Each Track Busway housing section consists of extruded aluminum housing with an insulated strip containing copper conductors mounted on the top interior wall. The aluminum extrusion acts as a 100% ground path meeting UL 857 Standard and complies with applicable paragraphs of Section 250 of the NEC. Each housing section has an open access slot over its entire length for the insertion of snap-in plug-in units. Configurations include 2 and 4-pole varieties, rated at 40/50/60 Amp continuous duty, 480/277 Volts max. Housing sections are connected together using snap-in, in-line connectors and plate type housing couplers. Sections are supported every 10 ft max. (Support Hardware, Page 1.6) and can support 75lbs hanging weight between vertical supports. Four-pole Busway is normally used in 3-phase/4-wire power systems. Four-pole Busway may be used for 2 independent single-phase circuits at different voltages. Sections can be factory cut to any length.