We are working in an MRI facility. The MRI manufacturer, Siemens, asks that all branch wiring within the RF shield be on isolation transformers, and be ungrounded two wire. NEC 517.13 requires that all wiring in a patient exam room (an MRI is a patient exam room) have redundant grounds, i.e. a metal sheath and an insulated ground wire.
How have people handled these requirements in the past?
How have people handled these requirements in the past?