range
This process standard is applicable to indoor transformer installations of 10kV and below for general industrial and civil building electrical installation projects.
Construction preparation
Equipment and material requirements:
1. The transformer should be equipped with a nameplate. The nameplate should indicate the manufacturer's name, rated capacity, primary and secondary rated voltage, current, impedance voltage % and wiring group and other technical data.
2. The capacity, specifications and models of the transformer must meet the design requirements. The accessories and spare parts are complete, and there are factory certificates and technical documents.
3. Dry-circuit transformer PD value and noise tester dB(A) value should meet the design and standard requirements.
4. Dry-type transformer with protective cover, the distance between the protective cover and the transformer shall comply with the standard, not less than the size of Table 2-23.
5. Section steel: Various specifications of steel should meet the design requirements, and there is no obvious corrosion.
6. Bolts: In addition to the anchor bolts and anti-vibration bolts, galvanized bolts shall be used with corresponding flat washers and spring washers.
7. Other materials: snake skin tube, oil resistant plastic tube, welding electrode, antirust paint, blending paint and transformer oil, all should meet the design requirements, and have product certification.
Main equipment:
1. Handling hoisting equipment: car hoist, car, hoist, hanging town, three steps, road wood, wire rope, belt rope, rolling bar.
2. Installation tools: bench drill, grinding wheel, electric welder, gas welding tool, electric hammer, bench vise, live wrench, hoe, and wire plate.
3. Test equipment: steel tape measure, steel ruler, level, line drop, shake table, multimeter, bridge and test equipment.
Operating conditions:
1. The construction drawing and technical information are complete.
2. The basic construction of the civil works is completed, and the elevation, size, structure and strength of the embedded parts are in accordance with the design requirements.
3. The transformer track is installed and meets the design requirements (Note: This work should be done by the construction and the installation unit).
4. The wall surface and roof are sprayed, the roof is free of water leakage, and the doors, windows and glass are well installed.
5. The indoor ground project is over, the site is cleaned and the road is smooth.
6. Install dry-type transformer indoors should be free of dust, and the relative humidity should be kept below 70%.
Operating process
Process flow:
Equipment point inspection→Transformer secondary handling→Transformer stabilization→Accessory installation→ Transformer core inspection and handover test→Check before power transmission→Power transmission operation acceptance
Equipment point check:
1. The inspection of equipment parts shall be carried out jointly by the installation unit, the supplier unit and the representatives of the construction unit, and make a record.
2. Check whether the specifications and models of the transformer body and accessory spare parts meet the design drawing requirements according to the equipment list, construction drawings and equipment technical documents. Whether it is complete, whether it is lost or damaged.
3. The appearance of the transformer body is inspected without damage and deformation, and the paint is intact without damage.
4. Whether the fuel tank is closed properly, whether there is oil leakage or oil leakage, whether the oil level at the oil standard is normal, and the problem should be dealt with immediately.
5. Insulating porcelain and epoxy resin castings are free from damage, defects and cracks.
Secondary handling of transformers:
1. The secondary handling of the transformer should be carried out by the lifting work industry and the electrician. It is best to use car hoisting and lifting, and it can also be hoisted by hoisting chain. It is best to use car to transport when the distance is long. It must be fixed firmly with steel wire rope during transportation. It should be smooth and minimize vibration. When the distance is short and the road is good, the hoist can be used. , rolling bar transport. Refer to Table 2-24 and Table 2-25 for the weight of the transformer and the height of the lifting point.
Resin cast dry transformer weight table 2-24
Serial number capacity (kVA) weight (t)
1 100～200 0.71～0.92
2 250～500 1.16～1.90
3 630~1000 2.08~2.73
4 1250～1600 3.39～4.22
5 2000～2500 5.14～6.30
Oil immersed power transformer weight table 2-25
Serial number capacity (kVA) Total weight (t) Hanging point height (m)
1 100～180 0.6～1.0 3.0～3.2
2 200～420 1.0～1.8 3.2～3.5
3 500～630 2.0～2.8 3.8～4.0
4 750～800 3.0～3.8 5.0
5 1000～1250 3.5～4.6 5.2
6 1600～1800 5.2～6.1 5.2～5.8
2. When the transformer is hoisted, the rigging must be inspected. The wire rope must be hung on the hook of the fuel tank. The hoist ring of the upper plate is only used for the hoisting core. The hoisting ring should not be used to lift the whole transformer (Figure 2-63).
3. When handling the transformer, care should be taken to protect the porcelain bottle. It is best to cover the high and low pressure porcelain bottle with a wooden box or a cardboard box so as not to be damaged.
4. During the handling of the transformer; there should be no impact or severe vibration. When using mechanical traction, the point of traction should be below the center of gravity of the transformer to prevent tilting. The transport angle should not exceed 15° to prevent internal structural deformation.
5. When lifting a large transformer with a dry jack, the jack should be placed in a special part of the tank.
3.3.6. Before handling or loading and unloading large transformers, the direction of the high and low pressure sides should be checked to avoid difficulties in changing the direction during installation.
Transformer stabilization:
1. The transformer can be placed in the transformer room directly by the car crane, or the temporary track can be set up with the road wood, and it can be hoisted to the temporary track by three steps and hanging chain, and then pulled into the appropriate position in the room by hoisting.
2. When the transformer is in place, it should be noted that the bearing and the wall size should be consistent with the drawing. The allowable error is ±25mm. When the drawing is not marked, the longitudinal direction is positioned according to the track. The lateral distance should not be less than 800mm, and the distance should not be less than 1000mm. Take care of the vertical line of the inner ring of the house in the center of the transformer to facilitate the suspension.
3. The track of the transformer foundation should be horizontal, the gauge and the track should be matched, and the transformer equipped with the gas relay should have its top cover with a gradient of 1% to 1.5% along the direction of the gas relay flow. Except when the slope needs to be installed).
4. When the transformer is wide-faced, the low-pressure side should be outward; when the narrow-face is propelled, the oil-pad side should generally be outward. In the case of a switch, the operating direction should be left at a width of 1200 mm or more.
5. The installation of the oil-immersed transformer should be considered to be able to check the oil level in the oil pillow and casing, the upper oil temperature, the gas relay, etc. under the condition of charging.
6. For the transformer with roller, the roller should be able to rotate flexibly. After the transformer is in place, the roller should be fixed with the brake device that can be disassembled.
7. The transformer should be installed in an earthquake-resistant manner.
Attachment installation:
Gas relay installation:
1) Gas relays should be inspected and tested before installation:
2) The gas relay should be installed horizontally. The observation window should be installed on the side for easy inspection. The direction of the arrow should be directed to the oil pillow. The connection with the communication pipe should be well sealed. The shut-off valve should be located between the oil pillow and the gas relay.
3) Open the venting nozzle and release the air until the oil overflows, and then close the venting nozzle to prevent the relay from malfunctioning.
