Grounding System: The low-voltage side neutral point, transformer enclosure, core clamps, and other components must be reliably connected to the common grounding grid using copper conductors that meet cross-sectional area requirements; series grounding connections are strictly prohibited.
• Acceptance Testing: Upon completion of installation and prior to energization, acceptance tests-including insulation resistance, DC resistance, voltage ratio, and AC withstand voltage tests-must be performed.
• Impulse Energization: During initial energization, five no-load, full-voltage impulse energization tests must be conducted (with an interval of approximately 5 minutes between each) to verify that magnetizing inrush current does not trigger false operation of protection devices; the transformer may only be officially put into service after operating without abnormalities under no-load conditions for 24 hours.
