What is the NETA-ATS recommended test voltage for a 15-minute withstand test on a 3-phase, 34.5kV line sectionalizer?

The NETA-ATS recommended test voltage for a 15-minute withstand test on a 3-phase, 34.5kV line sectionalizer is 103 kV DC. This value is derived from guidelines that recommend a test voltage that is typically 2.5 times the highest voltage rating of the equipment plus an additional safety margin. For a 34.5 kV line, the appropriate test voltage is determined to ensure that the insulation can withstand transient voltages and to ensure long-term reliability.

Using this methodology for a line rated at 34.5 kV, multiplying by 2.5 gives approximately 86.25 kV. Adding a safety margin leads to the standard test voltage of 103 kV. This higher voltage is necessary to verify that the insulation and components of the sectionalizer can endure stress beyond their regular operating conditions without failure.

In this context, while other voltage levels may be close, they do not meet the necessary requirement set forth in the guidelines for this specific voltage class, which is crucial for maintaining safety and operational integrity in electrical systems.