Much of the copper in these traditionally round wires is not used because current tends to travel on the outside portion of a wire. To get around this waste, engineers at Erico International, Solon, Ohio (erico.com), stack thin laminates of copper into 100 different sizes of Flexibar to make busbars, sleeves, and braided power shunts. The laminates freely slide inside a sleeve of PVC insulation, letting them twist and bend to simplify assembly. Because they are relatively thin, all the copper carries current, so there is no unused copper such as in traditional cables. This means a round copper cable designed to handle 150 A will have a cross-sectional area over twice that of a Flexibar carrying the same 150-A load. Less copper means lower cost in terms of materials and less volume, which could be a consideration for a crowded power distribution panel. Flexibar is UL and CSA approved and comes in moisture and flame-resistant (VW-1) and fire-retardant, self-extinguishing (UL 94 V0) versions.
