1. Purpose of compilation

This work guide is applied to the installation and live test of dry-type transformers in the construction of 10kV power distribution room.

2. Preparation basis

2.1 “Standards for Quality Inspection and Evaluation of Thermal Power Construction” for electrical installations;

2.2 SCB10 series dry-type transformer product instruction manual;

2.3 “Safety Work Rules for Electric Power Construction”;

2.4 Construction design drawings of this project (electric volume);

2.5 “Technical Specifications for Construction and Acceptance of Electric Power Construction”

3. Construction content and operation flow chart

Low-voltage desulfurization transformer inspection, drying, body installation and transformer accessories installation, live test run.

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4. Construction conditions

4.1 Staffing:

4.2 Conditions to be met

4.2.1 The civil work has been completed, the site is cleaned up, and the ground elevation is marked on the wall.

4.2.2 The work instructions have been compiled and approved.

4.2.3 The technicians organize the construction personnel to be familiar with the construction drawings and technical data, and make a technical disclosure, and the safety disclosure has been completed.

4.2.4 The transformer has been delivered to the site.

4.2.5 Carry out unpacking inspection and acceptance together with relevant departments, and make records.

5. Construction procedures and methods

5.1 Construction procedure:

Construction preparation Foundation channel steel production and installation Transformer secondary transportation Transformer unpacking inspection Transformer in place Bus bridge installation Bus connection Inspection of transformer after installation.

5.2 Construction method

5.2.1 Production of basic section steel.

5.2.2 Receive #8 channel steel as the basic section steel according to the design specification.

5.2.3 Put the channel steel on the horizontal platform and use a sledgehammer to straighten it. After inspection, the unevenness and straightness per meter are less than 1.5mm.

5.2.4 Use a toothless saw to cut the material according to the design size, and use a grinder or file to clean the burrs at the saw edge to make it smooth.

5.2.5 Assemble the profiled steel frame, use a steel tape measure to detect the diagonal error of the profiled steel frame is not less than 5mm, use a level to detect the straightness and unevenness of the profiled steel (not more than 1.5mm per meter, and not more than 5mm in total length). After they are basically qualified, they are welded together, re-inspected again, and welded firmly after passing.

5.2.6 Use an iron brush to remove the rust on the section steel, and then apply a layer of red lead paint for anticorrosion after revealing the metallic luster, and then apply a finish paint that is the same or similar to the color of the equipment.

5.3 Basic section steel installation

5.3.1 Contact the pre-embedded parts of the civil engineering cleaning department, and mark the final indoor floor elevation at the same time, and install the basic steel according to the transformer layout drawing issued by the design institute.

5.3.2 With the center line of the building as the parallel line, find the base steel installation datum line (the error is not greater than 5mm), take the final indoor floor elevation as marked by the civil engineering plus 5mm as the upper plane datum of the basic steel, and use a spirit level or U-shaped After the pipe level method is qualified, the welding is firm. At both ends of the plate foundation with busbar bridge, attention should be paid to the spacing and parallelism of channel steel between each other. The embedding of foundation channel steel shall comply with the regulations.

5.3.3 Weld 8 pieces of hot-dip galvanized round steel or -40×6 hot-dip galvanized flat steel at both ends of the foundation, and connect with the main grounding grid. Twice the width; small openable doors equipped with electrical appliances shall be reliably grounded with bare copper flexible wires and grounded metal frames.

5.3.4 All welds shall be repainted after removing the coating.

5.4 Transformer unpacking inspection

5.4.1 When opening the box for inspection, relevant personnel should be present.

5.4.2 First check whether the packaging is complete and undamaged, open the box and check and count. The specifications, models, and quantities of transformers and low-voltage panels should meet the design requirements. Accessories and spare parts should be complete. Records should be kept for unpacking inspection, quality problems should be raised in time, and records for unpacking inspection should be made.

5.5 Secondary transportation of transformers

5.5.1 Before transportation, check the type and quantity of the transformer.

5.5.2 The transformer is transported by car, there should be no serious impact and vibration during transportation, and it should be fixed firmly during transportation to ensure safety.

5.5.3 In the process of transportation, special personnel should be supervised to prevent tilting.

5.5.4 When the transformer is unloaded, it should be unloaded directly on the pre-placed roller bars. The direction of the transformer should be placed in consideration of the installation direction, and the transformer should be prevented from sliding when placing the transformer.

5.5.5 When the shell of the dry-type transformer can be disassembled, the shell should be dismantled first. When dismantling, it should be marked to avoid wrong installation. When dismantling, the observation window glass should be prevented from being damaged.

5.5.6 When the transformer is towed, protective measures should be taken, such as laying rubber skins, to prevent damage to the ground. Care should be taken to prevent touching the insulated windings when hauling.

5.5.7 The force during dragging should be uniform, consistent and coordinated, and the dragging should be slow to prevent tilting.

5.5.8 Construction should be carried out under unified command, pay attention to safety, and prevent hands and feet from being crushed by rolling bars.

5.6 Installation of dry-type transformer

5.6.1 Remove the packing box of the dry-type transformer, hang it on the roller bar, and slowly push it to the side of the channel steel foundation. If necessary, it can be pulled by a hoist on the lock frame at the lower 1/3 of the transformer.

5.6.2 When the dry-type transformer is directly fixed on the section steel, use a three-legged pole and a hoist to lift the transformer into place, use a spirit level, a plumb line, and a steel ruler to measure the deviation in position, and use the method of padding to reduce the deviation to within the excellent range. Use electric welding between the thin iron sheets and between the thin iron and the basic steel, and make corresponding marks on the transformer base. Generally, there should be no more than 3 gaskets, and the gaskets should not be exposed outside the base.

5.6.3 Use a marking pen to mark the corresponding position of the fixing hole of the base, remove the transformer, use an aircraft drill to drill 11 holes at the marked place, and use an M12 tap to tap the hole, the transformer is in place here, and after alignment, use an M12X40 plating Zinc bolts are fastened after passing through 12 square inclined washers.

5.6.4 When the transformer is installed in the protective cover, first fix the protective cover according to the vertical plate method, then use the tripod pole to lift the transformer installation rollers, and adjust the direction of the high and low sides (if there is no design, it is convenient for the low-voltage side busbar and incoming line cabinet) Inner busbar docking shall prevail), set traction stress in front of the protective cover door, the highest point of the stress is flush with the edge of the inner track of the protective cover, push it into the transformer track, adjust the center of gravity of the transformer so that it coincides with the center of the protective cover, and clamp the bolt with a stopper Connected to the track to make the roller brake reliably.

5.6.5 Send the meter to the meter calibration room for inspection, and fix it to the designated place on the transformer body after passing the test. The installation is level and firm.

5.6.6 The iron components of the upper shell of the dry-type transformer body and the grounding point of the iron core are made of multi-strand copper core wires with a cross-section of 1x50mm2 or more. After pressing tinned copper noses at both ends, they are screwed to the grounded flat iron, and the joints are coated with electric compound grease. The neutral point of the dry-type transformer should be connected to the main grounding network according to the design requirements after passing through the zero-sequence current transformer.

5.6.7 Use galvanized fasteners, the loose parts should be fastened, and the exposed length of the screw teeth should be 3 to 5 buttons.

5.6.8 Carry out the test according to the electrical handover test specification.

5.6.9 After the transformer is in place, do not fix it by welding, and weld together after the low-voltage plate is in place. After the transformer is in place, install the enclosure correctly according to the markings.

6. Quality technical requirements

6.1 After the foundation channel steel is installed, its top should be 10mm higher than the troweled ground, and the non-straightness and levelness of the foundation should be tested. The full length deviation is less than 5mm.

6.2 When the panels are installed, the level error of the tops of two adjacent panels is less than 1 mm, and the top of the arrayed panels is less than 5 mm. The vertical error should not be greater than 1.5/1000H of its height (H is the disk height). The unevenness of the disks arranged in a row is within 5 mm, and the joint between the disks is less than 2 mm.

6.3 The bolts, nuts and washers used to connect and fix the panel shall be galvanized parts, the paint of the panel shall be intact, the surface of the panel shall be consistent, and the arrangement shall be neat.

6.4 The connection of the bus bar should be good, and the insulating support and installation parts should be firm and reliable.

6.5 The distance between the secondary electrified body and the elevator to the ground is not less than 4 mm, and the surface leakage distance is not less than 6 mm.

6.6 1000V megohmmeter to check the bus insulation, it should be greater than 0.5 megohm.

6.7 All equipment marks, phase color marks, and circuit name marks should be clear and not easy to decolorize.

6.8 For the equipment that will not be put into operation immediately after installation, protective measures should be taken to prevent dust and moisture.

7. Precautions for safe construction

7.1 The insulation performance of electric tools should be inspected before use, there should be no leakage, and the shell should be reliably grounded.

7.2 Do not wear gloves when using electric drills.

7.3 Protective measures should be taken to transport the transformer, the transport should be slow to prevent excessive impact, and the crane should use a hydraulic crane with good performance.

7.4 There should be sufficient lighting in the workplace, and the warning signs should be hung up, and a certain number of fire extinguishers should be equipped.

7.5 Construction personnel entering the construction site must wear qualified labor protection clothing and safety helmets correctly. It is strictly forbidden to enter the construction site after drinking. After the daily construction, the work should be completed, the materials should be clean, and the site should be clean.

7.6 Special attention should be paid during the whole construction process, and the lead-out bushing and other accessories should not be damaged.

7.7 Organize construction personnel to study the measures and construction acceptance specifications before construction, and illegal operations are strictly prohibited.

7.8 Before the live test operation of the transformer, the secondary circuit should be checked to ensure the accuracy of the secondary circuit.

7.9 Before the installation of the panel cabinet, the indoor civil work is completed to meet the requirements of rainproof, moisture-proof, anti-corrosion, and dust-proof. If necessary, take measures to build a cover to prevent damage to the panel cabinet.

7.10 During the transportation of the panel, it should be commanded by professional lifting personnel.

7.11 After unpacking the cabinet, pay attention to clean it in time to prevent the passage from being blocked or the nails from getting stuck.

7.12 When the panel is pried into place, the manpower should be sufficient, and the command should be unified to prevent injury from falling over, and prevent crushing injuries in narrow places.

7.13 When moving the panel, care should be taken to prevent damage to the components and paint on the panel.

7.14 When padding the bottom of the pan, do not put your hands into the bottom of the pan. When the single-sided pans are installed side by side, you should prevent your hands from being squeezed when leaning against the pan.

7.15 When the panel is fixed, pay attention to the wooden block when hitting the panel with a hand hammer.

7.16 After the panel cabinet is installed, lock the panel door in time, and cover it with plastic cloth if construction will not be carried out in a short period of time to prevent secondary pollution.

7.17 After the cabinets are in place, safety and security work should be strengthened. It is strictly forbidden for non-staff personnel to enter and exit the power distribution room, and the staff should hold a certificate to work.

7.18 Necessary fire extinguishers should be equipped in the power distribution room.

8. Main tools