I have inspected two of these installations in my jurisdiction. NEC 517.13 requires a metal raceway for conductors. For wiring in the MRI room to the lights and receptacle, Hospital grade type AC cable with an aluminum jacket or aluminum conduit will work and comply with the code. There are also cast aluminum device boxes. Ferrous / iron is prohibited because of the magnetic field. PVC is prohibited because it is a health care facility. The wiring to the MRI machine itself is usually in the floor and is a feeder NOT a branch circuit so it doe NOT have to be in a metal raceway. The filter MUST have an enclosure supplied or fabricated to be able to attach the metal raceways and cover the wire terminations. I have had the MRI "experts" try to say that Article 517 doesn't apply because the equipment is "special" . They wanted no enclosure around the patient exam room side of the filter and the wiring method they wanted was PVC. Check with your local electrical inspector, if they have one. Alan
