The results of the analysis of the organization of labor and measures to improve it.

Technological maps provide a detailed technically sound description of operations for the current repair of equipment of traction substations, substations and PPS and must be strictly observed when performing work. They define the categories of work in relation to security measures, the composition of the performers and their qualifications, set out the basic requirements that ensure the safety of personnel. The number of performers and security measures in the preparation of the workplace are specified by the order (order) issued for the production of work.

The name of the position of an electrician in this collection is accepted in accordance with the Qualification characteristics and categories of remuneration for positions of managers, specialists and employees according to the industry tariff scale (approved by the indication of the Ministry of Railways dated 10/18/96 No. A-914u) and the Collection of changes and additions to qualification characteristics and payment categories labor positions of managers, specialists and employees according to the industry wage scale (Moscow, PVC of the Ministry of Railways of the Russian Federation, 1999). The name of the profession and the category of qualification of an electrician of a traction substation - according to the Unified Tariff and Qualification Reference Book of Works and Professions of Workers (ETKS), Issue 56 and the Collection of Tariff and Qualification Characteristics of the Professions of Workers Employed in Railway Transport (Moscow, PVC MPS RF, 1999).

When performing the work provided for in the collection, instruments, tools and devices manufactured by the electrical industry and designed specifically for work in electrical installations of traction substations are used. Recommended lists of them are given in each technological map. In addition to the recommended ones, other types of devices with similar or close characteristics can be used.

Performers must be provided with the necessary tools, devices and fixtures that meet the technical conditions. They are cared for by the personnel performing the main work.

All service personnel involved in the processes must have sufficient experience and pass the safety test.

The limits of numerical indicators given in the collection, in which “up to” is indicated, should be understood inclusively, “not less than” - are the smallest.

When this collection is published, the collection “Cards of technological processes for capital, current repairs and preventive tests of specific equipment of traction substations of electrified railways”, approved on 14.01.94 by the Ministry of Railways of the Russian Federation, No. TsEE-2, becomes invalid.

2. Transformers Technological map No. 2.1.

Current repair of power transformers10000 - 63000 kVA1. Cast

Electromechanic - 1

Traction substation electrician 4th category - 1

Traction substation electrician 3rd category - 1

2. Terms of work

The work is being done:

With stress relief

Alongside

3. Protective equipment, devices, tools, fixtures and materials:

Safety helmets, safety belt, ladder, grounding, shorts, dielectric gloves, megohmmeter for voltage 1000 and 2500 V, stopwatch, thermometer, level, pump with pressure gauge and hose, wrenches, combination pliers, screwdrivers, scraper, brushes, container for draining sediment, glass containers with a ground stopper for oil sampling, indicator silica gel, silica gel, transformer oil, TsIA-TIM lubricant, white spirit, moisture-oil-resistant varnish or enamel, spare oil-indicating glasses, rubber gaskets, cleaning material, rag

4. Preparatory work and admission to work

On the eve of the work, submit an application for taking the transformer out for repair.

Check the serviceability and expiration dates of protective equipment, devices, prepare tools, mounting devices and materials.

After issuing the work order, the work foreman should be instructed by the person who issued the work order.

4.4. Operational personnel to prepare the workplace. For the foreman to check the implementation of technical measures for the preparation of the workplace.

Get the team to work.

The foreman should instruct the members of the team and clearly allocate responsibilities between them.

End of technology card№ 2.2.

Note. All operations with oil filled and 110-220 kV bushings must be carried out in cooperation with a RRU specialist.

Current repairs of transformers are carried out in the following terms:

• transformers of central distribution substations - according to local instructions, but at least once a year;
• all others - as needed, but at least once every 3 years.

The first overhaul of substation transformers is carried out no later than 6 years after commissioning, and subsequent repairs are carried out as necessary, depending on the measurement results and the condition of the transformer.

The scope of the current repair includes the following works:

• external inspection and repair of damages,
• cleaning of insulators and tank,
• descent of dirt from the expander,
• adding oil and checking the oil gauge,
• checking thermosyphon filters and, if necessary, replacing the sorbent,
• checking the condition of the blow-out fuse, circulation pipes, welds, flange seals,
• security check,
• taking and checking oil samples,
• carrying out preventive tests and measurements.

The scope of the overhaul includes all the works provided for by the current repair, as well as repair of the windings, magnetic circuit, checking the condition of the contact connections of the windings to the voltage switch and terminals, checking the switching devices, repairing their contacts and the switching mechanism, checking the condition of the transformer tank, expanders and pipelines, entry repair.

The transformer is taken out of operation for repairs under the following conditions:

• strong internal crackling characteristic of an electrical discharge, or uneven noise,
• abnormal and constantly increasing heating during normal load and cooling,
• ejection of oil from the expander or destruction of the exhaust pipe diaphragm,
• oil leaks and lowering its level below the permissible limit,
• upon receipt of unsatisfactory results of the chemical analysis of the oil.

Aging of the winding insulation and moistening of the oil can lead to ground faults and phase-to-phase faults in the transformer windings, resulting in abnormal operating noise of the transformer.

A “steel fire” failure, which occurs due to a violation of the interlayer insulation of the core or the insulation of the tie bolts, leads to an increase in the heating of the case and oil under normal load, humming and characteristic crackling inside the transformer.

Increased “humming” in the transformer can occur due to the weakening of the magnetic circuit pressing, significant phase load asymmetry, and when the transformer is operating at increased voltage. A crackle inside the transformer indicates an overlap (but not a breakdown) between the winding or case taps, or an open ground that could cause electrical discharges from the winding or case taps.

Breaks in the windings are a consequence of the poor quality of the contact connections in the windings.

An open in the primary winding of a transformer connected in delta-star, delta-delta and star-star circuits leads to a change in the secondary voltage.

To determine the scope of the forthcoming repair, a transformer fault detection is carried out, which is a set of works to identify the nature and degree of damage to its parts. Based on fault detection, the causes, extent of damage and the necessary amount of repair of the transformer are determined. At the same time, the needs for materials, tools, fixtures for the repair are determined.

Disassembly of transformers

The disassembly of the transformer during the overhaul is carried out in the following order. Oil is drained from the expander, the gas relay, safety pipe and expander are removed; put plugs on the holes in the tank lid. With the help of lifting mechanisms, slings lift the cover with the active part of the transformer by lifting rings. Raising it by 10 - 15 cm, inspect the condition and position of the sealing gasket, separate it from the tank frame with a knife and, if possible, save it for reuse. After that, the active part is removed from the tank in sections convenient for removing oil sludge, washing the windings and the core with a jet of heated oil and fault detection. Then the active part is installed on a pre-prepared platform with a pallet. Having raised the active part of the transformer 20 cm above the level of the tank, they move the tank to the side, and the active part is installed on a solid platform for ease of inspection and repair. The windings are cleaned of dirt and washed with a stream of transformer oil heated to 35 - 40 ° C.

If the transformer inputs are located on the walls of the tank, then first remove the cover, drain the oil from the tank 10 cm below the input insulators and, having disconnected the inputs, remove the insulators, and then remove the active part from the tank.

Dismantling, inspection and repair of the transformer is carried out in a dry, closed and adapted room for the production of these works.

After removing the active part, the state of the magnetic circuit is checked - the density of the assembly and the quality of the lamination, the strength of the fastenings of the yoke beams, the condition of the insulating sleeves, washers and gaskets, the degree of tightening of nuts, studs, tie bolts, the state of grounding. Pay special attention to the condition of the windings - the wedging on the rods of the magnetic circuit and the strength of the fit of the windings, the absence of traces of damage, the condition of the insulating parts, the strength of the connections of the leads, dampers.

During the overhaul of the transformer, in addition to the above works, if necessary, the yoke of the magnetic circuit is unloaded with the iron being pressed out and the winding coils are removed.

Repair of the transformer magnetic circuit

The most common type of magnetic circuit of power transformers is flat (rod) (Fig. 123, a). The cross section of the yoke 6 and 7 is rectangular in shape, and the rod is in the form of a multi-stage figure 3, close to a circle. The magnetic circuit is pulled together by yoke beams 5 n 8 using through studs 4 and tie rods 2.

Rice. 123. Flat (a) and spatial (b) magnetic cores of the transformer:
1 - axes of the rods; 2 - vertical tie rods: 3 - multi-stage rod figure; 4 - through studs; 5, 8 - yoke beams; 6, 7 - cross sections of the yoke; 9 - support beam; 10 - bandage; 11 - insulating tube; 12 - insulating gasket; 13 - Belleville spring, 14 - insulating gasket.

Transformers with a power of 250 - 630 kVA are produced with pinless magnetic cores. The pressing of the rod plates in these transformers is carried out by means of strips and wedges driven between the magnetic circuit and the cylinder. Recently, the industry has been manufacturing 160 - 630 kVA power transformers with a spatial magnetic circuit (Fig. 123, b). The magnetic core of such a transformer is a rigid structure, the vertical axes of the rods 1 of which have a spatial arrangement. The steel sheets of the rod are pressed with a bandage 10 of insulating material or a steel tape with a lining of insulating material instead of studs. The upper and lower yokes are pulled together by vertical tie rods 2 by means of nuts, under which belleville springs 13 are placed. Insulating gaskets 14 are used to isolate the studs from the yoke, and insulating tubes 11 are used from the rods. The entire structure of the magnetic circuit is fastened with studs to the support beams 9.

The spatial magnetic circuit is made butt instead of laminated, since the yoke and rods are connected into a magnetic circuit by docking. To avoid shorting between the steel of the yoke and the rod, an insulating gasket 12 is laid between them.

In previously produced transformers, the magnetic cores were pulled together by horizontal studs, insulated from the steel of the magnetic core and passing through holes in the plates.

The disassembly of the magnetic circuit is as follows: unscrew the top nuts of the vertical studs and the nuts of the horizontal studs, remove them from the holes in the yoke, remove the yoke beams and proceed to unload the upper yoke of the magnetic circuit, starting with the outermost packages of two or three plates. The plates are folded in the same sequence in which they are removed from the yoke and tied into packages.

In magnetic cores tied with horizontal studs, the insulation of the studs is often damaged, which leads to short circuits of steel plates and causes strong heating of iron by eddy currents. During the repair of a magnetic circuit of this design, the insulating sleeve is replaced with a new one. In the absence of spares, the sleeve is made from bakelite paper, wound on a hairpin, impregnated with bakelite varnish and baked. Insulating tubes for studs with a diameter of 12 - 25, 25 - 50 and 50 - 70 mm are made with a wall thickness of 2 - 3, 3 - 4 and 5 - 6 mm, respectively. Pressure insulating washers and spacers for studs are made of electrical cardboard with a thickness of 2 mm or more.

Restoration of the broken insulation of the magnetic circuit plates begins with boiling the sheets in a 10% sodium hydroxide solution or in a 20% trisodium phosphate solution, followed by washing the sheets in hot (50 - 60 ° C) running water. After that, a mixture of 90% hot-drying varnish No. 202 and 10% pure filtered kerosene is carefully sprayed onto a steel sheet heated to 120 ° C. Glyptal varnish No. 1154 and benzene and gasoline solvents can be used to isolate the plates. After applying the insulation layer, the plates are dried at 25 C for 7 hours. For large volumes of work, special machines are used for varnishing the plates, and special ovens are used for baking and drying them.

When replacing worn-out plates, new steel plates made according to samples or templates are used. In this case, the sheets are cut in such a way that the busbar side of the plates is along the rolling direction of the steel. Holes for tie rods in the plates are made by stamping, not drilling. After making the plate, I cover it! isolated in one of the above ways.

Laying starts from the central package of the middle rod, laying the plates with the insulated side inside the yoke. Then, the extreme packages are blended, starting with long plates and avoiding overlapping of narrow plates of rods and gaps in the joints. The holes in the yoke plates must exactly match the holes in the rod plates. The plates are leveled by hammer blows on a copper or aluminum bus. A well-stitched yoke has no gaps between the layers of plates, gaps, or damage to the insulation between the plates at the junction.

After leveling the upper yoke, the installation of the upper yoke beams is performed and pressing with their help of the magnetic circuit and windings. The yoke beams in transformers are isolated from the plates with an annular washer made of electric cardboard 2-3 mm thick with pads attached on both sides.

On both sides of the upper yoke, yoke beams are installed into the openings of the beams, four vertical tie rods with insulating tubes are inserted, cardboard and steel washers are put on the ends of the studs and tightened with nuts, Grounding of the vertical yoke beams is carried out with several tinned copper tapes.

Nuts are tightened on the tie rods, pressing the upper yoke, and the nuts of the vertical pressing rods are evenly tightened; the winding is pressed, and then the upper yoke is finally pressed. They measure the insulation resistance on the studs with a megger, unscrew the nuts on the studs so that they do not unscrew themselves during the operation of the transformer.

Repair of transformer windings

Windings of power transformers are the main element of the active part. In practice, windings are damaged much more often than other elements of the transformer.

Depending on the power and rated voltage, various winding designs are used in transformers. So, in power transformers with a power of up to 630 kVA at low voltage, mainly single- and double-layer cylindrical windings are used; with a power of up to 630 kV -A at the highest voltage of 6, 10 and 35 kV, multilayer cylindrical windings are used; with a power of 1000 kVA and more, screw windings are used as LV windings. At the helical winding, the rows of wound turns are arranged so that oil channels are formed between them. This improves winding cooling conditions due to cooling oil flows. Helical winding wires are wound on paper-bakelite cylinders or split templates using electrical cardboard strips and spacers, which form vertical channels along the inner surface of the winding, as well as between its turns. Screw windings have high mechanical strength. Repair of windings of power transformers can be carried out without unloading or with unloading of magnetic circuits.

Slight deformation of individual turns, damage to small sections of wire insulation, loosening of windings, etc., are eliminated without dismantling the active part of the transformer.

When repairing the windings without removing them, the deformed turns of the windings are straightened by hammer blows on a wooden gasket superimposed on the turn. When repairing turn insulation without dismantling the windings, oil-resistant varnished cloth (LKhSM brand) is used, which is applied to the bare conductor of the turn. The conductor is pre-wrung out with a wooden wedge for the convenience of working on the insulation of the coil. Lacquered cloth tape is wound overlapping with overlapping of the previous turn of the tape on V2 part of its width. A general bandage of cotton tape is applied to the coil isolated with varnished cloth.

Pre-pressing of weakened windings, the design of which does not provide for pressing rings, is carried out using additional insulating gaskets made of electrical cardboard or getinaks. To do this, a wooden wedge is temporarily hammered into adjacent rows of winding to weaken the density of the gaskets, thus ensuring the entry of the driven pressing gasket in the weakened place. Clog the pressure pad and move on to the next place. This work is carried out along the entire circumference of the winding, clogging the spacers between the yoke and additional insulation.

Significant damage to the windings (turn short circuits, breakdown of the insulation of the windings on the steel of the magnetic circuit or between the HV and LV windings, etc.) is eliminated after the windings are removed.

To dismantle the windings, the magnetic circuit of the transformer is unloaded. Work begins with unscrewing the upper nuts of the vertical studs. Then the nuts of the horizontal studs are unscrewed, the horizontal pressing studs are removed from the hole in the yoke and the yoke beams are removed. One of the yoke beams is pre-marked with a symbol (VN or NN).

The unloading of the plates of the upper yoke of the magnetic circuit begins simultaneously from the side of the HV and LV, taking out 2 - 3 plates alternately from the extreme packages. The plates are laid in the same order in which they were removed from the yoke. and tied into packages. To protect the plates of the magnetic core rods from damage to the insulation and scattering, they are tied by threading a piece of wire into the hole for the pin.

The dismantling of the windings of transformers of small power is carried out manually, and with a power of 630 kV A and above - using removable devices. Before lifting, the winding is firmly tied with a rope along the entire length and the grips of the device are carefully brought under the winding.

Damaged coils are replaced with new ones. If a new coil during storage could be moistened, then it is dried in a drying chamber or with infrared rays.

The copper wire of the failed coil is reused. To do this, the wire insulation is burned in the furnace, washed in water to remove the remaining insulation, straightened and wound with new insulation. For insulation, cable or telephone paper 15–25 mm wide is used, wound onto the wire in two or three layers. The bottom layer is applied end-to-end, and the top layer is overlapped with overlapping of the previous turn of the tape by ½ or ¼ of its width. Strips of insulating tape are glued together with bakelite varnish.

Often, a new coil is made to replace a failed coil. The method of manufacturing windings depends on their type and design. The most perfect design is a continuous winding, produced without breaks. In the manufacture of a continuous winding, the wires are wound on a template wrapped with a sheet of electrical cardboard 0.5 mm thick. Laths with spacers are laid on the cylinder installed on the winding machine to form channels and the end of the winding wire is fixed with cotton tape. Winding of turns of continuous winding can be done clockwise (right-hand version) and counter-clockwise (left-hand version). Turn on the machine and guide the winding wire evenly along the cylinder. The transitions from one coil to another during winding are determined by the settlement note and are performed in the interval between the same two rails. The places of wire transitions are additionally insulated with boxes of electrical cardboard, fixed with a cotton tape. After winding is completed, bends are made (external and internal), arranging them in accordance with the drawings, and isolating them. At the ends of the coil, insulating support rings are installed and removed from the machine. The coil is pulled together with metal plates by means of tie rods and sent for drying in a drying chamber.

The scheme of the algorithm and the technological map for the manufacture of a multilayer winding of a HV transformer with a power of 160 kV A and a voltage of 10/04 kV are given below.

The winding is dried at a temperature of about 100 ° C for 15 - 20 hours, depending on the volume of the coil, the degree of insulation moisture, the drying temperature, etc. Then it is pressed, impregnated at a temperature of 60 - 80 ° C with TF-95 varnish and baked at a temperature of 100 ° C for 10-12 hours. The winding is baked in two stages - first, the impregnated winding is dried at a slightly lower temperature to remove solvents remaining in the insulation, and then the temperature is increased to bake the winding. Drying and baking the winding increase the dielectric strength of the insulation and the mechanical strength of the coil, giving it the necessary solidity.

Rice. 124. Machine for winding transformer windings:
1 - electric motor; 2 - body; 3 - belt drive; 4 - counter of turns; 5 - clutch; 6 - spindle; 7 - textolite disk; 8 - nut; 9 - template; 10 - control pedal.

For the manufacture of windings, various machines are used. The console winding machine for winding transformer windings of small and medium power (up to 630 kVA) (Fig. 124) consists of a template with two wooden counter wedges 9, clamped textolite disks 7 and fixed nuts 8. The template is mounted on a spindle 6, which rotates from an electric motor 1 through a belt drive 3. To count the number of turns of wire, the machine has a coil counter 4. The finished winding is removed from the template after unscrewing the nut 8, removing the right disk and spreading the wedges 9 of the template. The machine is controlled by a pedal 10 connected to the clutch 5.

Rice. 125. Insulation of the magnetic circuit (a) and wedging of the windings (c) when installing the transformer windings:
1 - yoke insulation; 2 - a cylinder made of electric cardboard; 3 - round rods; 4 - slats; 5 - extension.

The windings are mounted on the rods of the magnetic circuit, previously tightly pulled together with a keeper tape (Fig. 125). The windings mounted on the magnetic circuit are wedged using beech strips and rods, having previously laid two layers of electric cardboard between the HV and LV windings. The beech strips rubbed with paraffin are first inserted between the wrappers to a depth of 30 - 40 mm, and then they are hammered alternately in opposite pairs (Fig. 125, b). To maintain the cylindrical shape of the windings, first round rods 3 are hammered, and then strips 4 with a hammer using a wooden extension 5, avoiding splitting the ends of the rods or strips.

In the same way, the LV winding is wedged on the rod with round wooden studs, hammering them around the entire circumference of the winding between the cylinder and the steps of the magnetic circuit rod.

After the end of the wedging of the windings, the upper yoke insulation is installed and the upper yoke of the magnetic circuit is charged.

In transformers of small power, for connecting windings with switch contacts and input rods, the ends of the wires are carefully stripped over a length of 15 - 30 mm (depending on their cross section), superimposed on each other, connected with a bracket of tinned copper tape 0.25 - 0 thick, 4 mm or a bandage of tinned copper wire 0.5 mm thick and soldered with POS-30 solder, using rosin or borax as a flux.

In high-power transformers, copper-phosphorus solder with a melting point of 715 ° C is used to connect the ends of the windings and attach them to the taps. The place of soldering is cleaned, insulated with paper and varnished cloth up to 25 mm wide and coated with GF-95 varnish. Winding taps are made with a damper at the end to protect the wire from breaking. The taps of the HV windings along the entire length are varnished GF-95.

The insulating parts of the transformer core are made of cardboard, paper, wood. These materials are hygroscopic and absorb moisture from the surrounding air, reducing their electrical insulating properties. For high electrical strength of the core insulation, it is dried in ovens in special cabinets, with a blower, etc.

The most commonly used in practice is the method of drying in its own heated tank: when an alternating current passes through a special winding superimposed on the insulated surface of the tank, a strong magnetic field is formed, which closes through the steel of the tank and heats it.

Dry the transformers in a tank without oil (to speed up the drying process of the active part and preserve the quality of the oil and winding insulation). The magnetizing winding placed on the tank heats the tank. The winding turns are placed on the tank in such a way that at least 60% of the winding is in the lower part of the tank. During warm-up, the tank lid is also insulated. The increase in temperature is controlled by changing the number of turns of the winding, while not allowing the temperature of the windings to rise above 100°C, and the temperature of the tank above 110-120°C.

The indicator of the end of drying is the steady value of the insulation resistance of the windings for 6 hours at a constant temperature not lower than 80°C. After drying is completed and the temperature of the windings decreases to 75-80 °C, the transformer tank is filled with dry oil.

Transformer tank repair

The inner surface of the tank is cleaned with a metal scraper and washed with used transformer oil. The dents are heated with a gas burner flame and straightened with hammer blows. Cracks on the edge and the wall of the body are welded by gas welding, and in the pipe - by electric welding. To check the quality of welding, the outer side of the seam is cleaned and covered with chalk, and moistened with kerosene from the inside (if there are cracks, the chalk is wetted with kerosene and darkens). The tightness of the body is checked by filling the tank with used oil for 1 hour at a temperature not lower than 10°C.

Before welding, cracks at its ends are drilled through holes with a diameter of several millimeters. The edges of the crack are chamfered and welded by electric welding. The density of the seam is controlled using kerosene. Loose seams are cut out and welded again.

Extender repair

When repairing the expander, check the integrity of the glass tube of the oil indicator, the condition of the seals. The defective flat glass or glass tube of the oil indicator is replaced. Rubber gaskets and seals that have lost elasticity are replaced with new ones made of oil-resistant rubber. The sediment is removed from the bottom of the expander and washed with clean oil. The cork is rubbed with a fine abrasive powder. The gland packing is replaced with a new one, which is prepared from an asbestos cord soaked in a mixture of fat, paraffin and graphite powder.

Check the strength and tightness of the fastening of the glass diaphragm at the safety pipe; the inside of the pipe is cleaned of dirt and washed with clean transformer oil.

When repairing transformers, special attention is paid to the safety of insulators and the reinforcement of the bushings. Chips up to 3 cm² or scratches up to 0.5 mm deep are washed with acetone and covered with two layers of bakelite varnish, drying each layer in an oven at a temperature of 50 -60 ° C.

Repair of reinforcing seams

Reinforcement joints are repaired as follows: the damaged section of the joint is cleaned with a chisel and filled with a new cementing composition. If the reinforcing seam is destroyed by more than 30%, the bushing is completely replaced. The cementing composition per serving of one input is prepared from a mixture consisting (by weight) of 140 parts of magnesite, 70 parts of porcelain powder and 170 parts of magnesium chloride solution. This composition is used for 20 minutes. After the putty has cured, the seam is cleaned and coated with 624C nitro enamel.

Cleaning the thermosyphon filter

The thermosiphon filter is cleaned from the old sorbent, the internal cavity is washed with transformer oil, filled with a new absorbent and attached to the transformer tank on flanges.

Switch repair

Repair of the switch consists in the elimination of defects in the contact connections, insulating tubes of the cylinders and sealing devices. The contacts are cleaned, washed with acetone and transformer oil. Burnt and melted contacts are filed with a file. Broken and burnt contacts are replaced with new ones. Minor damage to the insulation of the tube or cylinder is restored with two layers of bakelite varnish. The weakened points of connection of the winding taps are soldered with POS-30 solder.

The repaired switch is assembled, the installation site is wiped with a rag, the gland seal is inspected, the switch handle is replaced and the studs are tightened. The quality of the switch is checked by switching its positions. Switching should be clear, and the locking pins in all positions should fully enter their sockets.

Checking the operation of a switching device for voltage regulation under load consists in determining the correct operation of the moving contacts in series. a and b switch and contactors K1 and K2. Violation of the sequence of operation of these elements of the switching device can lead to serious damage to the transformer and an accident in the electrical network.

Transformer Assembly

The assembly of a transformer without an expander, the inputs of which are located on the walls of the tank, begins with lowering the active part into the tank, then the inputs are installed, the taps from the windings are connected to them and the switch, and the tank cover is installed. Small power transformer covers are installed on the lifting studs of the active part, completed with the necessary parts, and in more powerful ones, they are assembled separately. During assembly, the correct installation of sealing gaskets and the tightening of the fixing nuts are monitored. The length of the lifting studs is adjusted so that the removable part of the magnetic circuit and the cover are correctly positioned in their places. Pre-determine the required length of the lifting studs with a wooden lath. The length of the studs is adjusted by moving the nut.

The active part of the transformer with the help of lifting devices is lowered into the tank with a sealing gasket made of oil-resistant sheet rubber (Fig. 126).

Rice. 126. Gasket joint (a) and methods of installing the gasket (s) when sealing the tank with an oil-resistant rubber gasket:
1 - tank wall; 2 - limiter; 3 - tank cover; 4 - gasket; 5 - tank frame.

Brackets are installed on the tank cover for attaching an expander with an oil indicator, a safety pipe, a switch actuator, a gas relay and a blowout fuse.

The transformer is filled with dry transformer oil to the required level according to the oil indicator of the expander, the tightness of fittings and parts is checked, as well as the absence of oil leakage from joints and seams.

Including reconstruction (change of structural elements) and modernization (change of rated voltages and capacities).

We always fulfill our obligations, so our customers can count on a decent level of service and quality work.

Current repair of transformers with a capacity of 10,000 - 63,000 kV-A 1. Composition of performers

Electromechanic - 1

Terms of work

The work is being done:

2.1. With stress relief

2.2. Alongside

Preparatory work and work permit

4.1. On the eve of the work, apply for the withdrawal of the trans for repair
formatter.

4.2. Check the serviceability and expiration dates of protective equipment, devices
ditch, prepare tools, mounting fixtures and materials.

4.3. After issuing an order to the work foreman, receive instructions from
the person who issued the order.

4.4. Operational personnel to prepare the workplace.
For the foreman to check the implementation of technical measures for
workplace preparation.

4.5. Get the team to work.

4.6. The foreman to instruct the members of the brigade and clearly
distribute responsibilities among them.

End of technological card No. 2.2.

Note. All operations with oil filled and 110-220 kV bushings must be carried out in cooperation with a RRU specialist.

Completion of work

Technological map No. 2.3. Current repair of autotransformers for voltage 110-220 kV

Cast

Electromechanic - 1

Traction substation electrician 4th category - 1

Traction substation electrician 3rd category - 1

Terms of work

The work is being done:

2.1. With stress relief

2.2. Alongside

3. Protective equipment, devices, tools, fixtures and materials:

Safety helmets, safety belt, ladder, grounding, shorts, dielectric gloves, megohmmeter for voltage 1000 and 2500 V, stopwatch, thermometer, level, pump with pressure gauge and hose, wrenches, combination pliers, screwdrivers, scraper, brushes, container for draining sediment, glass containers with a ground stopper for oil sampling, indicator silica gel, silica gel, transformer oil, TsIA-TIM lubricant, white spirit, moisture-oil-resistant varnish or enamel, spare oil-indicating glasses, rubber gaskets, cleaning material, rag

Technological map No. 2.4. Current repair of transformers with a capacity of 40 - 630 kV-A

Cast

Electromechanic - 1

Traction substation electrician 3rd category - 1

Terms of work

The work is being done:

2.1. With stress relief

2.2. Alongside

3. Protective equipment, devices, tools, fixtures and materials:

Safety helmets, safety belt, ladder, grounding, shorts, dielectric gloves, megohmmeter for voltage 1000 and 2500 V, stopwatch, thermometer, level, pump with pressure gauge and hose, wrenches, combination pliers, screwdrivers, scraper, brushes, container for draining sediment, glass containers with a ground stopper for oil sampling, indicator silica gel, silica gel, zeolite, transformer oil, CIATIM grease, white spirit, moisture-oil-resistant varnish or enamel, spare oil-indicating glasses, rubber gaskets, cleaning material, rag

Oil circuit breakers

Continuation of technological map No. 3.1.

Cast

Electromechanic - 1

Traction substation electrician 4 categories - 1 Traction substation electrician 3 categories - 1

Terms of work

The work is being done:

2.1. With stress relief

2.2. Alongside

3. Protective equipment, devices, tools, fixtures and materials:

Safety helmets, safety belt, ladder, grounding, short circuits, dielectric gloves, megohmmeter for voltage 1000 and 2500 V, electric stopwatch, spanners, combined pliers, screwdrivers, scraper, brushes, glass containers with a ground stopper for oil sampling, silica gel indicator, silica gel, transformer oil, CIATIM grease, white spirit, insulating varnish, spare oil-indicating glasses, rubber gaskets, cleaning material, rags

Cast

Electromechanic - 1

Traction substation electrician 3rd category - 1

Terms of work

The work is being done:

2.1. With stress relief

2.2. Alongside

3. Protective equipment, devices, tools, fixtures and materials:

Protective helmets, safety belt, ladder, grounding, short circuits, dielectric gloves, megohmmeter for voltage 1000 and 2500 V, LVI-100 test facility, electric stopwatch, wrenches, combined pliers, screwdrivers, scraper, brushes, transformer oil, CIATIM lubricant, white spirit, insulating varnish, spare oil-indicating glasses, rubber gaskets, cleaning material, rags

Completion of work

6.1. Collect instruments, tools, fixtures and materials.

6.2. Return to the switchboard traction substation.

6.3. Hand over the workplace to the admitting and close the outfit

6.4. Record the results of the measurements taken in a protocol.

Cast

Electromechanic - 1

Traction substation electrician 3rd category - 1

Terms of work

The work is being done:

2.1. With stress relief

2.2. Alongside

3. Protective equipment, devices, tools, fixtures and materials:

Protective helmets, grounding, short circuits, dielectric gloves, megohmmeter for voltage 1000 and 2500 V, electric stopwatch, wrenches, combination pliers, screwdrivers, scraper, transformer oil, TsIA-TIM grease, white spirit, insulating varnish, spare oil-indicating glasses, rubber pads, cleaning material, rags

Completion of work

6.1. Collect instruments, tools, fixtures and materials.

6.2. Return to the switchboard traction substation.

6.3. Hand over the workplace to the admitting and close the outfit

6.4. Record the results of the measurements taken in a protocol.

Cast

Electromechanic - 1

Traction substation electrician 4th category - 1

Terms of work

The work is being done:

2.1. With stress relief

2.2. Alongside

3. Protective equipment, devices, tools, fixtures and materials:

Megaohmmeter for voltage 500 and 2500 V, tester, electric soldering iron, vacuum cleaner, calibration wrench, spanners, combined pliers, screwdrivers, files, scraper, control lamp, hair brush, wooden ladder, ladder, white spirit, cleaning material, CIATIM lubricant

Completion of work

6.1. Collect instruments, tools, fixtures and materials.

6.2. Return to the switchboard traction substation.

6.3. Hand over the workplace to the admitting and close the outfit

6.4. Record the results of the measurements taken in a protocol.

Cast

Electromechanic - 1

Traction substation electrician 4th category - 1

Terms of work

The work is being done:

2.1. With stress relief

2.2. Alongside

3. Protective equipment, devices, tools, fixtures and materials:

Ohmmeter, portable lamp, vacuum cleaner, wrenches and socket wrenches, screwdrivers, ruler, caliper, files, scraper, wire brush, set of probes, files for cleaning switch contacts, wooden stick, sandpaper, white and carbon paper, white spirit, lubricant CIATIM, rags, cleaning material

Cast

Electromechanic - 1

Traction substation electrician 4th category - 1

Terms of work

The work is being done:

2.1. With stress relief

2.2. Alongside

3. Protective equipment, devices, tools, fixtures and materials:

Stopwatch, portable lamp, vacuum cleaner, wrenches and socket wrenches, screwdrivers, ruler, caliper, files, scraper, wire brush, set of probes, files for cleaning switch contacts, glass cloth, wooden stick, sandpaper, white and carbon paper, white spirit, TsIA-TIM lubricant, rags, cleaning material

Transformers Technological map No. 2.1.