The Bus Bar Size Calculator automates this entire procedure. Continuous current (or) power (in kW and voltage), 2). Safety factor (adjustable 100-200%) and 4). The calculator instantly. (1) Add Top Hat Rails, catalog number 141A-AHR45, page 23, to a module when a 141C-X40 (Adapter Extension Module) is being added to typically support the contactor on a 3 component starter. See also CrossBoard Universal Adapter Installation Instructions, publication 141C-IN004 for more information. Busbars are the backbone of switchboards, distribution boards, and electrical panels. The IEC standard for busbar sizing provides detailed guidelines to help engineers select appropriate busbar. IEC 61439 is a standard developed by the International Electrotechnical Commission (IEC) that covers design verification for low-voltage electrical products and assemblies. Enter your system's parameters (e. Proper sizing is the essential for safety, efficiency and compliance with international electrical. Below is a list of busbar sizes commonly available in the USA. If this program recommends sizes that do not fit into the ranges below, change either the number of conductors or the section thickness of the busbar and recalculate the minimum cost solution. Copyright © 2026 Copper Development.