The NEC requires a minimum spacing of 12 inches (305 mm) between busbars, but this can be reduced based on the busbar current and configuration. If you can place bare conductors 1/2" apart and meet the test requirements for 15kV equipment, that is fine. And before you conclude that I'm being ridiculous, remember that we do this every day in vacuum interrupters. The first is. In pollution degree 3, designers must use bigger phase-to-phase and phase-to-earth spacing, or use additional insulation barriers. These are practical values, often higher than the IEC minimums, and depend. In 1972, the Substations Committee of the IEEE published Trans. The recommendations are based on a study of actual test data of the. The metal-enclosed non-segregated phase bus runs are designed for 635 V, 5 kV, 15 kV, 27 kV and 38 kV service in accordance with ANSI C37. Available ratings are shown in Table 11. The bus will be capable of carrying rated current continuously without exceeding a conductor temperature rise of. Example: High bus at 7.
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