In the past, industrial and commercial electrical distribution feeder systems have generally employed cable and conduit, cable and cable tray, cable and wireway, or electrical busway. Where cable is used with conduit, the conduit must first be installed and then cables are pulled through it to complete the installation. Cable used with cable tray or wireway again involves the installation of the cable tray or wireway first and then laying of cables in the tray or wireway to complete the installation. Busway installations are generally simpler than cable and conduit or cable and tray or wireway since the conductors are already inside the protective enclosure and require no additional labor after the enclosure is installed. Busway designs of the past have generally included a number of bus bars having a rectangularly-shaped cross-section placed parallel to one another in a common plane and installed in a rectangularly shaped enclosure. The sections of busway are produced in specific lengths which can not be altered in the field during installation. For this reason, if special lengths are required they must be engineered and manufactured at the factory. This special engineering and manufacturing requires additional time for shipment to the job site and generally an increase in cost to the customer.
USPTO Backgrounds
USPTO Backgrounds