I went to a service call lately to a medical office to add some isolated ground circuits for computers. I was shocked to find that the majority of the wiring, more than thirty 110V circuits, was done in 16ga MTW/THHN in EMT on 15 amp breakers. The service is 200 amp single phase and there are no problems with the installation of the service equipment or the load center. The building is less than 10 years old. It is in an area where there are no inspections or licensing required. I was taught to never use less than 12ga wire in commercial buildings and that is what I have always done but I can't find the code to back it up. I want some really solid ground to approach the owners with to convince them to do something about it. Can anyone help me with code references? Thanks!
