Patient care areas; low voltage circuit grounding

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jaburch

Member
Are low voltage conductors routed to patient care areas required to be in metal raceway, similar to 517.13(A)?
 

marinesgt0411

Senior Member
had the same arguement with an inspector on a dental offise I did

She said it is still voltage no matter how small.

I said engineer/designer spec'ed PVC so that is what I put in and Final electrical is not the time to be telling me it is wrong.that it passed on slab inspection it passed on rough inspection.

the only reason she passed it is because it was spec'ed on the approved set of prints

517.13(B)says anything over 100 volts must be grounded.

517.82 FPN refers you back to 517.13(A)

might also read up on NFPA-99 standard for health care facilities
 

steve66

Senior Member
Location
Illinois
Occupation
Engineer
517.13A starts with "All branch circuits..." So this doesn't apply to low voltage. And 517.13B talks about "....operating at over 100V..." so it also doesn't apply to low voltage.

It starts getting tricky in Part IV of 517. See 517.61(C)(1). It sounds like they are talking about branch circuits, but nothing says "branch circuits only".

So I think if you are in an Anesthetizing location (that's part IV), then you need a metal raceway for low voltage stuff also.

Steve
 

jaburch

Member
I found this in 2005 NFPA99 Health Care Facilities. It appears to address protection from damage rather than grounding.

4.3.2.2.5.1 Wiring for low-voltage control systems and nonemergency communications and signaling systems shall not be required to be installed in metal raceways in anesthetizing locations.
THIS PRECEEDED THE ABOVE PARAGRAPH:
4.3.2.2.5 Low-voltage wiring shall comply with either of the following:
(1) Fixed systems of 30 V (dc or ac rms) or less shall be ungrounded, provided the insulation between each ungrounded conductor and the primary circuit, which is supplied from a conventionally grounded distribution system, is the same protection as required for the primary voltage.
(2) A grounded low-voltage system shall be permitted provided that load currents are not carried in the grounding conductors.

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