Copper busbar, field width (+85mm), . suitable for busbar supports FST901N and FST903N. Width 5. Height 5. Rated current (A) 630 (573). Copper size L1 - 3 30 x 10mm. PU 1. Copper busbars. Pre-assembled copper busbars in the sizes . 12 x 5, 20 x 5, 30 x 5, 12 x 10, 20 x 10, 30 x 10mm in the following variants:. Horizontal design: . Field width. Extended on one side (perforated copper from 20/30mm). Extended on both sides (perforated copper from 20/30mm). Shortened field width. Vertical design in field height.