Tap boxes come in a few different types. The most common are explained below.
End Cable Tap Box
This the most common. The tap box plugs into one end of the busway run. A neck extends from a metal housing that encloses the lugs to supply power to the bus bars. The sides remove to allow access to the lugs. Pipe and wire are normally used to supply the power.
Plug In Tap Box
This is another common tap box solution that plugs in to plug-in busway through a port hole. These install like a bus plus (no over current protection). A plug-in tap box requires two end closures for the busway run. There are a couple of advantages to this style. One is that it can plug in anywhere along the bus run. Two, a plug-in tap box can easily be relocated along the busway line. Third, a plug-in tap box is independent of the busway material (aluminum or copper).
Center Tap Box
A center tap box allows power to be supplied to the middle of the busway run. Center tap boxes access the busway at the joints between two busway sections. This style is available for Westinghouse Lifeline busway and Siemens Bulldog busway, for example.