517.3(B)(2) exception 2

[Jelloshooter848]

What seems to be the consensuses interpretation of this exception makes no sense to me. Let me lay out how I see it:

1. 517.13 says that wiring in patient care spaces needs to comply with 517.13(A) & 5173.13(B). Easy enough.

2. 517.13(A) essentially says that you raceway needs to qualify as an EGC. Easy peasy.

3. 517.3(B) says that you also need an insulated EGC to bond all the metal part. Simple.

4. OK now the exception clearly says "shall be permitted to be connected to an equipment grounding return path complying with 517.13(A) or (B)." I would like to emphasize the "or" there. That "or" did not exist prior to the 2017 nec. Before that it just said lights had to comply with just 517.13(A). I cannot imagine why they would add "or 517.13(B)" unless that means that you can choose to either have the raceway be the EGC or and insulated green conductor inside the raceway.

The common interpretation of this everywhere seems to be that this exception only exempts you from 517.13(B), but how does that make sense? If that is the intention why not just make it say something like, "shall not be required to be connected to an equipment grounding return path complying with 517.13(B)" if the intent was only to exempt the requirement of having an insulated grounding conductor?

The 2023 NEC seems to make this even more clear by moving the verbiage to the very beginning on 517.13. Right underneath where its says circuits need to comply with both A and B, there's now an exception saying lighting (7.5' AFF) require A OR B.

 

[roger]

It's basically allowing Plain Jane MC for the lighting. Before the change you would have had to use an AC type of cable or FMC meeting the requirements of 250.118

 

[david]

It's basically allowing Plain Jane MC for the lighting. Before the change you would have had to use an AC type of cable or FMC meeting the requirements of 250.118

I don't think that is what is being said
For example if schedule 40 pvc was exceptable in an an area and I used schedule 80 pvc the schedule 80 should be exceptable in place of the schedule 40

517.13 A requires a wiring method with multiple pathways to clear a fault the metal equipment ground. 517B requires in addition to A an wire type equipment ground providing a redundant equipment ground.

The exception for example is saying you can use hospital grade Mc cable where ac cable is exceptable

 

[david]

4. OK now the exception clearly says "shall be permitted to be connected to an equipment grounding return path complying with 517.13(A) or (B)." I would like to emphasize the "or" there. That "or" did not exist prior to the 2017 nec. Before that it just said lights had to comply with just 517.13(A). I cannot imagine why they would add "or 517.13(B)" unless that means that you can choose to either have the raceway be the EGC or and insulated green conductor inside the raceway.

without the (or) i guess the exception could be read you would have to use a wiring method in compliance with (A) and a wiring method in compliance with (B) would be excluded

 

[roger]

without the (or) i guess the exception could be read you would have to use a wiring method in compliance with (A) and a wiring method in compliance with (B) would be excluded

Change "could be" to "would be" and you would be correct.