|  | 8.7 | Planning Structured Cabling: Cabling and Grounding
| 8.7.5 | How fiber optic cable can prevent electrical shocks

Most network installers today recommend the use of fiber-optic cable for backbone cabling to link wiring closets that are on different floors, of the same building, as well as between separate buildings. The reason for this is simple. It is not uncommon for floors of the same building to be fed by different power transformers. Different power transformers can have different earth grounds, thus causing the problems previously described. Non-conducting optical fibers eliminate the problem of different grounds.