Dry Type Power Transformers Installation Specification

1. Open the box for inspection before installation

Check whether the packaging is in good condition. After the dry type power transformers is unpacked, check whether the data on the nameplate of the transformer meets the design requirements, whether the factory documents are complete, whether the transformer is in good condition, whether there is any sign of external damage, whether the parts are displaced and damaged, whether the electrical support parts or connecting wires are If there is damage, finally check whether there is any damage and shortage of spare parts.

2. Transformer installation

First check the foundation of the dry type power transformers to check whether the pre-embedded steel plate is level. There should be no cavitation phenomenon under the steel plate to ensure that the foundation of the dry type power transformers has good shock resistance and sound absorption performance, otherwise the noise of the transformer after installation will increase.

Then, use the roller to move the transformer to the installation position, remove the roller, and accurately adjust the transformer to the design position, and the installation level error meets the design requirements. Finally, four short channel steels are welded on the four corners close to the transformer base, that is, on the pre-embedded steel plate, so that the position of the transformer does not move during use.

3. Transformer wiring

When wiring, the minimum distance between the electrified body and the electrified body to the ground should be ensured, especially the distance from the cable to the high-voltage coil. The high-current low-voltage busbar should be supported separately, and should not be directly crimped on the transformer terminal to cause excessive mechanical tension and moment.

When the current is greater than 1000A (such as the 2000A low-voltage busbar used in this project), there must be a soft connection between the busbar and the transformer terminal to compensate for the thermal expansion and contraction of the conductor and to isolate the vibration of the busbar and the transformer.

The electrical connection at each wiring must maintain the necessary contact pressure, and elastic elements (such as disc-shaped plastic rings or spring washers) should be used. When tightening the connecting bolts, a torque wrench should be used.

4. dry type power transformers grounding

The grounding point of the transformer is on the base of the low-voltage side, and leads out to a special grounding bolt, which is marked with a grounding mark. The grounding of the transformer must be reliably connected to the protective grounding system through this point.

When the transformer has a casing, the casing should be reliably connected to the grounding system. When the low-voltage side adopts a three-phase four-wire system, the neutral wire should be reliably connected to the grounding system.

5. Inspection before dry type power transformers operation

Check whether all fasteners are loose, whether the electrical connection is correct and reliable, whether the insulation distance between the charged body and the charged body to the ground meets the regulations, there should be no foreign matter near the transformer, and the coil surface should be cleaned.

6. Debugging before dry type power transformers operation

(1) Check the transformation ratio and connection group of the transformer, measure the DC resistance of the high and low voltage windings, and compare the results with the factory test data provided by the manufacturer.

(2) Check the insulation resistance between the coils and the coil to the ground. If the insulation resistance is significantly lower than the equipment factory measurement data, it indicates that the transformer is damp. When the insulation resistance is lower than 1000Ω/V (operating voltage), the transformer must be dried.

(3) The test voltage of the withstand voltage test should comply with the regulations. When doing the low-voltage withstand voltage test, the temperature sensor TP100 should be taken out, and the sensor should be returned to its place in time after the test is over.

4) When the transformer is equipped with a fan, the fan should be energized and operated to ensure its normal operation.

7. Trial run

After the transformer has been carefully inspected before being put into operation, it can be energized for trial operation. During the test run, special attention must be paid to check the following points. Check for abnormal sounds, noises and vibrations. Is there any abnormal smell such as burnt smell? Whether there is discoloration caused by local overheating. Whether the ventilation is good.