Technical Inspection Before Electric Transformer Installation

1. Measurement of winding-to-ground insulation resistance: The transformer manufacturer checks whether the transformer is damp or has insulation defects as a whole.

2. Withstand voltage test: Check whether the main insulation of the electric transformer meets the relevant national standards or relevant regulations under the specified power frequency voltage.

3. Voltage ratio measurement and connection group label verification: verify whether the transformer can achieve the expected voltage conversion effect, and whether the connection group is consistent with the nameplate.

4. Measurement of no-load current and no-load loss: Check whether the no-load current and no-load loss meet the relevant national standards and relevant regulations.

5. Measurement of short-circuit impedance and load loss: Check whether the short-circuit impedance and load loss comply with relevant national standards or relevant regulations.

6. Winding resistance measurement: Check the welding quality of the wires, whether the tap changer, static and moving contacts are in good contact, and check the balance of the three-phase DC resistance.

7. Transformer oil test: Check the electric transformer oil quality by testing the oils pressure resistance, moisture, acid value, impurities, etc., and check the verified data with the manufacturers factory test report, and analyze the changes if there are obvious changes. s reason.

8. In addition to visual inspection, the insulation resistance of amorphous alloy iron core power transformers should also be measured. When using fuses for protection, also check the short-circuit capacity and sensitivity