For a withstand test on 4.76 kV, 2500A rated switchgear, what is the appropriate maintenance test voltage according to NETA standards?

The correct choice reflects an understanding of the testing standards as recommended by NETA for high-voltage switchgear. For 4.76 kV rated switchgear, the maintenance test voltage should typically be set at a level that is effective for ensuring insulation integrity and durability of the equipment over time.

In this context, 14 kVAC and 20 kVDC are both above the rated voltage of the switchgear, providing a sufficient safety margin to validate the equipment's insulation under stress conditions without risking damage. This testing voltage helps to detect potential insulation weaknesses or failures before they can cause operational issues.

The specified values in this choice correspond well to the commonly accepted practice within the industry for withstand testing, ensuring that the equipment can handle higher voltages that may be encountered in actual operating conditions, thereby maintaining safety and reliability in electrical systems.