Because of the unreasonable design on insulation construction

the non-segregated buses of Third Qinshan Nuclear Power Plant suffer many faults

which cause the startup & backup transformer and the unit service transformer tripping frequently.In order to improve the reliability of the off-site power supplies and the economic benefit

the thorough technical renovation is carried out for non-segregated buses of auxiliary power system of two units.The test results and the operating condition after the renovation show that the combined non-segregated buses of porcelain insulator and cable have not only completely removed the bad effect of severe weather and high temperature difference along the line

but also met the requirement of all weather operation.