# No nipple through back of MB?



## Abcanfield (Jan 15, 2011)

I was told by inspector code violation - 312.6(a) - "Nothing larger than #2 through back of meter base. " I responded with exception 2.


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## Abcanfield (Jan 15, 2011)

Does exception 2 of 312.6 give compliance to installing 3/0 through back of meter base to main panel through the wall? Been doing this for years & seen it done longer than that!


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## 480sparky (Sep 20, 2007)

Insufficient information.

Ex. 2 starts to get into actual measurements, which you have not provided.


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## electures (Oct 23, 2008)

Abcanfield said:


> I was told by inspector code violation - 312.6(a) - "Nothing larger than #2 through back of meter base. " I responded with exception 2.


I agree with the inspector.


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## Abcanfield (Jan 15, 2011)

Wow. What a bully!


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## Abcanfield (Jan 15, 2011)

electures said:


> I agree with the inspector.


 you are the inspector! & I feel that you are not correct.


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## electures (Oct 23, 2008)

Abcanfield said:


> you are the inspector! & I feel that you are not correct.


Why? State the NEC section.

Just having a little fun.

Here is a link to the thread.

http://www.diychatroom.com/f18/meter-socket-panel-install-208474/index2/


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## electures (Oct 23, 2008)

This is the code violation the OP is referring to.


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## sbrn33 (Mar 15, 2007)

Is this why they make cable benders?


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## wildleg (Apr 12, 2009)

I don't have a problem with it. But you don't need my approval for the installation.

What you need, it your inspector's approval, and the approval of your poco.

there are pocos around here where you can't do that period.

what's your poco blue book say ?

if what you say is true, what's the chief inspector say ?


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## sbrn33 (Mar 15, 2007)

No POCO around here would worry about the load side. Only a **** inspector would call anybody on that around here either. 
Has anyone here ever seen this result in an electrical hazard? I know I haven't.


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## electures (Oct 23, 2008)

It is a violation of 312.6(A).


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## Nom Deplume (Jul 21, 2013)

Abcanfield said:


> I was told by inspector code violation - 312.6(a) - "Nothing larger than #2 through back of meter base. " I responded with exception 2.


Exception 2 refers to the wall opposite of the terminals and not the back wall.


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## sbrn33 (Mar 15, 2007)

That is a pretty big socket. Looks like 4 inches to me.


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## electures (Oct 23, 2008)

sbrn33 said:


> That is a pretty big socket. Looks like 4 inches to me.


It has to do with conductor deflection (NEC 312.6 &Tables A & B plus exceptions. When the conductors enter this meter enclosurer through the nipple (back) thhen Table 312.6(A) applies. The picture is not the greatest because it appears as though there may be 4" for the ungrounded conductors but less then 4" for the grounded conductor. But if we look at it from the outher direction (the panel enclosurer) it is a violation. The distance from the back of the enclosure to the panel cover measures 3 5/8". According to Table 312.6(A) 4" of space is required in order to deflect 3/0- 4/0 conductors. 1/0 - 2/0 conductors require 3 1/2" and #1 requires 3". But, once the thickness of the locknut and bushing (about 3/4") are deducted from the 3 5/8" we are left with under 3". Since the table indicates that a #2 requires a distance of 2 1/2", that is the largest conductor that can be deflected through the back of the enclosure. Unless some manufacturer makes a locknut/bushing with a combined thickness thinner then 3/4". In which case the best scenario may be 3" which will allow a #1. But I see no way of getting the 3 1/2" or 4" needed for anything larger.


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## macmikeman (Jan 23, 2007)

Use meter/main combo's, there is plenty of bending room in them and pinheads like your inspector have to go find other ways to show off how cool and smart they are.


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## btharmy (Jan 17, 2009)

electures said:


> It has to do with conductor deflection (NEC 312.6 &Tables A & B plus exceptions. When the conductors enter this meter enclosurer through the nipple (back) thhen Table 312.6(A) applies. The picture is not the greatest because it appears as though there may be 4" for the ungrounded conductors but less then 4" for the grounded conductor. But if we look at it from the outher direction (the panel enclosurer) it is a violation. The distance from the back of the enclosure to the panel cover measures 3 5/8". According to Table 312.6(A) 4" of space is required in order to deflect 3/0- 4/0 conductors. 1/0 - 2/0 conductors require 3 1/2" and #1 requires 3". But, once the thickness of the locknut and bushing (about 3/4") are deducted from the 3 5/8" we are left with under 3". Since the table indicates that a #2 requires a distance of 2 1/2", that is the largest conductor that can be deflected through the back of the enclosure. Unless some manufacturer makes a locknut/bushing with a combined thickness thinner then 3/4". In which case the best scenario may be 3" which will allow a #1. But I see no way of getting the 3 1/2" or 4" needed for anything larger.


The fact that half of the radius is inside the conduit should account for something. It is not bent at a sharp angle after exiting the conduit. I think its amazing something is blown out of proportion. It is meant to keep conductors from being bent too sharply. Besides, the meterbase is only 3/8" too narrow but the wires begin their bend well inside the conduit. It still satisfies the intent of the code.


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## sbrn33 (Mar 15, 2007)

Once again. Why make wire benders and how do the OEM's get away with it.


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## gnuuser (Jan 13, 2013)

the only possible I see is the bend may be a bit tight on the neutral conductor even if it is ok it might cause an inspector to flag it.
of course some inspectors look for loops instead of bend radius:blink:


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## electures (Oct 23, 2008)

macmikeman said:


> Use meter/main combo's, there is plenty of bending room in them and pinheads like your inspector have to go find other ways to show off how cool and smart they are.


It's funny how when an inspector doesn't catch something he is incompetent, but when he does catch it he is a pin head. Please tell us when it is ok for him to actually do his job.


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## electures (Oct 23, 2008)

sbrn33 said:


> Once again. Why make wire benders and how do the OEM's get away with it.


Wires bent with wire benders still have to comply with the NEC.


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## electures (Oct 23, 2008)

btharmy said:


> The fact that half of the radius is inside the conduit should account for something. It is not bent at a sharp angle after exiting the conduit. I think its amazing something is blown out of proportion. It is meant to keep conductors from being bent too sharply. Besides, the meterbase is only 3/8" too narrow but the wires begin their bend well inside the conduit. It still satisfies the intent of the code.


No it doesn't. The meter enclosure is only half the problem. The conductors in the panelboard enclosure do not comply with 312.6.


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## rookie sparky (Nov 6, 2014)

It's not a violation of any nec rule whatsoever due to 90.2 (b) (5)


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## electures (Oct 23, 2008)

rookie sparky said:


> It's not a violation of any nec rule whatsoever due to 90.2 (b) (5)


Wrong. 90.2(b)(5) has to do with the location of the metering and how it is supplied. 

It reads;
 (5) Installations under the exclusive control of an electric​ utility where such installations​ a. *Consist of service drops or service laterals, and associated*​ *metering, or*
 
The wiring is governed by 312.


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## Achilles (Sep 11, 2014)

It seems to me that as long as you have the minimum distance per Table 312.6(A) then you can exit the back of a meter can per code.

Can someone provide me with the code that states length of connector thread & bushing count towards wire bending space.

Thank you in advance


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## electures (Oct 23, 2008)

Achilles said:


> It seems to me that as long as you have the minimum distance per Table 312.6(A) then you can exit the back of a meter can per code.
> 
> Can someone provide me with the code that states length of connector thread & bushing count towards wire bending space.
> 
> Thank you in advance


 Note to Table 312.6(A).

 Note: Bending space at terminals shall be measured in a straight line from the end of the lug or wire connector (in the direction that the wire leaves the terminal) to the wall, barrier, or *obstruction*.​


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## Achilles (Sep 11, 2014)

electures said:


> Note to Table 312.6(A).
> 
> Note: Bending space at terminals shall be measured in a straight line from the end of the lug or wire connector (in the direction that the wire leaves the terminal) to the wall, barrier, or *obstruction*.​


I don't disagree with that measuring a straight line from the terminal to the obstruction (being the bushing) must comply with Table 312.6(A).

You mentioned defection radius from the bushing to the front of the box shall comply with Table 312.6(A).

The Note where you bold obstruction refers to termination, not entering the back of the meter.


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## electures (Oct 23, 2008)

Achilles said:


> I don't disagree with that measuring a straight line from the terminal to the obstruction (being the bushing) must comply with Table 312.6(A).
> 
> You mentioned defection radius from the bushing to the front of the box shall comply with Table 312.6(A).
> 
> The Note where you bold obstruction refers to termination, not entering the back of the meter.


Some people feel that the meter falls under the POCO requirements. As I pointed out in earlier post, 90.(2)(B)(5) applies to the metering location and how the POCO chooses to supply the service. The installation of the service entrance conductors including conductor deflection in the meter is covered under NEC 312 and other articles.

However, NEC 312 also applies to the panelboard enclosure. When the conductors enter the enclosure through a nipple in the back NEC 312.6(A) is used. The distance for the table is not based on the measurement from the back of the enclosure, but instead from the end of the conduit (nipple in this case) including the bushing and locknut. 

NEC 312.6(B) would be used for a conduit entering the enclosure directly above the terminals and only for that.

A typical 200A 1 phase residential/commercial panel measures 3 5/8 inched from the back of the enclosure (+/-). A 200A breaker can handle up to 350 kcmil. Does that mean we can punch the knockout out for 3" conduit and run the conductors in the back? No, because according to Table 312.6(A) 5" of space is needed. Take away the thickness of the locknut/bushing (approx. 5/8") from the 3 5/8" and we are left with 3" +/-. According to the table the largest conductor permitted to be installed is a #1.


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## Achilles (Sep 11, 2014)

electures said:


> The distance for the table is not based on the measurement from the back of the enclosure, but instead from the end of the conduit (nipple in this case) including the bushing and locknut.


I agree with you, and thank you for the time.

My question is where does NEC state that Table 312.6(A) is based on the end of the conduit instead of the back of the box?


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## electures (Oct 23, 2008)

Achilles said:


> I agree with you, and thank you for the time. My question is where does NEC state that Table 312.6(A) is based on the end of the conduit instead of the back of the box?


The note to the table. The conduit is considered "an obstruction ".


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## McClary’s Electrical (Feb 21, 2009)

electures said:


> Wrong. 90.2(b)(5) has to do with the location of the metering and how it is supplied.
> 
> It reads;
> (5) Installations under the exclusive control of an electric​ utility where such installations​ a. *Consist of service drops or service laterals, and associated*​ *metering, or*
> ...


No way dude. The NEC starts at the nipple leaving the meter. The meter is under exclusive control of the utility. No possible way to mosconstrue that.


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## aftershockews (Dec 22, 2012)

Bottom line is, what does the AHJ say on the matter? NEC is a guide line that we can debate till we die. What does the AHJ say?


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## McClary’s Electrical (Feb 21, 2009)

aftershockews said:


> Bottom line is, what does the AHJ say on the matter? NEC is a guide line that we can debate till we die. What does the AHJ say?


Mine understands that 90.2 b 5 has nothing to do with them. If the utility doesnt mind what happens in the meter, it's none of their business.


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## electures (Oct 23, 2008)

mcclary's electrical said:


> No way dude. The NEC starts at the nipple leaving the meter. The meter is under exclusive control of the utility. No possible way to mosconstrue that.


 Wrong. I quoted the exact text in a previous post. Locating the meter and supplying it are under the poco control. The service drop and service entrance conductors are under the NEC. Article 312 has the term meter enclosures in the title.


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## electures (Oct 23, 2008)

mcclary's electrical said:


> Mine understands that 90.2 b 5 has nothing to do with them. If the utility doesnt mind what happens in the meter, it's none of their business.


Either way nippling into the back of the panel violates conductor deflection. No way around that.


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## McClary’s Electrical (Feb 21, 2009)

electures said:


> Either way nippling into the back of the panel violates conductor deflection. No way around that.


How many electrical inspectors have you seen carry meter tags issued by the power company? 



Yeah. ....0.......


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## electures (Oct 23, 2008)

mcclary's electrical said:


> How many electrical inspectors have you seen carry meter tags issued by the power company? Yeah. ....0.......


Show me in the NEC where I am wrong. I stated the code section word for word. No getting around it. And again even if you were right, you can't nipple into the back of the panel board enclosure without complying with 312.6(A)


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## Achilles (Sep 11, 2014)

electures said:


> The note to the table. The conduit is considered "an obstruction ".


I appreciate the time electures has taken to explain the situation. Sad it seems the conversation has broken down to arguing to argue.

back on task

Table 312.6(A) Note: Bending space at terminals shall be measured in a straight line from the end of the lug or wire connector (in the direction that the wire leaves the terminal) to the wall, barrier, or obstruction.

It seems to me the Note applies only to bending radius at termination, not the deflection of conductors entering a box.

It the situation of a 200A service (3/0-4/0) 312.6(B)2 ex.2 allows termination to a lay-in term assuming you have 4" (measured in a straight line) to the obstruction (bushing)

It the meter can is 4" deep then I should have my 4" bending radius per Table 312.6(A) and if I have 4" between the terms and the bushing it seems to me the installation would be per code.

My only hang up is I don't see the wording in the code that forces me to size my box/gutter larger then required per Tables 312.6(A),(B) due to the obstruction of the bushing/nipple.


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## electures (Oct 23, 2008)

Achilles said:


> I appreciate the time electures has taken to explain the situation. Sad it seems the conversation has broken down to arguing to argue.
> 
> back on task
> 
> ...


 Read the beginning of 312.6;


*
312.6 Deflection of Conductors​* Conductors at terminals *or conductors entering or leaving*​ *cabinets or cutout boxes* and the like shall comply with​ 312.6(A) through (C).

The table is used for both, not just terminals.


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## Achilles (Sep 11, 2014)

electures said:


> Read the beginning of 312.6;
> 
> 
> *
> ...


I agree that the table applies for both, but the note below Table 312.6(A) specifically pertains to "Bending space at terminals".

I'm trying to verify where in the code the that it states that the connector/nipple/bushing impede bending radius need for box size.


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## Semi-Ret Electrician (Nov 10, 2011)

Looks/sounds like the OP and the inspector had personal problems.


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## rookie sparky (Nov 6, 2014)

90.2 b 5 means no matter how many articles you dig up and quote pertaining to terminal bending space and the like, THEY DO NOT APPLY TO A METER BASE.


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## electures (Oct 23, 2008)

rookie sparky said:


> 90.2 b 5 means no matter how many articles you dig up and quote pertaining to terminal bending space and the like, *THEY DO NOT APPLY TO A METER BASE*.


 
Wrong. Again. 90.2b only applies to metering location and how it is supplied (overhead or underground). It specifically states it in the code section. :no:


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## electures (Oct 23, 2008)

Semi-Ret Electrician said:


> Looks/sounds like the OP and the inspector had personal problems.


No problem. The OP replied to a post on DIYChatroom. I also replied to the same post. He thinks I am wrong. He started this thread to gather other opinions. I responded to his post. He didn't like my response. Oh well.


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## electures (Oct 23, 2008)

Achilles said:


> I agree that the table applies for both, but the note below Table 312.6(A) specifically pertains to "Bending space at terminals".
> 
> I'm trying to verify where in the code the that it states that the connector/nipple/bushing impede bending radius need for box size.


It does not specifically state "connector/nipple/bushing" in the NEC. They are all considered "obstructions". The final decision will fall on the EI.


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## Achilles (Sep 11, 2014)

rookie sparky said:


> 90.2 b 5 means no matter how many articles you dig up and quote pertaining to terminal bending space and the like, THEY DO NOT APPLY TO A METER BASE.


90.2(B)(5) would apply to the wire the utility company provides the customer. The service feed on the customer side of the meter is not covered. Even if your utility company owns the meter base, the wiring still needs to meet code.

If you read a little further 90.2(C) discusses special permission for wiring/equipment not owned by utility for the purpose of connecting utility power to the *service entrance conductors*.

Meaning the service entrance conductors and everything down stream is regulated by NEC. Upstream by the utility 90.2. And customer owned/shared equipment (if necessary) by NEC, but the AHJ my grant exceptions per 90.2(C)

Long way of saying 90.2(B)(5) does not apply to this discussion.


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## electures (Oct 23, 2008)

Achilles said:


> 90.2(B)(5) would apply to the wire the utility company provides the customer. The service feed on the customer side of the meter is not covered. Even if your utility company owns the meter base, the wiring still needs to meet code.
> 
> If you read a little further 90.2(C) discusses special permission for wiring/equipment not owned by utility for the purpose of connecting utility power to the *service entrance conductors*.
> 
> ...


This could be amended at the local level as well.


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## electures (Oct 23, 2008)

*Final thoughts*

Changes to the NEC in the 2014 edition clarify deflection of conductors in panelboard enclosures. 

 408.55 Wire-Bending Space Within an Enclosure Containing a Panel board.​ (A) ​​Top and Bottom Wire-Bending Space. The enclosure for a panelboard shall have the top and bottom wire bending space sized in accordance with Table 312.6(B) for the largest conductor entering or leaving the enclosure.​
_ Exception No.1: Either the top or bottom wire-bending space shall be permitted to be sized in accordance with Table 312.6(A) for a panelboard rated ​_ 225 _amperes or less and designed to contain not over _42 _overcurrent devices._​_
For the purposes of this exception, a 2-pole or a 3-pole ​_ _circuit breaker shall be considered as two or three overcurrent devices, respectively._​_
Exception No.2: Either the top or bottom wire-bending space for any panelboard shall be permitted to be sized in accordance with Table 312.6(A) where at least one side wire-bending space is sized in accordance with Table 312.6(B) for the largest conductor to be terminated in any side wire-bending space.​ Exception No.3: The top and bottom wire-bending space shall be permitted to be in accordance with Table 312.6(A) spacing ​ if the panelboard is designed and constructed for wiring using only a single 90-degree bend for each conductor; including the grounded circuit conductor; and the wiring diagram shows and specifies the method of wiring that shall be used.​
Exception No.4: Either the top or the bottom wire bending space, but not both, shall be permitted to be sized in accordance with Table 312.6(A) where there are no conductors terminated in that space.​_ (B) ​​Side Wire-Bending Space. Side wire-bending space shall be in accordance with. Table 312.6(A) for the largest conductor to be terminated in that space.​
(C) ​​Back Wiring Space. Where a raceway or cable entry is in the wall of the enclosure 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). The distance between the center of the rear entry and the nearest termination for the entering conductors shall not be less than the distance given in Table. 312.6(B).​


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