Mike Holt answer incorrect/incomplete?

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Energize

Senior Member
Location
Milky Way Galaxy
I recently received, via e-mail, the EC&M code question.
http://ecmweb.com/nec/code_qa/code_qa_041708/

Someone asked if backfed breakers had to be secured to the panel.

Mike answered yes, they are required, per section 408.36 (D)


What Mike did not mention was that is not a requirement for photovoltaic power source per section 690.64 (B) (5). These backfed breakers do have be identified, and they are other requirements, but the point is there is at least one instance where the clamp requirement is not required. Perhaps there are others I am not aware of, but I am surprised there was no mention of this in Mike's answer.

Mike's answer implied ALL backfed breakers required clamping. While I might think that is a good idea, I have read enough threads here that hammer on guys who "think" and read many, many times "you might think it a good idea, but that is not what the code says."

Perhaps I should make a submittal for 2011 code change to add an exception in 408.36 (D) that references 690.64 (B) (5).

Then again, maybe I am wrong. I am referencing 2005 NEC and Mike's answers are based on 2008 NEC (I think). Perhaps 2008 is different in these two sections. I do not have a 2008 code book for research.

Does it change in the '08?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Little change in 2008 but still ok

nec 2008 690.64(B)(5) said:
Suitable for Backfeed. Circuit breakers, if backfed, shall be suitable for such operation.
FPN: Circuit breakers that are marked ?Line? and ?Load? have been evaluated only in the direction marked. Circuit breakers without ?Line? and ?Load? have been evaluated in both directions.
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
From 2008
"(6) Fastening. Listed plug-in-type circuit breakers backfed from utility-interactive inverters complying with 690.60 shall be permitted to omit the additional fastener normally required by 408.36(D) for such applications."

I belive the reason these are not required is the inverter can sense a " no power situation" on the line side and will shut down the input to the breaker.
 

radiopet

Senior Member
Location
Spotsylvania, VA
408.36(D) is the general requirement of Chapters 1-4.....

90.3 Code Arrangement. This Code is divided into the
introduction and nine chapters, as shown in Figure 90.3.
Chapters 1, 2, 3, and 4 apply generally; Chapters 5, 6, and
7 apply to special occupancies, special equipment, or other
special conditions. These latter chapters supplement or
modify the general rules. Chapters 1 through 4 apply except
as amended by Chapters 5, 6, and 7 for the particular conditions.
Chapter 8 covers communications systems and is not
subject to the requirements of Chapters 1 through 7 except
where the requirements are specifically referenced in Chapter
8.
Chapter 9 consists of tables applicable as referenced.
[ROP 1-6]
Annexes are not part of the requirements of this Code
but are included for informational purposes only.

So basically Mike is correct if he is answering to the general rule or in preference to the question asked..if the question was asked about back fed a photovolt. system then he would probably have explained the allowance listed in 690.64(B)(6)
 

Energize

Senior Member
Location
Milky Way Galaxy
radiopet said:
408.36(D) is the general requirement of Chapters 1-4.....

90.3 Code Arrangement. This Code is divided into the
introduction and nine chapters, as shown in Figure 90.3.
Chapters 1, 2, 3, and 4 apply generally; Chapters 5, 6, and
7 apply to special occupancies, special equipment, or other
special conditions. These latter chapters supplement or
modify the general rules. Chapters 1 through 4 apply except
as amended by Chapters 5, 6, and 7 for the particular conditions.
Chapter 8 covers communications systems and is not
subject to the requirements of Chapters 1 through 7 except
where the requirements are specifically referenced in Chapter
8.
Chapter 9 consists of tables applicable as referenced.
[ROP 1-6]
Annexes are not part of the requirements of this Code
but are included for informational purposes only.

So basically Mike is correct if he is answering to the general rule or in preference to the question asked..if the question was asked about back fed a photovolt. system then he would probably have explained the allowance listed in 690.64(B)(6)[/quote]


Here is the direct quote of the question:
Q. I was told that a back-fed breaker needs to be bolted into the panel. Is this correct?

I can see where your response to Mike's answer has some validity, but since the question was phrased this way, perhaps Mike should have at least acknowledged at least one exception to his answer.

I am not picking on Mike. I have purchased literally thousands of dollars worth of videos and books from him over the years. I find his opinions and graphics excellent for the most part. I also enjoy the benefits of his generosity, both on this free website and with the countless other free offers he has on his home page website.

I am just saying perhaps this one answer could have been clarified a little better. I am human too, and I do not always convey things in a clear manner. Mike has the added responsibility of thousands of people critiquing his answers, something which I and others do not have to concern ourselves.
 

mdshunk

Senior Member
Location
Right here.
I seem to recall a point in time (late 90's, maybe) where you had to pay Mike for answers to code questions. EC&M is a free magazine. I'm not sure I'd complain about something I got for free, even if it was wrong. If I paid, I'd want my money back.
 

jwelectric

Senior Member
Location
North Carolina
Mr. Holt is human just like the rest of us and most to the pencils he buys have erasers.

I disagree with some of his responses just as I disagree with many others but I don?t see this as a reason to condemn them.
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
jwelectric said:
Mr. Holt is human just like the rest of us and most to the pencils he buys have erasers.

I disagree with some of his responses just as I disagree with many others but I don?t see this as a reason to condemn them.

Amen, The code is less then crystal clear and there is lots of room for interpretation. If it were crystal clear this forum would be much less interesting , you would have Q&A that would be Q, ground up or ground down ? A, ground down. thread complete. :D
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
acrwc10 said:
From 2008
"(6) Fastening. Listed plug-in-type circuit breakers backfed from utility-interactive inverters complying with 690.60 shall be permitted to omit the additional fastener normally required by 408.36(D) for such applications."

I belive the reason these are not required is the inverter can sense a " no power situation" on the line side and will shut down the input to the breaker.

I agree. As I've stated before, this is not a true backfed breaker.
 
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