- Test objective:
– This test also is considered one of the main tests and its purpose is
to test:
• Voltage transformer ratio.
• Voltage transformer polarity.
• Voltage transformer winding resistance.
• Megger test (insulation).
- Required equipment:
• FA-205B CT PT analyzer
• Multi-meter (Fluke).
- Mechanical checked and visual inspection:
• Check the tightness of the connection.
• Check ferrules.
- Voltage transformer test connection
The connection mode is as shown in Figure 11 (PT), short circuit the secondary side 'a' and 'x' and connects them to the tester voltage output terminal K2, while the other voltage output terminal of the tester K1 is connected to the transformer shell.
move the controller to Test to increase the voltage and maintain it for 60s. If the flashover phenomenon occurs in the test, then CT secondary insulation against the ground is deemed to be unqualified. If the leakage current is too high, the equipment will automatically return to zero for protection.