4/0 cable into the back of a 3 1/2 inch deep panel

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iwire

iwire

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Re: 4/0 cable into the back of a 3 1/2 inch deep panel

Originally posted by jibber:
The reason that 8' fluorescent light bulbs need not be covered is because there hasn't been many cases of someone being hurt by them breaking.
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Actually there are times when florescent lamps must be covered, not by the NEC but by Health codes. :D
 
J

jibber

Member
Re: 4/0 cable into the back of a 3 1/2 inch deep panel

Bob, I was only referring to the NEC on the 8' tubes. I was just trying to make a point. Does my reasoning seem out of line concerning the subject?
 
iwire

iwire

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Re: 4/0 cable into the back of a 3 1/2 inch deep panel

Originally posted by jibber:
Does my reasoning seem out of line concerning the subject?
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Heck no, I do not think your out of line, say what's on your mind. :)

Originally posted by jibber:
I was just trying to make a point.
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Yeah and I was just having some fun. :)

Here is what I think and that certainly does not mean it is correct. :)

As the name of this forum is "National Electric Code Internet Connection" I try to stay with what the code says.

Right now I believe the code says 4/0 in the back of a 3.5" panel is a violation.

If that is a needed rule or a perhaps a useless one IMO is not the point here, the rules are the rules.

Some people that come here are just starting in the trade, IMO we do them a disservice if we give the impression that we can pick and choose which rules to follow.

In answer to you question, I think you can make this bend without damage, with that I will never say to go ahead and do so.

The code making panels are made of intelligent people that have access to info I do not, I accept that they know whats best.

Certainly there are rules I do not understand the reasons behind but I will still follow them. :D
 
J

jibber

Member
Re: 4/0 cable into the back of a 3 1/2 inch deep panel

Bob, OK! But I am still having a problem believing that hundred of inspectors are overlooking a "clear" violation, or that they are not aware of the problem after 35 years. :mad:
 
ryan_618

ryan_618

Senior Member
Location
Salt Lake City, Utah
Re: 4/0 cable into the back of a 3 1/2 inch deep panel

Originally posted by jibber:
Bob, OK! But I am still having a problem believing that hundred of inspectors are overlooking a "clear" violation, or that they are not aware of the problem after 35 years. :(
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S

stew

Senior Member
Location
federal way,washington
Re: 4/0 cable into the back of a 3 1/2 inch deep panel

Gentlemen: I contacted NFPA today after talking again with Alan Manche at Square D. Alan referred me to one of the senior people at NFPA for clarification. I was actually trying to find out what the preoceedure for asking for a written clarification is because I do no have a member number with them and you need to hasve that to talk directly with them. The gentleman I spoke with however is a senior engineer for NFPA and asked that his name not be used on the forum. When I explained the situation to him he totally aqgreed with Alan that the 312.6a table and 312.6b do not apply to the depth of the panel. 408 does not appl either as this section refers you to 3126a and 3126b also. The section on pull boxes is not applicable either becuase we are talking about a panelboard which is specifically adressede in 408. He said that the note at the bottom of 312.6a was also the distance in a straight line from the terminal to the obstruction which is the top of the can. In 3126b for side space you use a dimension perpendicular to the terminal in other words to the side of the can. The distance to the front of the enclosure is not at all mentioned and does not apply.

As far as I am concerned this should endthe debate however I know a person who is U. L person who also was an NFPA rep and a well respected instructor and a long term inspector for a largew emunicipalitiy here in the Seattle area. Some of you May know him. His name is Joe Andre. I plan to cntact him as well.


)
 
W

websparky

Senior Member
Location
Cleveland, Ohio
Re: 4/0 cable into the back of a 3 1/2 inch deep panel

Stew,

In this reference;
314.28 Pull and Junction Boxes and Conduit Bodies.(A)(2)Angle or U Pulls. Where splices or where angle or U pulls are made......
Exception: Where a raceway or cable entry is in the wall of a box or conduit body opposite a removable cover, the distance from that wall to the cover shall be permitted to comply with the distance required for one wire per terminal in Table 312.6(A).
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You say doesn't apply to panels, is this because conductors in panels are somehow dfferent than conductors in a pull box with a removable cover? I fail to see the logic here. Is this one of those cases where because the code doesn't specifically spell out every possible condition we are to assume that it doesn't apply?
If the code is the minimum, and an example is set forth in one article but is not repeated again in each and every following article but, we are reasonable professionals and can understand basic concepts, why then do we need it in writting? Can't we read the code and grasp it's intent?
Surely, there must be a purpose for these tables in 312 when it states "Minimum Wire-Bending Space at Terminals AND Minimum Width of Wiring Gutters!
 
S

stew

Senior Member
Location
federal way,washington
Re: 4/0 cable into the back of a 3 1/2 inch deep panel

I say he is correct. I think the difference between a pull box and a panel board is that the wire is secured in a terminal and not looped in the box which requires more room. He said the clearances were to provide room to work in the panelboard . Think he called them the knuckebusting tables.Any how I for one am definatley convinced but as I said I am going to go one step further just for drill and talk to Joe Andre next week.
 
roger

roger

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Fl
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Retired Electrician
Re: 4/0 cable into the back of a 3 1/2 inch deep panel

I'm not going to read all the posts and this may have been touched on, but the original poster mentioned "service entrance cable" and this being the case there is a violation of 338.24 and in fact would be a violation of all the 3xx.24 articles.

Let's not use the argument that the sheath has been removed, the 3xx.24 articles do not take this into consideration.

The bottom line is, with 312 and all the cable assembly articles considered, an inspector could easily tag the installation and be justified simply using anyone of them and backing it up with 90.4 since there is no definite wording in 312.

Now if we use conduit and single conductors the nipple or connector and bushing would reduce the 3.5" to 3"

Have I ever done this? Oh yeah. ;)

Roger

[ March 13, 2004, 01:24 PM: Message edited by: roger ]
 
S

stew

Senior Member
Location
federal way,washington
Re: 4/0 cable into the back of a 3 1/2 inch deep panel

Roger what leads you to 328.24? The radius required is approx 3.5 inches for a 4/0 which can easily be obtaioned within this type of entry bend methinks. Also the wording in the tables and footnotes is very explicit in how the dimension is to be obtained,>The is not one bit of ambiguity there.

[ March 13, 2004, 01:42 PM: Message edited by: stew ]
 
roger

roger

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Fl
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Re: 4/0 cable into the back of a 3 1/2 inch deep panel

Stew, I don't see where I mentioned 324 and in fact there is no 324.24 :confused:


Also I should have said any connector and bushing would reduce the 3.5" to 3" this would include connectors for SE cable.


Roger

[ March 13, 2004, 01:47 PM: Message edited by: roger ]
 
roger

roger

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Fl
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Retired Electrician
Re: 4/0 cable into the back of a 3 1/2 inch deep panel

Stew,
The is not one bit of ambiguity there.
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then why is this thread so long? :D

Roger
 
don_resqcapt19

don_resqcapt19

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Location
Illinois
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retired electrician
Re: 4/0 cable into the back of a 3 1/2 inch deep panel

Stew,
As far as I am concerned this should endthe debate however I know a person who is U. L person who also was an NFPA rep and a well respected instructor and a long term inspector for a largew emunicipalitiy here in the Seattle area. Some of you May know him. His name is Joe Andre. I plan to cntact him as well.
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All of the above is just opinion and no more valid than yours or mine. The only way that this debate can be offically put to rest is if the NFPA issues a formal interpretation in response to a written question.
Don
 
S

stew

Senior Member
Location
federal way,washington
Re: 4/0 cable into the back of a 3 1/2 inch deep panel

Don I understand what you say . The official I spoke with is also one of the persons who would issue a written ruling as well. That is why I put a large weight upon his "opinion". I plan to ask for a written "opinion" as well or ruling .
 
don_resqcapt19

don_resqcapt19

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Location
Illinois
Occupation
retired electrician
Re: 4/0 cable into the back of a 3 1/2 inch deep panel

Stew,
The official I spoke with is also one of the persons who would issue a written ruling as well. That is why I put a large weight upon his "opinion". I plan to ask for a written "opinion" as well or ruling.
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Staff people do not write the formal interpretations. They are written by the code making panel members. When you submitt a request for a formal interpretation, you must write the question in a manner so that it can be answered "yes or no" according to the NFPA rules. The process of getting an answer can take 6 months. The rules for processing a formal interpretation appear in Section 6 of the Regulations Governing Committee Projects.
Don

[ March 13, 2004, 03:47 PM: Message edited by: don_resqcapt19 ]
 
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