What is the peak test voltage for performing a VLF test on service-aged cable rated at 25kV according to NETA standards?

The peak test voltage for performing a Very Low Frequency (VLF) test on service-aged cable rated at 25kV according to NETA standards is indeed 33kV. This test voltage is selected based on a standardized ratio that ensures the cable is subjected to a sufficient level of stress to effectively assess its insulation integrity without causing damage.

In practical terms, the peak voltage used during the VLF test typically exceeds the rated voltage of the cable. NETA guidelines typically recommend using a value that approximates 1.3 times the rated voltage of the equipment being tested. For a cable rated at 25kV, this calculation leads to a test voltage of approximately 32.5kV. Rounding this value up results in the commonly accepted testing voltage of 33kV for effective evaluation of the insulation system's capabilities.

Using a voltage lower than this, such as 25kV, may not adequately stress the insulation to identify potential weaknesses. Similarly, voltages significantly higher than the recommended peak could risk damaging the cable. Likewise, testing at 20kV would not meet the requirements for proper insulation assessment, potentially leading to misjudgment regarding the cable's physical condition. Therefore, the choice of 33k