GKW Busway is a versatile system designed for smaller commercial premises, horizontal distribution, rising mains and feeder applications, and can bring the low cost and light weight advantages of an extruded aluminium enclosure to busbar engineering. Busway is compact in size and has an inherent low impedance, which meets the requirements of customers where high current and fault handling capacities are essential.



GKW’s Busway system has been derived from the proven design and application experience gained by GKW Engineers over many years of dealing with high current and medium voltage applications. The system provides a low cost alternative to heavy mains and distribution cabling, and benefits over cables and conventional air insulated busbar systems result from the sandwich construction.


>  Low running costs from low impedence

>  High mechanical strength for short circuit withstand

>  Single body up to 5000 amps results in compact dimensions

>  Adaptable system to suit various applications

>  High IP rating at low weight and cost

>  Design through to commissioning from one source


Low voltage drop and the subsequent low running costs are inherent in low impedance systems. The aluminium enclosure minimises the magnetic field so that the system can be installed close to sensitive electronic apparatus without causing interference. A relatively high rating against the ingress of liquids or solids enables the system to be utilised in hostile environments. The small cross-section and careful selection of fittings enable major space savings in areas along the Busway run and within switchboard cubicles.

The system is designed for use as a horizontal or vertical feeder between switchboard, generators and transformer or UPS systems. With the use of tapping boxes the system can be utilised as a vertical riser or for factory distribution. With copper conductors the ratings range from 1000 amps to 5000 amps in a single housing.


Complying with BS EN 61439-6:2012 and IEC 61439, the Busway standard range is available with aluminium or copper rectangular section conductors insulated by polyester film rated at 150oC (surpassing Class B electrical insulation requirements). The enclosure, which uses a corrosion resistant aluminium alloy extrusion and is rated to IP66 (Tapping Outlets are rated at IP42), totally encloses the phase and neutral conductors in a single body. The sandwich formation results in high short circuit withstand levels and low voltage drop characteristics.

Straight sections are usually supplied in 3.5 metre lengths providing complete terminal to terminal applications in a wide range of industrial and commercial applications (with other lengths engineered to suit the busbar layout). Where equipment is utilised outdoors a weather shield/sun canopy is incorporated into the design to eliminate the effects of strong sunlight or rainwater exposure at the joints.

Throughout the range of Busway trunking a twin earth bar is solidly bolted across each joint. This earth bar has been tested in accordance with ASTA short circuit requirements and forms an integral part of our certification. Where a ‘clean’ earth is required an internal earth bar can be supplied.


A full range of bends, plug-in Tapping Boxes, offsets, additional internal/external earth bars and expansion joints and flange ends are available, as well as flexible connections and fixing accessories, expediting installation and reducing site costs. It is possible to supply an oversized neutral where this is required to accommodate unbalanced loads, and options are available for tinned or silver plated contact surfaces.

The clamping bolts use high capacity Belleville washers which are progressively tightened to the specified torque. This procedure ensures equal load sharing on multi bolt joints, a feature that cannot be obtained with shear head bolts and provides joints with a high overload capacity.

In operation the conductor temperature rise above an ambient level of 40oC does not exceed 65oC, and the efficient radiant surface of the enclosure is designed to limit the surface temperature rise to less than 55oC over ambient.