All Things Bus Duct: The Basics of Electrical Power Distribution

Bus Duct Basics

A key part of electrical power distribution is bus duct. Also called busway, bus duct provides an alternative means of conducting electricity. Bus duct is used in commercial and industrial settings to conduct electricity to power cables or cable bus. Structurally, a bus duct is a sheet metal duct containing either aluminum or copper busbars (metallic strips or bars that conduct a substantial electrical current) in a grounded metal enclosure. Bus duct is easy to maintain and flexible, helping to accommodate changing load requirements.

According to Electrical Construction & Maintenance Magazine, an online resource for the electrical design and maintenance industry, busway was first introduced in 1932 for use in the automotive industry. Since then this product has grown and now serves many other industries.
When to Install Bus Duct

Bus duct can be installed in most applications where cable or conduit would normally be used. Many people believe bus duct only serves high-amperage applications. This is a misconception–busway can provide a high degree of efficiency for both low- and high-amperage situations. Bus duct systems are manufactured ranging from 100A to 6500A. Some low-amperage applications could be high-tech companies, like computer manufacturers. High-amperage busway systems are required by heavy assembly industries like automotive.

Busway is also versatile. Thanks to developments like elbows and offsets, bus duct offers a lot of layout flexibility, like adapting to directional changes. Tap-off units or new sections can easily help meet load changes. There are some cases, however, where cable and conduit are the appropriate option. For example, bus duct cannot be installed where it’s subject to corrosive vapors.