Dry type transformer installation and use instructions

1. Product overview

SCB series resin-insulated dry type power transformers have the advantages of safety, reliability, energy saving and easy maintenance. Considering economy, safety, and environmental applicability, this series of transformers have broad application prospects.

The product design is advanced, the process is strict, and the test is perfect. The high-voltage winding is made of 99.9% oxygen-free copper conductor, epoxy network cloth and resin to form solid insulation. Rolled silicon steel sheets, and special binding methods. Therefore, the product has high mechanical strength and electrical strength, and has very good heat dissipation performance, the product has small partial discharge, high reliability, long operating life, no moisture absorption, flame retardant, explosion-proof, no pollution, low loss, Light weight, automatic temperature control, saving installation space, saving maintenance costs, saving energy, etc., can penetrate into the load center, suitable for urban construction, high-rise buildings, commercial centers, residential quarters, entertainment and sports centers, hospitals, tourist buildings, airports, Ports, railway stations, subways, highway tunnels, civil air defense facilities, petrochemical enterprises, electro-chemical enterprises, food industry, sewage purification, offshore oil platforms, mines and other places.

Second, the use of environmental conditions and working conditions

2.1. The altitude of the installation site shall not exceed 1000m, and the ambient temperature shall not be higher than 40°C (special design can be carried out when this requirement is exceeded).

2.2. The operating environment, relative humidity is 100%, and the environment is +40°C to -25°C (with the requirements of on-load switch and temperature controller at -25°C).

2.3. This product is generally an indoor type, and the installation site should be clean with no electrical dust, no corrosive gas, and good ventilation conditions. If installed in basements or other poorly ventilated locations, forced ventilation should be considered. This product requires about 3-4m3/min of ventilation per 1KV loss (no-load loss + load loss).

2.4. When installing the product, it should generally be 800mm away from walls and other obstacles, and there should be a distance of 300mm before the adjacent transformer. The above distance can be adjusted appropriately for distribution boxes and other occasions with limited installation space.

2.5. Under normal circumstances, the transformer can be placed directly on the site of use, and can be put into operation after installation and inspection. In the case of anti-vibration and other special requirements, the foundation for installing the transformer should be embedded with bolts, and the transformer should be fixed by bolts and nuts.

3. Main specifications and technical parameters

3.1. Rated frequency: 50HZ

3.2. Cooling method: AN or according to user requirements.

3.3. Shell protection grade:

3.4. Connection group number: DYN11 or according to user requirements.

3.5. Transformer phase sequence: facing the high-voltage side of the transformer from left to right, the high-voltage side is ABC, and the low-voltage side is abc.

3.6. Winding insulation grade: F grade.

3.7. Insulation level

The power frequency withstand voltage of 10KV products is 35KV, and the impact withstand voltage is 75KV.

The power frequency withstand voltage of 20KV grade products is 55KV, and the impact withstand voltage is 125KV.

The power frequency withstand voltage of 35KV products is 70KV, and the impact withstand voltage is 170KV.

3.8. Temperature rise limit:

Insulation system temperature (℃): 155

Maximum temperature rise (K): 100.

Five, product system description

5.1. Temperature display and temperature control system

This product can be equipped with a temperature display temperature control system according to the users requirements, and its functions are:

(1) Send an overload alarm signal and automatically display the temperature.

(2) When the internal temperature of the coil exceeds the set limit of the signal thermometer, the fan can be started and stopped, the power supply can be tripped, and the transformer can be disconnected.

5.2. Cooling system

The cooling method is self-cooling (AN). When self-cooling, the output capacity is 100%. When forced air circulation cooling (AF), the long-term overload can be 25%, and the short-term overload can be 50%.

5.3. Protection and other groups

The general protection group of this product is IP00, that is, the transformer is not equipped with a casing and is used indoors; if the user needs, it can be equipped with a casing, and IP20 or IP23 (when the transformer protection level is high, the transformer should be considered for derating operation).

Note: The IP20 enclosure can prevent the entry of solid foreign objects larger than 12mm and provide a safety barrier for the live part. On the basis of IP20, the protective shell of IP23 can prevent the inflow of water droplets within 600 angle of the vertical line.

6. Product packaging and transportation

6.1. The products are divided into two types: open type (without protective cover) and protective type (with protective cover), which are usually transported by railway, waterway and road. Controllers, air-cooling devices, outdoor shields, etc. need to be packaged separately) or packaged as a whole for transportation, and the products can be lifted and unloaded by cranes, winches or other corresponding transportation machinery.

6.2. During the transportation of the product, be sure to cover the product with a rain-proof cloth to prevent the rain from drenching.

6.3. In the process of lifting and transporting products with packaging boxes, the ropes should be hung on the sleepers at the bottom four corners of the packaging boxes. After opening the packaged products, lift them with special lifting devices, which can be lifted from the ground 100mm-150mm first. Then officially lift.

6.4. During transportation, there should be no upper and lower slopes greater than 15°C on the transportation line. In order to ensure that the vehicle can bear the load evenly, the center of gravity of the product should be located on the vertical centerline of the vehicle during loading. In order to prevent displacement and overturning of the product during transportation, the direction of the long axis of the product should be consistent with the transportation direction, and the product should be firmly bound and rolled on the transport vehicle.

6.5. When loading and unloading without a crane, the safety technical requirements should be met, and the lifting capacity should be checked to see if it matches the transport weight of the product.

6.6. For products with a trolley required by the user, a trolley with rollers is installed at the bottom, which is generally unloaded during transportation to ensure the stability of product transportation. After arriving at the destination, it is reset and installed before installation. For products with a trolley, the roller shafts at both ends of the frame can be exchanged 900 directions, and the product can be moved horizontally or vertically.

6.7. After the product is delivered to the destination, the parking time in the transportation state should be shortened as much as possible (especially in the open air). Before installation, the product should be parked in a covered, dry and ventilated place as much as possible. At the same time, measures should be taken to protect the product from mechanical wounds and filth.

Seven, inspection and acceptance

7.1. After receiving the product, the user should open the box for inspection and acceptance in time, check whether the items listed in the packing list are complete, check whether the transformer is damaged during transportation, whether the product parts are damaged and displaced, and whether the fasteners are not. Looseness, whether the insulation is damaged, whether there are traces of contamination on the surface of the coil, etc.

7.2. Check whether the data on the product nameplate is consistent with the user-locked product specification, capacity, voltage level, connection group label, short-circuit impedance, etc.

7.3. Check whether the factory technical documents are complete.

7.4. After the product is unpacked and checked, if it is not put into operation immediately, it should be repackaged and placed in a safe indoor place to prevent theft from theft.

7.5. Transformer acceptance should be signed on the corresponding handover letter with the transportation department. The handover letter should reflect the problems found during the inspection.

8. Visual inspection before installation

8.1. After opening the packing box, remove the protective device (if any) to check the external condition, pay special attention to the mechanical integrity of the coil and the iron core, the compression degree of the coil and the iron core, and the firmness of the bolts outside the connection.

8.2. After the inspection, all the solid parts and the compression parts of the coil and the iron core must be firmed again in order, and no looseness is allowed.

8.3. Disassemble, reset and install on the transformer body in accordance with the provisions of the factory technical conditions and the relevant instructions of the complete set of components.

8.4. Use dry compressed air or clean rag to clean up the dust and dirt on the product.

8.5. When the storage time is long, there are water droplets or serious condensation on the surface of the transformer, it should be dried until the insulation resistance of the coil is qualified.

9. Inspection test before putting into operation

9.1. Measure the DC resistance of high and low voltage windings (whether the data is consistent with the data given in the factory test certificate).

9.2. Check the grounding of the iron core (the grounding piece is generally located at the end of the lower iron yoke or the upper iron yoke).

9.3. Test insulation resistance

Voltage level          10KV           20KV       35KV

HV coil to LV coil≥500MΩ  ≥800MΩ     ≥1000MΩ

HV coil to ground≥500MΩ  ≥800MΩ   ≥1000MΩ

LV coil to ground≥50MΩ     ≥50MΩ     ≥50MΩ

Iron core to ground≥5MΩ   ≥5MΩ      ≥5MΩ

9.4. When doing external construction frequency withstand voltage, attention should be paid to take out the temperature control probe wire from the coil to prevent the internal components of the thermostat from being broken down.

9.5. Check whether the protection system is in good condition

9.6. The installation position of the dry type transformer should be at least 800mm away from the wall and other objects that affect the heat dissipation conditions. After the transformer is in place, the grounding bolts should be connected to the general grounding circuit for reliable grounding.

10. Network operation

10.1. After the auxiliary protection device and monitoring system are grounded and qualified, the transformer should first run under no-load, and check and adjust the protection system after three shocks are closed.

10.2. After the product leaves the factory, the tap positions of the high voltage side are connected according to the rated value position. Voltage adjustment is required during operation, and the corresponding tap connection can be made according to the tap voltage indicated on the product nameplate (when there is no excitation voltage regulation), and it must be done when the power supply of the transformer is cut off.

10.3. The transformer adopts BWDK series thermostat, and the temperature measuring element is embedded in the upper end of the low-voltage coil, which can automatically detect and display the respective working temperatures of the three-phase coils. When the coil temperature reaches the design temperature, the thermometer can automatically start the fan, stop the fan, alarm, trip, and the set temperature can be adjusted by the user according to the manual of the thermostat.

11. Maintenance

After the dry type transformer has been running for a period of time, the power should be cut off and the following necessary inspections and maintenance should be carried out.

11.1. Check coils, iron cores, sealing wires, tap terminals and fasteners in various parts, and check for damage, deformation, loosening, discoloration, overheating marks and corrosion. If there is any abnormal situation, it should be identified. reasons and take necessary measures.

11.2. Remove the dust on the transformer. All parts that can be touched by hands should be wiped with a dry cloth, but no volatile cleaners should be used. For the hard-to-wipe parts inside the iron core coil, use compressed air to blow off the dust.

11.3. The transformer installed with the fan should also remove the dust and soil in the fan (be careful not to deform the blades of the fan due to damage), check the grease of the fan bearing, and supplement or replace it if necessary.

11.4. After the inspection and maintenance are completed, before the transformer is put into operation again, it should be carefully checked whether there is any metal or non-metallic foreign matter falling off, left in the coil and iron core and on the insulating parts.

12. Safety matters

12.1. The power supply of the temperature controller (and the fan) should be obtained through the switch screen, not directly connected to the transformer.

12.2. Before the transformer is put into operation, the grounding system of the transformer room must be checked.

12.3. The door of the transformer casing should be closed to ensure the safety of electricity use.

12.4. The transformer room should have measures to prevent small animals from entering, so as to avoid accidents.

12.5. The staff must wear insulating shoes when entering the transformer room, pay attention to the safe distance of the electric part, and do not touch the transformer.

12.6. If you find that the noise of the transformer suddenly increases, you should immediately pay attention to the load condition of the transformer and the voltage of the power grid, strengthen the observation of the temperature change of the transformer, and contact the relevant personnel for consultation in time.

12.7. The transformer should be checked once every 3-5 years, and some preventive tests can also be done at this time.

12.8. The installation, test, operation and maintenance of the transformer must be undertaken by qualified professionals.