Large facilities can have thousands of pieces of equipment, and showing all of them at once makes any view unusable. The best approach is to let people move down through levels, from site to area to equipment, showing only the detail that makes sense at each level.
Search by tag or name should also take people straight to the equipment they want without clicking through every level, since experienced users usually know exactly what they are looking for. The site level view is then useful for the big picture, like where work is happening today, while the equipment level holds the detail.