Wiring in Dental Patient Care Area?

[olc]

Existing building (actually an old house previously a store) converted to a dentist office. The existing wiring is romex.
There are two rooms which will have dental chairs.
To confirm the way I read NEC 517.13:
Do the existing receptacles and connected wiring need to be removed?
There is an existing ceiling light fixture and switch. Does this need to be rewired to comply?

Bonus Question:
They want to put the panoramic xray (where you stand and the xray moves around your mouth) in the entry/front stairs (not used as a building entrance). Would this be considered a Patient Care Area? (all the way up through the second floor hall?)

 

[augie47]

IMO, Yes to all your questions.

 

[Buck Parrish]

Yes, too. I agree with Augie. You'll need an isolated ground. It may be possible to pull a redundant (but isolated) #12 insulated green thhn solid to these locations, not sure.

 

[augie47]

Although I have never heard the explanation, every time it has been mentioned in a Code seminar, it must be a grounding conductor in a Art 250.118 metal raceway. (Two grounding conductors will not suffice)

 

[roger]

Yes, too. I agree with Augie. You'll need an isolated ground. It may be possible to pull a redundant (but isolated) #12 insulated green thhn solid to these locations, not sure.

Buck, an isolated EGC is not allowed for 517.13 applications, there must be two EGC's connected in parallel, one of the EGC's will be the metallic raceway the other will be an insulated conductor and they will be joined together

Roger

 

[jumper]

Although I have never heard the explanation, every time it has been mentioned in a Code seminar, it must be a grounding conductor in a Art 250.118 metal raceway. (Two grounding conductors will not suffice)

I found this thread helpful in explaining it.

 

[augie47]

I found this thread helpful in explaining it.

thanks

 

[olc]

1. This applies to the light fixture and switch?

2. This applies in the xray "room" (which is the house foyer) which has a couple switches and ceiling lights?

The reason this is a concern is that it is an old house and the walls and ceilings are plaster.

 

[roger]

1. This applies to the light fixture and switch?

See the exceptions to 517.13(B), the insulated conductor can be omitted but a metallic raceway recognized as an EGC will still be needed.

2. This applies in the xray "room" (which is the house foyer) which has a couple switches and ceiling lights?

The reason this is a concern is that it is an old house and the walls and ceilings are plaster.

As far as the NEC wording it is still a Patient Care Area but, it may be worth discussing this with the AHJ.

Roger

 

[kwired]

The patient care areas need to comply with art 517. Offices, waiting rooms, corridors, and other rooms where patient care doesn't occur do not need to meet art 517. The X-ray equipment is patient care equipment and procedures so what ever space it is in is a patient care area.

So no NM cable will not be supplying any of the patient care areas, and whether or not it is still acceptable for the non patient care areas would be found in art 334, or any other articles that would apply to the specific area.