Repair of power transformers. We carry out repairs of power transformers Technological map of current repairs of power transformers
TYPICAL TECHNOLOGICAL CARD
INSTALLATION OF POWER TRANSFORMERS WITH NATURAL OIL COOLING, VOLTAGE UP TO 35 kV, POWER UP TO 2500 kVA
1 AREA OF USE
A typical technological map has been developed for the installation of power transformers.
General information
Requirements for transportation, storage, as well as installation and commissioning of power transformers are determined by the instructions "Transportation, storage, installation and commissioning of power transformers with voltage up to 35 kV inclusive without revision of their active parts" and the technical guidelines "Power transformers, transportation , unloading, storage, installation and commissioning."
The power transformer, which arrived from the equipment supplier (manufacturer, intermediate base), is subjected to external inspection. During the inspection, they check the presence of all places on the railway bill of lading, the condition of the packaging, the absence of oil leaks at the joints of the radiators with the tank and at the sealing points, the integrity of the seals, etc.
The packaging of dry transformers must ensure their safety from mechanical damage and direct exposure to moisture.
If a malfunction or damage is detected, a report is drawn up and sent to the plant or intermediate base.
After inspection and acceptance of the transformer, they begin to unload it.
It is recommended to unload the transformer using an overhead or mobile crane or a stationary winch of appropriate lifting capacity. In the absence of lifting means, it is allowed to unload the transformer onto the sleeper cage using hydraulic jacks. Unloading of transformer components (coolers, radiators, filters, etc.) is carried out by a crane with a lifting capacity of 3 to 5 tons. When unloading transformers with lifting devices (crane, etc.), it is necessary to use inventory slings of the appropriate lifting capacity, which have factory marks and have passed tests .
To lift the transformer, there are special hooks on the walls of its tank, and eyelets (lifting rings) on the roof of the tank. Slinging of cables for large transformers is carried out only with hooks, for small and medium ones - with hooks or eyes. The clamps and lifting ropes used for lifting must be made of steel rope of a certain diameter corresponding to the mass of the transformer. To avoid cable breaks, wooden pads are placed under all sharp edges of bends.
The heavy transformer, which arrives disassembled, is unloaded using a heavy-duty railway crane. In the absence of such a crane, unloading is carried out using winches and jacks. To do this, the transformer tank, installed on a railway platform, is first lifted with two jacks using lifting brackets welded to the bottom and walls of the tank, then a trolley supplied separately from the tank is brought under the tank, and with the help of winches the tank is rolled off the platform onto a specially prepared sleeper stand. Rolling is carried out along steel strips placed under the rollers of the cart. The remaining components of the transformer (expansion tank, terminals, etc.) are unloaded with conventional cranes.
The unloaded transformer is transported to the installation site or to a workshop for inspection. Depending on the weight of the transformer, transportation is carried out by car or on a heavy-duty trailer. Transportation by drag or on a steel sheet is prohibited.
Vehicles used to transport transformers must have a horizontal loading platform that allows the transformer to be freely installed on it. When placing the transformer on a vehicle, the major axis of the transformer must coincide with the direction of travel. When installing a transformer on a vehicle, it is necessary to take into account the location of the inputs on the transformer to avoid subsequent rotation before installation at the substation.
Dismantled components and parts can be transported along with the transformer if the carrying capacity of the vehicle allows and if the requirements for transportation of the transformer itself and its components are not violated.
The carrying capacity of the vehicle must be no less than the mass of the transformer and its elements if they are transported together with the transformer. It is not allowed to apply traction, braking or any other types of forces to the transformer structural elements when transporting them.
Figure 1 shows a diagram of how to install a transformer on a car.
Fig.1. Diagram of installation and fastening of the transformer on the car
In some cases, before installation, transformers are stored for a long time in on-site warehouses. Storage must be organized and carried out in such a way as to exclude the possibility of mechanical damage to transformers and dampening of the insulation of their windings. Compliance with these requirements is ensured by certain storage conditions. Depending on the design and method of shipment of transformers, their storage conditions will be different. In all cases, it is necessary that the duration of storage of transformers does not exceed the maximum permissible established by the instructions mentioned above.
The storage conditions for power transformers with natural oil cooling are accepted according to the group of storage conditions OZHZ, i.e. in open areas.
The storage conditions for dry, unsealed transformers must comply with the conditions of group A, and for transformers with a non-flammable liquid dielectric - group OZh4. The storage conditions for spare parts (relays, fasteners, etc.) for all types of transformers must comply with condition group C.
Dry-type transformers must be stored in their own casings or original packaging and must be protected from direct exposure to precipitation. Oil transformers and transformers with liquid non-flammable dielectric must be stored in their own tanks, hermetically sealed with temporary (during transportation and storage) plugs and filled with oil or liquid dielectric.
When storing transformers up to 35 kV inclusive, transported with oil without conservators, installing the conservator and adding oil must be done as soon as possible, but no later than after 6 months. When storing transformers with a voltage of 110 kV and above, transported without an expander with or without oil, the installation of the expander, topping up and filling of oil should be carried out as soon as possible, but no later than 3 months from the date of arrival of the transformer. The oil must comply with the requirements of the PUE. The oil level must be periodically monitored (if the level drops, oil must be added); at least once every 3 months, an oil sample must be taken for a short analysis. The absence of oil leakage from the transformer tank is periodically checked by following marks on the tank and fittings. Sealed oil transformers and transformers with non-flammable liquid dielectric must be stored in the manufacturer's packaging and protected from direct exposure to precipitation.
2. ORGANIZATION AND TECHNOLOGY OF WORK EXECUTION
INSTALLATION OF POWER TRANSFORMERS WITH NATURAL OIL COOLING
The facilities mainly use power transformers with natural oil cooling, voltage up to 35 kV, power up to 2500 kVA. The scope of work for installing a power transformer with natural oil cooling depends on the form in which it arrives from the factory - assembled or partially disassembled. Regardless of the type of delivery, the sequence of installation operations will be the same.
When installing a power transformer, you must perform the following steps in sequence:
Accept the premises (installation site) and transformer for installation;
Inspect the transformer;
Dry the windings (if necessary);
Assemble and install the transformer in place.
Acceptance of premises (installation site) and transformer for installation
The room (open area) for installation of the transformer must be completely completed. Lifting devices or portals must be installed and tested before installation of the transformer.
As is known, the supply of power transformers and their delivery to the installation area must be carried out by the customer. When accepting transformers for installation and determining the possibility of further work, the entire range of issues related to transportation and storage, the condition of transformers by external inspection and determination of insulation characteristics, readiness and equipment of the room or installation site are considered.
The customer must provide the following necessary information and documents:
Date of dispatch of transformers from the manufacturer;
Conditions of transportation from the manufacturer (by rail or other transport, with or without oil, with or without an expander);
Certificate of acceptance of the transformer and components from the railway;
Scheme of unloading and transportation from the railway to the installation site;
Storage conditions for transformers and components (oil level in the transformer, period for filling and topping up oil, characteristics of the filled or topped up oil, results of transformer insulation assessment, oil sample testing, leak testing, etc.).
At the same time, the condition of the transformer is assessed by external inspection, the results of checking the tightness of the transformer and the condition of the indicator silica gel.
During an external inspection, they check for dents and the integrity of the seals on the taps and plugs of the transformer.
The transformer is checked for leaks before installation, before adding or adding oil. Before checking the tightness, tightening the seals is prohibited. The tightness of transformers transported with an expander is determined within the oil indicator marks.
The tightness of transformers transported with oil and a dismantled expander is checked by pressing an oil column 1.5 m high from the level of the cover for 3 hours. The transformer is considered tight if, during testing, no oil leaks are observed in places located above the level of the oil with which it arrived transformer. It is allowed to check the tightness of the transformer by creating an excess pressure of 0.15 kgf/cm (15 kPa) in the tank. The transformer is considered sealed if after 3 hours the pressure drops to no more than 0.13 kgf/cm (13 kPa). The tightness of transformers transported without oil and filled with dry air or inert gas is checked by creating an excess pressure of 0.25 kgf/cm (25 kPa) in the tank. The transformer is considered sealed if the pressure drops after 6 hours to no more than 0.21 kgf/cm (21 kPa) at an ambient temperature of 10-15 °C. Creation of excess pressure in the transformer tank is done by pumping dry air through a silica gel desiccant with a compressor or by supplying dry inert gas (nitrogen) from cylinders into the tank.
Acceptance of transformers for installation is documented in an act of the established form. Representatives of the customer, installation and commissioning (for transformers of size IV and above) organizations participate in the acceptance.
Audit
An inspection of power transformers is carried out before installation in order to check their condition, identify and timely eliminate possible defects and damage. The inspection can be carried out without inspecting the removable (active) part or with inspecting it. All transformers to be installed are subject to inspection without inspection of the removable part. An audit with inspection of the removable part is carried out in cases where damage to the transformer is detected, which gives rise to assumptions about the presence of internal faults.
Transformers currently produced have additional devices that protect their removable part from damage during transportation. This makes it possible, subject to certain storage and transportation conditions, not to carry out a labor-intensive and expensive operation - inspection with lifting of the removable part. The decision to install transformers without revising the removable part should be made based on the requirements of the instructions “Transportation, storage, installation and commissioning of power transformers for voltages up to 35 kV inclusive without revision of their active parts” and “Power transformers. Transportation, unloading, storage, installation and commissioning." At the same time, a comprehensive assessment of compliance with the requirements of the instructions is carried out with the preparation of appropriate protocols. If the requirements of the instructions are not met or faults are detected during an external inspection that cannot be eliminated without opening the tank, the transformer is subject to inspection with inspection of the removable part.
When conducting an audit without inspecting the removable part, a thorough external inspection of the transformer is carried out, an oil sample is taken to test for electrical strength and chemical analysis; measure the insulation resistance of the windings.
During the inspection, they check the condition of the insulators, make sure that there are no oil leaks at the seals and through the welds, and that there is the required oil level in the conservator.
The electrical strength of the oil, determined in a standard vessel, should not be less than 25 kV for devices with higher voltages up to 15 kV inclusive, 30 kV for devices up to 35 kV and 40 kV for devices with voltages from 110 to 220 kV inclusive.
Chemical analysis of transformer oil is carried out in a special laboratory, and the compliance of the chemical composition of the oil with GOST requirements is determined.
The insulation resistance of the windings is measured with a megohmmeter for a voltage of 2500 V. The insulation resistance is measured between the high and low voltage windings, between each winding and the housing. For oil transformers with higher voltage up to 35 kV inclusive and power up to 6300 kVA inclusive, insulation resistance values measured at the sixtieth second () must be at least 450 MOhm at a temperature of +10 °C, 300 MOhm at +20 °C, 200 MOhm at +30 °C, 130 MOhm at +40 °C. The value of the absorption coefficient should be at least 1.3 for transformers with a power up to 6300 kVA inclusive.
The physical essence of the absorption coefficient is as follows. The nature of the change in the measured value of the winding insulation resistance over time depends on its condition, in particular on the degree of humidification. To understand the essence of this phenomenon, we will use an equivalent circuit for winding insulation.
Figure 2 shows the insulation resistance measurement circuit and the equivalent circuit. In the process of measuring insulation resistance using a megohmmeter, DC voltage is applied to the winding insulation. The drier the winding insulation, the greater will be the capacitance of the capacitor formed by the winding conductors and the transformer body, and therefore, the greater the charge current of this capacitor will flow in the initial period of measurement (at the fifteenth second from the moment the voltage is applied) and the megohmmeter readings will be smaller ( ).
In the subsequent measurement period (at the sixtieth second), the capacitor charge ends, the charge current decreases, and the megohmmeter reading increases () .
The drier the insulation of the windings is, the greater the difference in megohmmeter readings will be in the initial () and final () measurement periods and, conversely, the wetter the insulation of the transformer windings is, the smaller the difference in these readings will be. 
6. TECHNICAL AND ECONOMIC INDICATORS
State estimate standards.
Federal unit prices for equipment installation.
Part 8. Electrical installations
FERM 81-03-08-2001
Order of the Ministry of Regional Development of Russia dated August 4, 2009 N 321
Table 08-01-001. Power transformers and autotransformers
Meter: pcs.
| Pricing code | Name and technical characteristics of equipment or types of installation | Direct costs, rub. | Including, rub. | Labor costs of workers - installers, person-hours |
|||
| Remuneration of workers - installers | machine operation | math rials | |||||
| Total | incl. wages for workers operating a machine | ||||||
| Three-phase transformer: |
|||||||
| 08-01-001-06 | 35 kV power 2500 kVA | 7018,51 | 2635,88 | 3748,71 | 360,72 | 633,92 | 274 |
BIBLIOGRAPHY
SNiP 3.03.01-87. Load-bearing and enclosing structures.
SNiP 12-03-2001. Occupational safety in construction. Part 1. General requirements.
SNiP 12-04-2002. Occupational safety in construction. Part 2. Construction production.
GOST 12.2.003-91. SSBT. Production equipment. General safety requirements.
GOST 12.3.009-76. SSBT. Loading and unloading works. General safety requirements.
GOST 12.3.033-84. SSBT. Construction machines. General safety requirements for operation.
GOST 24258-88. Scaffolding means. General technical conditions.
PPB 01-03. Fire safety rules in the Russian Federation.
The electronic text of the document was prepared by Kodeks JSC
and verified according to the author's material.
Author: Demyanov A.A. - Ph.D., teacher
Military Engineering and Technical University,
St. Petersburg, 2009
Removing the transformer from the electric locomotive (the work is done after removing the small removable roof and cooling fans of the traction transformer)
1.1 Disconnect all shunts and busbars from the traction transformer, step changer and instrument cabinet.
1.2 Disconnect cables and low-voltage wires from the substation and the instrument cabinet, having first checked their markings. If there is no marking - restore, if marking is incorrect - re-mark.
1.3 Unscrew the bolts securing the transformer to the electric locomotive body frame. Remove the mesh fencing.
1.4 Moor the traction transformer with a 30-ton bridge crane and move it to the transformer compartment on a transport trolley
Preliminary tests of the transformer.
2.1 Install the transformer in the test station
2.2 Measure the insulation resistance of all windings in accordance with clause 11.2.1.
2.3 Measure the ohmic resistance of the windings in accordance with clause 11.2.2.
2.4 Test the electrical strength of the insulation of the windings in accordance with clause 11.2.4.
2.5 Perform experiment x.x. similar to clause 11.2.6.: at a voltage of 62.5 V, losses should be no more than 2.3 kW.
During testing, identify possible malfunctions and determine the scope of repairs. If necessary, repair the active part.
Disassembling the traction transformer.
3.1 Install the transformer to the repair position
3.2 Clean the traction transformer from dirt and dust.
3.3 Drain the oil from the traction transformer, step changer and expansion tank.
3.3 Remove the substation, instrument cabinet and oil pumps from the transformer and submit them for repair.
3.4 Remove the BF50/10 gas relay, air dryer, flow indicators, thermostats and expansion tank from the transformer.
3.5 Remove the separating plate.
3.6.Remove the covers of the assembly hatches, disconnect the current transformers and bushings.
3.7 Remove inputs m1-m4.
3.8 Unscrew the bolts securing the bell to the transformer tank.
3.9 Moor with an overhead crane and remove the bell.
3.10. Remove the cooling system.
Repair of the active part of the transformer (magnetic core and windings).
4.1 Check the insulation condition of the accessible turns of the coils, leads, contamination of the surfaces of the windings, magnetic circuit and leads with oil deposits, as well as the dimensions of the cooling channels.
4.2 Check the condition of the fastening, wedging and compression of the windings, the condition and fastening of the insulating gaskets between the coils, the serviceability of the electrical connections, the absence of signs of overheating, overlaps, the absence of deformations and displacements of the coils and gaskets.
4.3 Restore loose fastening of the windings by tightening the pressure bolts or installing wedging inserts made of getinax between the pressure plate and the yoke sheets. Tighten the pressure bolts with a torque wrench with a torque of 12-13 kg/cm. After tightening, secure the bolts with wire.
4.4 Tighten the bolts at the bottom of the tie frame on both sides of the bottom of the tank. If necessary, install a fiberglass gasket between the clamping frame and the magnetic core. The tightening torque of the bolts should be 5-6 kg/cm.
4.5 If there are no breaks, interturn short circuits and satisfactory insulation resistance relative to the housing and other windings, bulging winding coils can be returned to their original position by light blows of a hammer through a wooden spacer.
4.6 Check the insulation resistance of the tie rods in relation to the magnetic circuit with a 1000 V megger.
4.7. Check the serviceability of the grounding of the magnetic core, the serviceability of the fastening of the grounding shunt between the sheets of the magnetic circuit, the absence of traces of heating and melting of the shunt and the iron of the magnetic core.
4.8 Clean the contacts of the 25/12 kV switch, check their pressing and fit, check the fastening of the cables, set the switch to the “25 kV” position.
4.9 Clean the insulating plates of the autotransformer terminals and secondary windings of the transformer from dirt, degrease, inspect, and replace defective ones.
4.10 Inspect current transformers, check fastening, integrity of windings, absence of cracks, melting and other damage.
4.11 Dismantle the inlets on the tank cover, clean, inspect, and replace the seals. Replace bushings with cracks. It is allowed to repair bushings D25, D1 type Kkr37/63O using the manufacturer’s technology in accordance with the Rules for the care of the transformer set.
4.12 Remove oil deposits from the surfaces of the windings, leads, magnetic circuit and cooling channels. The use of wooden scrapers is allowed. Flush the transformer with clean, dry transformer oil.
4.13 Clean the transformer tank, conservator and cooling system from sludge and sediment, rinse with clean, warm, dry transformer oil. Clean the outer part of the coolers from dust and dirt, degrease with gasoline.
4.14 Inspect the inner walls of the tank and its roof, check the color strength of the inner surface. Clean areas with peeling paint and paint with epoxy primer paint. Check the condition of the welding of the installation chambers inside the tank for installing the magnetic rod, the serviceability of the felt gaskets under the legs of the magnetic rod, and the devices for attaching the core to the tank.
4.15 Check the condition of the oil pipelines, their valves, taps and seals; replace or repair defective ones. Inspect welds, cut out defective ones and restore them.
4.16 The active part of the transformer must be exposed to air for no more than 24 hours at an air humidity of no more than 75%.
Repair of transformer cooling radiators.
5.1 Prepare radiators for testing. Install clamps to prevent deformation. Assemble the flange for compressed air supply. Close the opposite flange tightly.
5.2 Connect the pressure hose with pressure reducing valve to the radiator flange.
5.3 Immerse the radiators in a tank of water heated to 60 0 C.
5.4 Test radiators with an air pressure of 2.5 atm.
5.5 On serviceable radiators, dismantle the testing devices. Wash the radiators with transformer oil and transfer them for assembly.
5.6 Remove the faulty radiator from the radiator set. Install a blank flange on the radiator. Immerse the radiator in a tank of water heated to 60 0 C and test individual pipes with an air pressure of 2.5 atm. Mark the places of defects. Remove the radiator from the device and seal the defective pipes tightly on both sides with tin. No more than 5% of the tubes are allowed to be embedded in one radiator.
5.7 After repair, assemble a set of radiators and repeat tests in paragraphs 5.1.-5.5.
Drying of transformer windings is carried out when the insulation resistance of the windings is below the standardized values or when the active part is exposed to air for more than 24 hours.
6.1 Move the transformer to a drying cabinet.
6.2 Turn on the cabinet heating and, with the cabinet lid slightly open, heat the transformer to a temperature of 85-95 0 C with a temperature increase rate of no more than 60 0 C/hour.
The temperature is controlled by thermoelements installed at 2 points: on one of the coils at the top between the insulation collars and on the plate for the magnetic core tie.
6.3 After the transformer temperature reaches 85-95 0 C, close the cabinet and dry the transformer in a vacuum. Vacuum increase no more than 0.25 atm/hour (0.025 MPa/hour).
After reaching a vacuum of 0.00665-0.000133 atm. (665-13.3 Pa) dry for 28 hours. at a temperature of 85-95 C.
With TR-3, drying in a vacuum of at least 5320 Pa (0.0532 atm) is allowed.
6.4 The end of drying is the moment when the insulation resistance of the windings exceeds the standardized values and practically stops increasing. The condensate output should be no more than 0.5 l/hour.
6.5. Upon completion of drying, stop heating and eliminate the vacuum at a rate of no more than 0.01875 MPa/hour (0.1875 atm/hour).
6.6 After drying, tighten the fastening of the windings with pressure bolts to a torque of 12-13 kgf/m, if necessary, place a gasket made of getinax between the pressure plate and the magnetic core. Tighten and cotter the connecting bolts, tubes, and holders.
6.7 Check the condition of the insulation of the magnetic core tie rods with a 1000 V megger.
6.8 Move the transformer to the tank for assembly.
6.9 With TR-3, it is allowed to dry the transformer in its own tank by short-circuiting the traction winding. Short-circuit current should not be more than half the rated current of the traction winding.
Transformer assembly.
7.1 Check the insulation resistance of the windings relative to each other and relative to the housing:
high-voltage winding (Do, D1, D25) - 100 MOhm;
traction windings (m1-m4) - 20 MOhm;
heating winding (C1-C2) - 10 MOhm;
auxiliary winding (E-J) - 5 MOhm.
7.2 Assemble the tank: cooling system, bushings, insulating plates, step switch, 25/12.5 switch, current transformers, assembly hole covers, expansion tank.
When assembling, install new seals made of oil-resistant rubber.
7.3 Fill the transformer with oil.
Open the topmost air vent. Fill the tank from the bottom with dry, warm transformer oil, heated to 70 0 C. The temperature of the transformer should be within 60-70 0 C (measure the temperature on the magnetic circuit before assembling the upper part of the tank). Close the air bleeder hole.
When the transformer temperature is less than 60 0 C, it is necessary to preheat the transformer by circulating warm oil between the transformer and the filtering device until the temperature of the transformer and oil is equalized. For heating, set the circulation speed to 450-600 l/hour for 7 hours.
7.4 After installing the BF50/10 gas relay and air dryer, top up the transformer with oil through the expansion tank.
7.5 Bleed air from the tank at 12 points.
7.6 Pump the oil with pumps for 2 hours, then bleed the air again at 12 points.
7.7 Leave the transformer for 2 days, then bleed off the air at 12 points.
Air dryer repair.
8.1 Disassemble the air dryer removed from the transformer.
8.2 Inspect the air dryer parts and replace those that are unsuitable.
8.3 Regenerate drying agent.
Pour the drying agent into a clean lining in a layer of no more than 10 mm.
Heat the drying agent in the drying chamber and dry at a temperature of 120-180 0 C for 3 hours.
The end of drying is a change in color from pink to bright blue.
Brown color indicates the destruction of drying properties as a result of overheating.
The drying agent can be regenerated up to 50 times
8.4 Assemble the air dryer. The oil seal must be transparent.
Fill the air dryer space with a mixture of 80% silica gel (white) and 20% blaugel (bright blue).
8.5.Install the air dryer on the expansion tank and fill the oil seal of the air dryer with transformer oil to the level indicated by the mark on the oil seal.
Repair of gas relay BF50/10/
9.1. To remove the relay from the transformer, after draining the oil from the transformer, unscrew the release bolt at the bottom of the relay housing and release the oil, disconnect the control circuit wires from the terminal strip, disconnect the grounding shunt and remove the relay.
9.2 Remove the internal mechanism from the housing, carefully inspect it, eliminate defects, and assemble the relay.
9.3 Test the electrical strength of the insulation of the relay electrical circuits relative to the housing with and without transformer oil.
The test is carried out with an alternating voltage of 2.5 kV with a frequency of 50 Hz for 5 seconds.
9.4 Check the relay for leaks.
Carry out the check within 20 minutes. With an excess oil pressure of 1 kgf/cm2, there should be no drop in oil pressure observed on the bench pressure gauge, and there should be no oil leakage from the relay.
9.5 Perform a functional test of the relay.
9.5.1 Perform triple control of the action using the control button on the oil-filled relay.
In this case, the stand's signal lamp should light up.
9.5.2 Check the relay operation when the oil level drops.
Inflate air through the control valve. In this case, the stand signal lamp should light up.
Drain the oil from the relay. In this case, two signal lamps of the stand should light up.
9.6 Test results according to paragraphs 9.3.-9.5. enter into the journal.
9.7 Place a working relay on the transformer and connect the control circuit wires to the terminal strip in accordance with the diagram.
Testing thermostats.
10.1 Install the thermostat in a bath with transformer oil heated to 60-80 0 C and a control thermometer placed in it.
10.2 Set the thermostat to the maximum temperature (110 0 C).
10.3 Connect the electrical circuit for signaling the thermostat on to terminals 1.3 of the thermostat.
10.4.Smoothly reduce the temperature of the thermostat setting until the alarm is triggered to turn on the thermostat.
10.5. Compare the readings of the control thermometer with the readings of the thermostat scale.
10.6. If the readings of the thermostat and the control thermometer coincide, install the thermostat on the transformer tank.
10.7 If the readings do not match, adjust the thermostat.
Using a screwdriver, secure the adjusting shaft. Unscrew the installation bolt. While holding the axis, set the scale with the mark to the actual temperature at which the thermostat was supposed to operate. Secure the installation bolt.
10.8 After adjustment, test the thermostat again according to paragraphs 10.1.-10.5.
10.9 Connect control circuit wires to the thermostat terminals according to the electrical diagram.
10.10 Adjust the thermostat settings:
01513 - setpoint 80 0 C;
01525 - setpoint 40 0 C;
01526 — setpoint 60 0 C;
01529 - setpoint 20 0 C.
Traction transformer testing.
Transformer testing after SR.
Transformer testing after TR-3.
11.1 Preparatory operations.
11.1.1 Ground the transformer housing.
11.1.2 Turn on the oil pumps and pump the oil for 2 hours.
Let the oil settle for 12 hours.
11.1.3 Carry out an oil analysis in accordance with the Instructions for the use of lubricants on locomotives and MVPS TsT-2635.
11.1.4 Bleed air from insulators, radiators, gas relay, voltage switch.
11.1.5 Check the operation of the PS oil filtration pump and the PS oil heating system.
11.1.6 Check the polarity of the current transformers for protecting the high voltage winding and the correctness of the circuit in the terminal box. Ring the current transformers of the traction windings and heating windings.
11.1.7 Short-circuit and ground all current transformers.
11.2.1 Measure the insulation resistance of all windings relative to the housing and relative to each other with a 2500 V megger.
The insulation resistance must be no less than:
- high-voltage winding - 100 MOhm;
- heating winding - 10 MOhm;
- traction windings - 20 MOhm;
- auxiliary winding - 5 MOhm.
Determine the absorption coefficient (moisture content of the windings)
K = R60 / R15 > 1,
When the measurement temperature is above 15 0 C, recalculate by multiplying the readings by the coefficient from the table
| Temperature difference | 5 0 C | 10 0 C | 15 0 C | 20 0 C | 25 0 C | 30 0 C |
| Coefficient | 1,23 | 1,5 | 1,64 | 2,25 | 2,75 | 3,4 |
11.2.2 Measure the ohmic resistance of the windings using a voltmeter-ammeter method or a DC bridge.
Check the resistance of the autotransformer winding at all positions.
Resistance values should not differ from the nominal values by more than 10%.
Nominal values of winding resistance, MOhm
| m1-m2 | m3-m4 | E-J | E-H | E-G | E-F | C1-C2 | Do-D25 | Do-D1 |
| 1,6 | 1,6 | 1,1 | 0,8 | 0,66 | 0,42 | 46 | 492 | 460 |
Autotransformer winding resistance by position, mOhm
| Pos. | Resistance | Pos. | Resistance | Pos. | Resistance | Pos. | Resistance |
| Do-1 | 19,2 | Do-9 | 98,4 | Do-17 | 210,0 | Do-25 | 364,0 |
Resistance of autotransformer winding coils, Ohm
| Cat. | Resistance | Cat. | Resistance | Cat. | Resistance | Cat. | Resistance |
| 1 | 0,0182 | 4 | 0,0080 | 7 | 0,0086 | 10 | 0,0104 |
At an ambient temperature different from 15 0 C, it is necessary to bring the resistance to 15 0 C according to the formula:
R 15 = R env – , where
R ambient - winding resistance at ambient temperature
environment, Ohm;
t ambient - ambient temperature, 0 C.
11.2.3 Checking the transformation ratio.
Apply high voltage to the winding by placing a Do-PS jumper, voltage 200 V.
Make voltage measurements at all positions of the autotransformer winding and on all other windings with the PS position at 32 positions.
The voltage values must correspond to those indicated in the table
| conclusions | Do-D | m1-m2 | m3-m4 | C1-C2 | E-F | E-G | E-H | E-J |
| Voltage, V | 200 | 8,3 | 8,3 | 24,7 | 1,1 | 1,8 | 2,1 | 2,8 |
| NN | For example, B | NN | For example, B | NN | For example, B | NN | For example, B |
| 1 | 7,4 | 9 | 42,8 | 17 | 82,3 | 25 | 142,8 |
11.2.4 Testing the electrical strength of the insulation of the windings relative to each other and relative to the housing with a voltage of 50 Hz for 1 min.
Test voltage values:
- HV winding 25 kV (Do, D1, D25) - 52.5 kV;
- heating winding (C1, C2) - 11.2 kV;
- traction windings (m1-m2,m3-m4) - 4.9 kV;
- auxiliary winding (E-J) - 1.54 kV.
The test voltage is applied between the short-circuited winding under test and a grounded tank to which all other short-circuited windings of the transformer are connected.
The transformer is considered to have passed the test if during the tests no breakdown or partial discharges were observed, determined by sound, gas, smoke or instrument readings.
11.2.5 Testing the electrical strength of insulation by induced voltage with double rated voltage of increased frequency 200 Hz for 30 seconds. The test checks the turn insulation of the transformer windings.
A voltage of 2080 V is supplied to terminals m3-m4 of the traction winding, the remaining windings are open, while one terminal of each winding (Do, E, C1, m1) is grounded.
The transformer is considered to have passed the test if no current surges or smoke emission from the expander were observed during the tests.
11.2.6 Idling experience.
Measure losses and no-load current, while checking the condition of the transformer magnetic system. Apply the rated voltage to winding m3-m4, and then 115% of the rated voltage with a frequency of 50 Hz. All
the remaining windings are open, one terminal of each winding is grounded.
The following values of losses and current x.x are allowed.
Uxx=1040 V Ixx=90-120 A Pxx=94-125 kW
Uxx=1200 V Ixx=100-140 A Pxx=120-168 kW
11.2.7 Short circuit experience.
Apply a voltage of 200 V with a frequency of 50 Hz to the Do-D25 winding. The low voltage windings are short-circuited one by one, and the current, voltage and short-circuit power are measured.
Measured short-circuit losses convert to nominal values:
Rn=Rizm*K1*K2, where
Riz - measured short-circuit losses, kW;
K1=Un/Umeas—voltage conversion factor;
K2=In/Imeas – current conversion factor.
By comparing the measured values, reduced to the nominal mode, with the permissible ones, check the correctness of the windings.
When short-circuiting the traction windings, simultaneously check the current transformers protecting the traction windings. If the heating winding is short-circuited, check the heating winding protection current transformers.
| Shorted pins | Transf.current terminals | K=Irev/Itransf |
| m1-m2 | 836-837 | 80 |
11.2.8 Check the insulation resistance of all windings as in paragraph 11.2.1.
11.3.1 Measurement of winding insulation resistance according to clause 11.2.1.
11.3.2 Measurement of ohmic resistance of windings according to clause 11.2.2.
11.3.3 Testing the electrical strength of winding insulation in accordance with clause 11.2.4.
11.3.4 Idling experience according to clause 11.2.6.
Painting the external surfaces of the transformer.
12.1 Paint the cooling system with yellow PF-115 enamel at least 2 times.
12.2 Paint the transformer with PF-115 gray enamel at least 2 times.
12.3 Paint the underbody part of the transformer with black enamel.
Handing over the transformer to the locomotive receiver.
13.1 Fill out the transformer test report.
13.2 Together with the workshop foreman, present the transformer for delivery to the locomotive receiver.
Including reconstruction (changes in structural elements) and modernization (changes in rated voltages and powers).
produced by the Khmelnitsky plant PJSC (Ukrelectroapparat) with a manufacturer's guarantee.
Supply voltage: 6 kV, 10 kV, 35 kV, non-standard.
Output voltage: 0.23 kV, 0.4 kV, 0.5 kV, 0.66 kV, non-standard.
We always fulfill our obligations, so our Customers can count on a decent level of service and quality work done.
) on open switchgears, when drawing up construction organization projects (COP) and electrical installation work projects (PPER).
Current transformers of the TFZM and TFRM series (single-phase, electromagnetic, oil, outdoor installation, support type) are designed to transmit information signals to measuring instruments, protection and control devices in alternating current installations.
Current transformers (hereinafter referred to as "transformers"") TFZM 500 B and TFRM 750 A are made in the form of two stages (lower and upper), the rest are single-stage. Transformers 220 - 750 kV have a screen on the expander, and two-stage transformers, in addition, have an additional screen covering the joint of the stages.
The technological map contains instructions for organitions and installation technologies, a list of mechanisms, tools, information on material costs, calculation of labor costs and work schedules.
The map assumes that work related to the installation of transformers is carried out directly at the installation site, at the place where they are installed, etc.
All calculated indicators in the map are given for the installation of one group (three phases) of transformers.
Labor costs for setup work, installation schedules andcalculations are not taken into account.
The technological map was developed in accordance with the “Guidelines for the development of standard technological maps in construction”. M., TsNIIOMTP Gosstroy USSR, 1987.
Prohibits to open transformers and take oil samples.
Installation should be carried out with the participation of the chief engineer of the manufacturer.
Technical criteria and controls for operations and processes are given in Table. . Acceptance inspection of mounted transformers is carried out in accordance with SNiP 3.05.06-85. When accepting work, they present documentation in accordance with the list of appendices. .