Ongoing repairs at the installation site of electrical equipment are carried out by specialized field teams .

In accordance with PPRE, the scope of current repair of the electric motor includes: cleaning from dust and dirt, disconnection from supply wires and grounding, removal at the installation site and disassembly, winding cleaning, measurement of winding insulation resistance and, if necessary, winding drying, flushing the bearings, checking and replacing them if necessary, repairing or replacing the damaged lead wires of the winding and terminal panel, terminal boxes, assembly, lubrication of bearings, idling test, painting and, if necessary, installation of the electric motor on the work station, alignment with the work machine and load testing .

Electric motors with a phase rotor check the condition of contact rings, if necessary, perform their groove and grinding, adjust the brush mechanism and, if necessary, replace the brushes.

When drying the windings of the motor, moisture is removed from the pores and cracks of the winding, but the cracks and pores in the lacquer film themselves are preserved. Therefore, the probability of rather fast humidification of the motor winding during its "breathing" during operation, and therefore the probability of breakdown, remains. Elimination of pores and cracks of the lacquer film of the winding conductors makes it possible to avoid its humidification for a long period of time. Cracks and pores can be eliminated only by impregnating the winding in the varnish .

Impregnation of the winding increases its reliability, but complicates the repair technology, requires the presence of impregnation baths, lacquer storage tanks, etc. In addition, the time of the motor in repair is increased, it may be longer than the downtime between the working cycles. In this case, it will be necessary to replace the repaired motor with a backup one. Therefore, it is necessary to carry out a thorough diagnosis of the state of the electric motor in each case before the current repair and, on the basis of the data obtained, to decide the issue of the scope and place of repair .

The periodicity of the current repairs of the 4A, D, AO2CX series motors in accordance with the PPRE is 24 months, with the exception of motors installed on milk vacuum pumps and pasteurizers in especially damp rooms in which humidity exceeds 98%, in this case the periodicity of the current repairs is 18 months.

The periodicity of TR of A02 series motors is 24 months for dry, wet (humidity up to 75%) and wet rooms and 18 months for dusty and particularly damp rooms (humidity up to 98%), excluding electric motors of grain grinders, thresholders, presses, feed grinders, for which the periodicity is 12 months. The same frequency of TP are AO2 series motors operating outdoors or under a canopy.

The EAP system determines the periodicity of maintenance and repair in relation to the room and the working machine for which the electric motor is used. Influence of electric motor operation mode on change of winding insulation characteristic is not taken into account in determination of maintenance and TR periodicity. In addition, PPRE does not take into account the life of the electric motor. In accordance with PPRE, the new electric motor, which was first subjected to maintenance or TR, and the electric motor, which has already repeatedly passed maintenance and TR, have the same periodicity. The periodicity of maintenance and maintenance of electric motors installed on working machines after overhaul or modernization is not specified.

Under these conditions, the importance of electrical equipment diagnostics and the role of the heads of the electrical service of the economy in compiling monthly and annual maintenance and maintenance schedules of electrical equipment increases .

High-quality diagnostics of electrical equipment will allow adjusting the terms of maintenance and maintenance of electrical equipment. Using diagnostics, it is possible to identify and withdraw from work for repair (modernization) or for write-off electrical equipment that has developed its resource and has maximum permissible reliability parameters. As a result, the risk of sudden failure of electrical equipment and emergency shutdown of the process is eliminated.

The modernization of the electrical equipment put into repair in a timely manner will increase its reliability and, as a result, ensure the continuity of the technological process of agricultural production. As a result of diagnostics, it can be decided to extend the time between maintenance and maintenance for electrical equipment with high reliability parameters, which will save the cost of maintaining electrical equipment.

Consider measures to improve the operational reliability of electric motors .

The main reasons for the failure of electric motors used in agricultural production: non-compliance with difficult environmental conditions; non-conformance or absence of protection against incomplete-phase operation modes and emergency overloads; Insufficient level of operation .

To eliminate the first reason, the following measures are taken: high-reliability motors are produced; modernize the electric motors of the old series during repair; electric motors are pulled out of wet aggressive medium.

Increasing the reliability of electric motors, factories produce highly specialized versions for agricultural production conditions. Electric motors of the second series of agricultural design AO2CX well justified themselves in operation.

When working in livestock premises, the service life of agricultural electric motors reaches 6... 8 years, and the second series of general industrial performance - only 1... 2 years .

The fourth series of general industrial electric motors used the same insulating and active materials as in AO2CX engines. Therefore, the 4A and A02CX series motors operate with the same reliability. The difference between the manufactured motors of the specialized version of 4ACX consists only in anodizing or nickel-plating the engine fasteners and better painting.

Upgraded 4AM Series IV motors have increased reliability. The domestic electric industry, together with the countries of the socialist commonwealth, began to produce a new series of AI engines (international), the characteristics and reliability of which are further improved.

Thus, modern electric motors of general industrial design are universal, since they can be used in particularly raw, chemically active livestock premises in which the moisture content is 80... 100%, ammonia - 2... 140 mg/m3, hydrogen sulfide - 10... 90 and carbon dioxide - 0.03... 0.88 mg/m3, dust content - up to 240 g/m3 .

In agricultural production, a variety of series of electric motors are used, including the old ones - A, AO and A2, AO2.

With major and ongoing repairs, it is advisable to modernize the old series of electric motors. Usually, electric machine-building plants in the manufacture of electric motors use double impregnation of windings. Electrical repair plants sometimes depart from the repair technology and use only a single impregnation of the winding, which significantly reduces the reliability of the motors. As the simplest modernization of electric motors during their repair, the use of not two, but three times impregnation can be considered .

Lighting plant inspections

During inspections of lighting electrical installations, the condition of wiring, boards, lighting devices, circuit breakers, switches, sockets and other elements of the installation is checked. They also check the reliability of the contacts available in the installation: weakened contacts must be tightened, and burned ones must be cleaned or replaced with new ones.

Replacement of lamps in lamps

In the production shops of industrial enterprises, there are two methods of changing lamps: individual and group. In the individual method, the lamps are replaced as they fail; in the group method, they are replaced by groups (after they have served the prescribed number of hours). The second method is economically more advantageous, since it can be combined with cleaning of lamps, but is associated with a high consumption of lamps .

When replacing, do not use lamps of greater power than is permitted for the lighting fixture. Excessive power of lamps leads to unacceptable overheating of lamps and cartridges and worsens the state of insulation of wires.

Lamps and fittings are cleaned from dust and soot in workshops with a small release of pollutants (mechanical and tool shops, machine halls, leather water, etc.) twice a month; with a large release of pollutants (blacksmiths and foundries, spinning factories, cement plants, mills, etc.) four times a month. All luminaire elements are cleaned - reflectors, diffusers, lamps and external surfaces of fittings. Windows for natural lighting are cleaned as they are contaminated.

Working and emergency lighting in production shops is switched on and off according to the schedule only when natural lighting is not enough for the work.

Inspections and tests of lighting installations during operation

Electric lighting plants are subjected to a number of checks and tests during operation. Insulation resistance of working and emergency lighting is checked. Serviceability of emergency lighting system is checked by disconnecting working lighting at least once a quarter. The machine or emergency lighting switching unit is checked once a week during daytime. For stationary transformers, the voltage of 12 - 36 V is tested 1 times a year, and for portable transformers and lamps on 12 - 36 V - every three months .

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