Thank you. The exam rooms in the clinic I am working on now were wired with smurf tube (I think in '86). I found it hard to believe that met the code of the time. Just to be clear, are you saying the requirement back at least to '75 was for patient care areas to use a wiring method incorporating a conduit/sheithing that doubles as a ground?
I didn't read the whole thing but I see a reference to a common bonding point in the 75 (copper bus etc) I was wondering if that was the predecessor to the redundant ground in a metal wiring method we have now.
You're asking the wrong question. A better question would be 'when did the concept of 'patient care areas' get expanded so?'
The whole point of the original patient care area rules was to codify what had already become standard practice in areas where explosive anesthetic gasses were used; you didn't want a static charge to build up anywhere.
As an example, an 'oral surgeon' would probably need Article 517 practices in his operating area, while a dentist would not see the need.
Since then, we've lost sight of this. We've expanded 'patient care area' practically to the parking lot, while medicine has nearly completely got away from chloroform, ether, and the other explosive gasses.
I am not concerned about anesthesia locations. That doesn't apply in my situation. Perhaps the code first applied only to those locations (they have their own section today) but now the Handbook describes other scenarios as well. Essentially, any electrical equipment that a patient by him/herself or though an attendee could be contacted needs redundant grounding. Am I correct in my belief that the electrical panels feeding patient care areas, do not need such redundant grounding? In other words, can they not be fed with PVC pipe or any other non-grounding conduit?