NEC gray areas

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RICK NAPIER

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A recent thread raise my curiosity on what the members might see as gray areas in the NEC. So I am asking members to post what they feel are areas not adequately covered leaving a hole for interpetation. A gray area.
 
The NEC has lots of "grey areas" for example what is the difference between physical damage and severe physical damage?

When is electrical equipment likely to require examination, adjustment, serviceing, or maintenance while energized? What electrical equipment is likely to require this?

When is something subject to physical damage?

How far can service conductors enter a building before the must terminate in the service disconnecting means?

I could go on and on.

Chris
 
RICK NAPIER said:
A recent thread raise my curiosity on what the members might see as gray areas in the NEC. So I am asking members to post what they feel are areas not adequately covered leaving a hole for interpetation. A gray area.
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Many of the members that posted in the other thread were quite adamant that the language of the code leaves little or no room for interpretations. I believe one mentioned that the language says wht the language says. . I guess the vague language just remains gray??
 
250.54 gives me heartburn everytime I see it- Auxiliary Grounding Electrodes!

Heres a picture -
1100203707_2.jpg

and some commentary.
 
raider1 said:
The NEC has lots of "grey areas" for example what is the difference between physical damage and severe physical damage?

When is electrical equipment likely to require examination, adjustment, serviceing, or maintenance while energized? What electrical equipment is likely to require this?

When is something subject to physical damage?

How far can service conductors enter a building before the must terminate in the service disconnecting means?

I could go on and on.

Chris
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I agree with raider, "on and on!" That's why we are here, to try and make sense of those areas that seem gray. We are the crayons---here to re-color the gray :D!
 
cpal said:
Many of the members that posted in the other thread were quite adamant that the language of the code leaves little or no room for interpretations.
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There is a difference (at least to me) between 'interpreting' a code section and making a judgment call when the code says to do so.

To me an interpretation would be an inspector saying 240.4(D) limits OCP for a 12 AWG to twenty amps in all cases. Or that all buried raceways require marker ribbon.

However making a judgment call about equipment being subject to damage or how far is too far with service conductors is a decision that the NEC leaves to the AHJ.


I whole heartedly subscribe to Charlie's rule :cool:

Charlie’s Rule of Technical Reading

It doesn’t say what you think it says, nor what you remember it to have said, nor what you were told that it says, and certainly not what you want it to say, and if by chance you are its author, it doesn’t say what you intended it to say. Then what does it say? It says what it says. So if you want to know what it says, stop trying to remember what it says, and don’t ask anyone else. Go back and read it, and pay attention as though you were reading it for the first time.
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Here are some that came up at an IAEI meeting that I spoke about.

1. 210.60. Are TR receptacles required in hotel/motel guest/room suites? What if the hotel/motel guest/room suite had permanent provisions for cooking.

2. 400.7 & 422.16. Other than specific appliances, can fixed or stationary appliances be flexible cord connected? If so, is there a limitation on the size and/or rating, or type of appliance?

3. 422.31, 422.32 & 424.19. What is the difference between an appliance rated over 1/8 HP, a motor driven appliance of more than 2/8 HP, and a heater containing motors rated over 1/8 HP? Is a 1/4 HP air handler considered a motor driven appliance? Is the disconnecting means required to be within sight or only capable of being locked in the open position?

4. 410.74 & 410.120. Can a recessed incandescent luminaire 100W lamp marking be field changed to 60W? If so, is a field follow up required? What lamp watt rating should be used for a lampholder, such as a pendant or keyless luminaire?

5. 400.7 & 410.82. Can a portable luminaire be secured to a bed headboard with the coard passing through and hidden by the headboard? Does it make a difference if the headboard is secured to the bed or the wall? Can a 100W incandescent luminaire be mounted on a fixed headboard? Can a 100W incandescent luminaire wired with 18 AWG SPT-2 cord include a receptacle outlet with a marked rating to limit the load to 3.5A total?

6. 110.3(A), 408.3(G) & 312.6. Where conductors enter a switchboard, and the wire bending space appears to be insufficient, is there a code violation if the requirements of 312.6 are met? How do we determine wire bending space where the raceway size is known but the conductor size is unknown? Does parallel apply to the raceways of the conductors?

7. There are 249 instances of the term "Physical damage" in the NEC. The term is not defined in the NEC. What is the intent of the term "physical Damage"? How do we determine if electrical equipment is subject to "physical damage"?

8. 110.16. Dows the field marking requirement apply only to equipment inside the occupancy only? Does the field marking requirement apply to equipment outside the occupancy too?


The summary was this.
  • the code contains many gray areas
  • identify the gray areas
  • clarify the intent
  • use reason, logic, and common sense
  • submit code change proposals
And I haven't done this much typing all month:grin:

If all else fails see Charlies' rule.
 
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