Etap v7.5.2 doesn't have a busway option which is one of my complaints. You can use the impedance function and enter X/R values or use ohms per 100' from the GE busway spec sheets. I used the cable library "user" option and built my own busway library from GE, Siemens and Square D's bus data cut sheets.
I have a beta copy of the new ver. 11 Etap that has a new busway function but the beta version is really messed up, buggy and needs allot of work. I guess nobody at OTI knows how to spell either. The menus are loaded with spelling errors some of which are comical.

Actually it's pretty bad and some functions cause the program to crash. I'm surprised OTI would even release it.