Busways and busbars (conductor bars) provide current to distant or moving points along the path of an electrification system. Busbars and busways provide stationary alternatives to reels, festoons, or other retracting or moving electrification supplies.

Types of Busbars and Busways

There are three types of busbars and busways:

• Indoor busways, which have extruded housings and standard joint covers.
• Outdoor busways, which incorporate fully sealed joints and housings for weatherproof requirements.
• Plug-in busways, which provide outlets along the path for plugging in devices.

Applications

One application for busways and busbars is in building power distribution networks. Busbars and busways are designed to carry power efficiently in buildings without the hassle of conventional cable. They can supply the same high voltages in an electrical system as cable without the extended space requirements.

• Indoor feeders provide a two-piece extruded housing with standard joint covers.
• Outdoor feeders provide a weatherproof sealant around all assembled components.
• Outdoor busbars and busways may have special gasketed joints and splice covers to protect connections from the weather.
• Flexible busbars require less copper to achieve comparable ampacity and save space.

Specifications

Designing trunking systems provides for quick interchange and expansion of the components of a power supply and distribution system. Busbar units can often be added or removed without shutting down the system. These sections can come in range of sizes from 2 foot lengths to 5 foot lengths.

Adding tap-off points at specific intervals ensures a new supply is always available close to the load. These busway and busbar systems often provide reduced downtime and installation time. Plug-in busway sections are available with fusible switches, circuit breakers, and specialty plugs.Conductor bars or rails are used to conduct power to mobile points on the rail. These systems are used in the electrification of heavy cranes, monorails, and machinery.

The busbar conductor material is often aluminum or copper and can come in a number of configurations. Laminate busways and busbars can be available in copper steel or stainless clad copper with additional insulation to enclose the conductors.

When selecting a system, the number of conductors, voltage, amperage, length of the system, and application should be specified.

Standards

The manufacturer may offer installation and inspection of the busway and busbar system according to the National Electrical Contractors Association (NECA).

BS 159 - Speciication for high-voltage busbars and busbar connections

NAS44 - Busbar, electrical

CSA C22.2 NO 27 - Busways

Image credits:

Mersen | Littelfuse, Inc.