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Thread: 2008 NEC changes
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03-08-2009, 05:54 PM #1
2008 NEC changes
Now that I am looking back at the book that I received when I took the 2008 changes class this Saturday I am realizing that this is a year of significant changes, more than almost any other that I can remember.
*I am happy that the terms "neutral" and "neutral point" have been added.
*I am surprised that they felt compelled to change the definition of "grounding electrode".
*Table 310.15(B)(2)(c) is long overdue.
*ALL of us need to pay attention to 300.9 which affects a lot of AC installs. Anyone know of any NM that has a "W" rating?
*Many changes in 334. Less restrictive overall. There is now a way to use NM cable in Type I & II construction.
*If anyone wants to make a difference 300.4(E) has room for improvement and we will probably see more changes in this new section. A better description of "nearest surface" should probably be changed to "lowest surface" and it makes no provisions for the boxes, just the conduit. The boxes are just as likely to be penetrated as the conduit.
*334.80 will affect a ton of installations and change the way electricians wire houses.
Anyway, there were 3,688 proposals for changes and the 408 page book that I have did not list all of the actual approved changes. What I listed above barely scratches the surface. It was almost like learning the book all over again. I still cannot believe all of the 2008 changes in the NEC.
Comments welcome. This must have been difficult for those who were among the first to adopt the 2008.
Similar Threads:
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03-08-2009, 06:07 PM #2
Re: 2008 NEC changes
12-2 UF for one example.
*Many changes in 334. Less restrictive overall. There is now a way to use NM cable in Type I & II construction.
*334.80 will affect a ton of installations and change the way electricians wire houses.
What needs to be clarified there is just what "maintaining spacing" actually is. For those who have been here for a while, they will recall those discussions.
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03-08-2009, 07:20 PM #3
Re: 2008 NEC changes
The manufacturers of NM say that the conductors are THHN and we can use the 90 deg column. The problem that I see in a related area is that we sometimes see the sheat stripped from the NM cable and the conductors used which is not allowed since the NM is a listed assembly.
Yeah, UF will see more use inside liquidtight to condensing units. Not all guys carry THWN on the truck. This will be fun when 2008 is adopted.
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03-08-2009, 09:08 PM #4
Re: 2008 NEC changes
You can, but only after derating for ambient temperature first. That's the part that everyone forgets - going to 90 degree insulation was not to allow for bundling or lack of maintaining spacing, it was to allow for derating for ambient.
If you took old NM (before NMB) and tried to derate for ambient in an attic over 140 degrees (and we've all seen them), a look at the the table says nope, not allowed to use that in that attic. It was allowed for an attic up to the 132-140 degree range, but only with a 0.41 derating factor, and that was off a 20 amp rating for #14, meaning that if the old NM was in most attics, which have a temperature range of 132-140 degrees, the derated ampacity for ambient would be 20 amps x 0.41 = 8.2 amps ... and that is not including any derating for bundling or lack of maintaining spacing.
Always, always, always derate for ambient first, then bundling and lack of maintaining spacing. As you can see, there was a lot of pre-NMB installed in attics which *SHOULD NOT HAVE BEEN ALLOWED* in those attics. It is all over the country like that.
The problem that I see in a related area is that we sometimes see the sheat stripped from the NM cable and the conductors used which is not allowed since the NM is a listed assembly.
Yeah, UF will see more use inside liquidtight to condensing units. Not all guys carry THWN on the truck. This will be fun when 2008 is adopted.
Also, don't forget this: (underlining and bold are mine)
- 334.30 Securing and Supporting.
- - Nonmetallic-sheathed cable shall be supported and secured by staples, cable ties, straps, hangers, or similar fittings designed and installed so as not to damage the cable, at intervals not exceeding 1.4 m (4½ ft) and within 300 mm (12 in.) of every outlet box, junction box, cabinet, or fitting. Flat cables shall not be stapled on edge.
- - Sections of cable protectedfrom physical damage by raceway shall not be required to be secured within the raceway.
If that raceway is not for protection from physical damage, and the installation you are describing are not, then the NM cable in the raceway is not exempt from the securing requirements, plus:
- 312.5 Cabinets, Cutout Boxes, and Meter Socket Enclosures.
- - Conductors entering enclosures within the scope of this article shall be protected from abrasion and shall comply with 312.5(A) through (C).
- - - (A) Openings to Be Closed. Openings through which conductors enter shall be adequately closed.
- - - (B) Metal Cabinets, Cutout Boxes, and Meter Socket Enclosures. Where metal enclosures within the scope of this article are installed with messenger-supported wiring, open wiring on insulators, or concealed knob-and-tube wiring, conductors shall enter through insulating bushings or, in dry locations, through flexible tubing extending from the last insulating support and firmly secured to the enclosure.
- - - (C) Cables. Where cable is used, each cable shall be secured to the cabinet, cutout box, or meter socket enclosure.
- - - - Exception: Cables with entirely nonmetallic sheaths shall be permitted to enter the top of a surface-mounted enclosure through one or more nonflexible raceways not less than 450 mm (18 in.) and not more than 3.0 m (10 ft) in length, provided all of the following conditions are met:
- - - - - (a) Each cable is fastened within 300 mm (12 in.), measured along the sheath, of the outer end of the raceway.
- - - - - (b) The raceway extends directly above the enclosure and does not penetrate a structural ceiling.
- - - - - (c) A fitting is provided on each end of the raceway to protect the cable(s) from abrasion and the fittings remain accessible after installation.
- - - - - (d) The raceway is sealed or plugged at the outer end using approved means so as to prevent access to the enclosure through the raceway.
- - - - - (e) The cable sheath is continuous through the raceway and extends into the enclosure beyond the fitting not less than 6 mm (¼ in.).
- - - - - (f) The raceway is fastened at its outer end and at other points in accordance with the applicable article.
- - - - - (g) Where installed as conduit or tubing, the allowable cable fill does not exceed that permitted for complete conduit or tubing systems by Table 1 of Chapter 9 of this Code and all applicable notes thereto.
- - - - - - FPN: See Table 1 in Chapter 9, including Note 9, for allowable cable fill in circular raceways. See 310.15(B)(2)(a) for required ampacity reductions for multiple cables installed in a common raceway.
Yeppers, sure is a lot easier to just carry some THHW on their trucks.
Besides, you would not want to connect NMB to THWN which is only 75 degree C rated as you would lose some of the advantage of NMB with 90 degree C rated conductors.
The lowest rating of the conductors or terminals in the run is combined with the highest ambient and worst bundling/lack of maintaining spacing in the run when applying derating corrections factors.
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03-08-2009, 09:15 PM #5
Re: 2008 NEC changes
Correct on the derating from the 90 degree column but from what I understand, even after derating, they cannot exceed the 60 degree column anyway for NM cable. You are right, people forget that the 90 degree column is only a starting point for derating, not an ending point.
UF is terrible to strip. I saw a tool specifically made for stripping UF but I never used one. Sales of THWN in 2008 NEC states and areas must be on the rise.
Now we will see more but smaller holes drilled into the top plates in order to get "separation" and limit the cables to two per hole. Swisss cheese top plates.
BTW, the instructor shared some of the data when they tested NM cable that went through a hole with foam, fire caulk and other rated sealants and the numbers were astounding hence the clarification of this code section.
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03-08-2009, 10:03 PM #6
Re: 2008 NEC changes
I'll try to find it, there was an article on this very thing in the IAEI News, probably sometime in 2004/05. I'd been pointing that out to a high end ($10-15 mil) homes I was doing quality control inspections for and his electrician kept arguing with me that it was not necessary and that I was just blowing smoke. I, and the builder, was trying to get the electrician to do things correctly, when that article came out, I showed it to the builder who showed it to his electrician, and right then and there the rules were laid down - if I could show it in the code, and the code was the minimum, no way was the builder going to let the electrician argue or get by with anything - the builder was paying top dollar to all of his subs and he expected top dollar work, no more arguing the builder says, he is selling top dollar homes and if there is any question about code ... just remember - code is minimum and he does not want, will not have, any contractor on his jobs who thinks in "minimum" terms.
Believe it or not, but the builder went through three HVAC contractors before he found one who did not argue "meets code", he was getting top dollar and he wanted to keep getting those jobs. When the code called for flexible duct being supported a maximum every 5 feet with a 1/2" sag per foot of span between supports for a maximum sag of 2-1/2", and I wrote it up once, from that point on he had his men install the supports every 4' maximum and basically no sag. He was smiling all the way to the bank on every house.
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03-09-2009, 07:48 AM #7
Re: 2008 NEC changes
I couldn't find that older article, but here is a newer article from last year.
IAEI News Online - Restricted access.
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03-13-2009, 06:39 PM #8
Re: 2008 NEC changes
I do believe that the wire that most every electrician uses every day is dual rated THHN and THWN. So that should not be any problem.
The big issue with the damp location / wet location is to get rid of non-metallic cable, not rated for damp/wet locations, in conduits outside. The code making panel classified the inside of a conduit run outside as a wet location, thus non-metallic cable not rated for damp/wet locations, is prohibited.
Last edited by ken horak; 03-14-2009 at 05:40 AM.
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03-13-2009, 07:41 PM #9
Re: 2008 NEC changes
Ken,
Using a general term such as "romex" (which is actually "RomexTM") to represent *ALL* types of non-metallic sheathed cables and then say they are not allowed under that one given condition is incorrect in that you can get UF "romex" which is suitable for that use.
Of course most people conjure up an image of an outer sheath, paper wrapping, bare equipment ground, and two (or three) insulated conductors when one says "romex", but there are more types than just that, and in some cases it requires being more specific about what one means, such as in this case.
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03-14-2009, 05:38 AM #10
Re: 2008 NEC changes
I've correct my evil ways!
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03-14-2009, 04:05 PM #11
Re: 2008 NEC changes
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03-14-2009, 08:07 PM #12
Re: 2008 NEC changes
The one code change that I feel is going in the wrong direction is
680.26(B) (2)(b) Alternate Means Equipotential bonding CONDUCTOR ....
A single conductor is no where near as effective as a grid.
But the code now allows it if there is no rebar,steel mesh,etc.
Used to be you had to make a grid or buy one, now they say a single #8 is OK.
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03-14-2009, 08:33 PM #13
Re: 2008 NEC changes
Actually, that is only one of those "clarifications" of the code over the previous edition.
The 2005 NEC required, when no reinforcing steel was available, that bonding around the perimeter of the pool be: (underlining is mine)
- Where reinforcing steel of the pool shell or the reinforcing steel of coping stones and deck is encapsulated with a nonconductive compound or another conductive material is not available, provisions shall be made for an alternative means to eliminate voltage gradients that would otherwise be provided by unencapsulated, bonded reinforcing steel.
Okay, what does "an alternative means" mean?
Huh? Right, "who knows".
The 2008 NEC simply "clarified" that section by providing alternative methods.
Remember, though, one is not allowed to fore-go bonding to the structural reinforcing steel *WHEN PRESENT*, but one now must meet specified requirements in replacing the perimeter bonding steel *WHEN NOT PRESENT*.
One excellent example of that is, and it is all over Florida, the installation of pavers around pools for the pool decks. *THERE IS NO* reinforcing steel to bond to. What to do? Most AHJ cam up with running a solid, bare, #8 AWG copper conductor around the pool at about the mid-point of that 3 foot area, or about 18" out.
Prior to 2008 (in 2005) there was no 3 foot perimeter, however, if you sit on the side of a pool with your feet in the water and lean back on your hands, you are basically covering that 3 foot area. So put the bonding conductor in the middle of that area.
That is basically what the 2008 NEC has done - stated that is an "alternative" for "(b) Alternate Means. Where structural reinforcing steel is not available or is encapsulated in a nonconductive compound, a copper conductor(s) shall be utilized where the following requirements are met:".
If the steel is there, you MUST use it, if not there, at least now there is a specified alternative.
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03-15-2009, 06:01 AM #14
Re: 2008 NEC changes
OK now SLOW DOWN,CALM DOWN and BACK UP .
The 2005 clearly called for a grid when using the alternate Means -
( 680.26 (5)(c)(3) THE GRID HAD TO BE 12 X 12 SQUARES
the 2008 Now allows for a SINGLE conductor to be used as the alternate means.
No steel rebar or steel mesh you use the alternate means.
2005 you used a premade GRID or made a GRID
2008 you use a single #8
Sounds like a CHANGE not a Clarification. Wow it is even listed in the 2008 NEC change book as a Change.
I feel the GRID is a much better and safer method.
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03-15-2009, 12:54 PM #15
Re: 2008 NEC changes
NOPE. That is *not* what it says.
That must be where you went wrong in your thinking.
This is from the 2005 NEC.
(bold and underlining are mine)
- 680.26 Equipotential Bonding.
- - (A) Performance. The equipotential bonding required by this section shall be installed to eliminate voltage gradients in the pool area as prescribed.
- - - FPN: The 8 AWG or larger solid copper bonding conductor shall not be required to be extended or attached to any remote panelboard, service equipment, or any electrode.
- - (B) Bonded Parts. The parts specified in 680.26(B)(1) through (B)(5) shall be bonded together.
- - - (1) Metallic Structural Components. All metallic parts of the pool structure, including the reinforcing metal of the pool shell, coping stones, and deck, shall be bonded. The usual steel tie wires shall be considered suitable for bonding the reinforcing steel together, and welding or special clamping shall not be required. These tie wires shall be made tight. If reinforcing steel is effectively insulated by an encapsulating nonconductive compound at the time of manufacture and installation, it shall not be required to be bonded. Where reinforcing steel of the pool shell or the reinforcing steel of coping stones and deck is encapsulated with a nonconductive compound or another conductive material is not available, provisions shall be made for an alternative means to eliminate voltage gradients that would otherwise be provided by unencapsulated, bonded reinforcing steel.
- - - (2) Underwater Lighting. All metal forming shells and mounting brackets of no-niche luminaires (fixtures) shall be bonded unless a listed low-voltage lighting system with nonmetallic forming shells not requiring bonding is used.
- - - (3) Metal Fittings. All metal fittings within or attached to the pool structure shall be bonded. Isolated parts that are not over 100 mm (4 in.) in any dimension and do not penetrate into the pool structure more than 25 mm (1 in.) shall not require bonding.
- - - (4) Electrical Equipment. Metal parts of electrical equipment associated with the pool water circulating system, including pump motors and metal parts of equipment associated with pool covers, including electric motors, shall be bonded. Accessible metal parts of listed equipment incorporating an approved system of double insulation and providing a means for grounding internal nonaccessible, non–current-carrying metal parts shall not be bonded by a direct connection to the equipotential bonding grid. The means for grounding internal nonaccessible, non–current carrying metal parts shall be an equipment grounding conductor run with the power-supply conductors in the case of motors supplied with a flexible cord, or a grounding terminal in the case of motors intended for permanent connection.
- - - - Where a double-insulated water-pump motor is installed under the provisions of this rule, a solid 8 AWG copper conductor that is of sufficient length to make a bonding connection to a replacement motor shall be extended from the bonding grid to an accessible point in the motor vicinity. Where there is no connection between the swimming pool bonding grid and the equipment grounding system for the premises, this bonding conductor shall be connected to the equipment grounding conductor of the motor circuit.
- - - (5) Metal Wiring Methods and Equipment. Metal-sheathed cables and raceways, metal piping, and all fixed metal parts that are within the following distances of the pool, except those separated from the pool by a permanent barrier, shall be bonded.
- - - - (1) Within 1.5 m (5 ft) horizontally of the inside walls of the pool
- - - - (2) Within 3.7 m (12 ft) measured vertically above the maximum water level of the pool, or any observation stands, towers, or platforms, or any diving structures
- - (C) Equipotential Bonding Grid. The parts specified in 680.26(B) shall be connected to an equipotential bonding grid with a solid copper conductor, insulated, covered, or bare, not smaller than 8 AWG or rigid metal conduit of brass or other identified corrosion-resistant metal conduit. Connection shall be made by exothermic welding or by listed pressure connectors or clamps that are labeled as being suitable for the purpose and are of stainless steel, brass, copper, or copper alloy. The equipotential common bonding grid shall extend under paved walking surfaces for 1 m (3 ft) horizontally beyond the inside walls of the pool and shall be permitted to be any of the following: (Jerry's note: You can stop right here, the rest of this (C) are not applicable to the discussion as there is no perimeter bonding reinforcing steel, thus the alternative means is to be provided.)
- - - (1) Structural Reinforcing Steel. The structural reinforcing steel of a concrete pool where the reinforcing rods are bonded together by the usual steel tie wires or the equivalent
- - - (2) Bolted or Welded Metal Pools. The wall of a bolted or welded metal pool
- - - (3) Alternate Means. This system shall be permitted to be constructed as specified in (a) through (c):
- - - - a. Materials and Connections. The grid shall be constructed of minimum 8 AWG bare solid copper conductors. Conductors shall be bonded to each other at all points of crossing. Connections shall be made as required by 680.26(D).
- - - - b. Grid Structure. The equipotential bonding grid shall cover the contour of the pool and the pool deck extending 1 m (3 ft) horizontally from the inside walls of the pool. The equipotential bonding grid shall be arranged in a 300 mm (12 in.) by 300 mm (12 in.) network of conductors in a uniformly spaced perpendicular grid pattern with tolerance of 100 mm (4 in.).
- - - - c. Securing. The below-grade grid shall be secured within or under the pool and deck media.
- - (D) Connections. Where structural reinforcing steel or the walls of bolted or welded metal pool structures are used as an equipotential bonding grid for nonelectrical parts, the connections shall be made in accordance with 250.8.
- - (E) Pool Water Heaters. For pool water heaters rated at more than 50 amperes and having specific instructions regarding bonding and grounding, only those parts designated to be bonded shall be bonded and only those parts designated to be grounded shall be grounded.
I have not yet read your response to my other post about reading what the code says and not saying it reads something you want it to say, but the above is a perfect example of what I am referring to.
You need to not apply what is not in there, and read what is in there.
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03-15-2009, 01:46 PM #16
Re: 2008 NEC changes
Jerry -
Had you read my post about the CHANGE to 680.26(B)(2)(b) - ALTERNATE MEANS.
My Post was about the CHANGE TO ALTERNATE MEANS
and nothing else.
In the 2005 code cycle you needed to use a GRID sized 12"x12" with a tolerance of 4" Look at 680.26(C)(3) alternate means in the 2005.
In the 2008 code cycle you only need to run a single #8 copper. this is 680.26(B)(2)(b) Alternate means - in the 2008
The requirement for the grid in the alternate means has gone away.
You red lettered for us to stop before we even addressed the topic of my post!
You have gone off the "deep end" here and cut and pasted, rant and raved about something that was not even the topic of my original post.
THE CHANGES TO ALTERNATE MEANS !!!
Go ahead Jerry say it, go ahead it won't hurt, just say it!
Here I'll help you out....
I Jerry was WRO_ g.
Last edited by ken horak; 03-15-2009 at 01:48 PM. Reason: spacing
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03-15-2009, 02:53 PM #17
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03-15-2009, 04:53 PM #18
Re: 2008 NEC changes
Once again Jerry has caused another subject to go astray.
Jerry,
Here's a thought for you. Instead of relying on the search feature built in to your code copy why don't you try to follow along with the words and digest them on your own? Just because the results of the search contain the words does not necessarily mean it is the correct answer.
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03-15-2009, 05:07 PM #19
Re: 2008 NEC changes
Originally Posted by Jerry Peck;76798. - - (C) Equipotential Bonding Grid. [U
Maybe I can make this easier. Choose from one of the following answers; (A).
I bet you picked (C) didn't you?
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03-15-2009, 07:15 PM #20
Re: 2008 NEC changes
AND THAT PART IS NOT APPLICABLE!
For crying out loud Jim, READ the friggin' code.
You know, the first section which the section section relates to.
Since there is no rebar an alternate means must be used.
- 680.26 Equipotential Bonding.
- - (A) Performance. The equipotential bonding required by this section shall be installed to eliminate voltage gradients in the pool area as prescribed.
- - - FPN: The 8 AWG or larger solid copper bonding conductor shall not be required to be extended or attached to any remote panelboard, service equipment, or any electrode.
- - - (B) Bonded Parts. The parts specified in 680.26(B)(1) through (B)(5) shall be bonded together.
- - - - (1) Metallic Structural Components. All metallic parts of the pool structure, including the reinforcing metal of the pool shell, coping stones, and deck, shall be bonded. The usual steel tie wires shall be considered suitable for bonding the reinforcing steel together, and welding or special clamping shall not be required. These tie wires shall be made tight. If reinforcing steel is effectively insulated by an encapsulating nonconductive compound at the time of manufacture and installation, it shall not be required to be bonded. Where reinforcing steel of the pool shell or the reinforcing steel of coping stones and deck is encapsulated with a nonconductive compound or another conductive material is not available, provisions shall be made for an alternative means to eliminate voltage gradients that would otherwise be provided by unencapsulated, bonded reinforcing steel.
- - - - (did not include (3), (4), and (5) as they are not applicable to this discussion)
- - (C) Equipotential Bonding Grid. The parts specified in 680.26(B) shall be connected to an equipotential bonding grid with a solid copper conductor, insulated, covered, or bare, not smaller than 8 AWG or rigid metal conduit of brass or other identified corrosion-resistant metal conduit. Connection shall be made by exothermic welding or by listed pressure connectors or clamps that are labeled as being suitable for the purpose and are of stainless steel, brass, copper, or copper alloy. The equipotential common bonding grid shall extend under paved walking surfaces for 1 m (3 ft) horizontally beyond the inside walls of the pool and shall be permitted to be any of the following:
- - - (1) Structural Reinforcing Steel. The structural reinforcing steel of a concrete pool where the reinforcing rods are bonded together by the usual steel tie wires or the equivalent
- - - (2) Bolted or Welded Metal Pools. The wall of a bolted or welded metal pool
- - - (3) Alternate Means. This system shall be permitted to be constructed as specified in (a) through (c):
- - - - a. Materials and Connections. The grid shall be constructed of minimum 8 AWG bare solid copper conductors. Conductors shall be bonded to each other at all points of crossing. Connections shall be made as required by 680.26(D).
- - - - b. Grid Structure. The equipotential bonding grid shall cover the contour of the pool and the pool deck extending 1 m (3 ft) horizontally from the inside walls of the pool. The equipotential bonding grid shall be arranged in a 300 mm (12 in.) by 300 mm (12 in.) network of conductors in a uniformly spaced perpendicular grid pattern with tolerance of 100 mm (4 in.).
- - - - c. Securing. The below-grade grid shall be secured within or under the pool and deck media.
Section 3(b) clearly specifies how the 12" grid is to be constructed. You ignored the correct answer that was clearly pointed out to you.
GO BACK AND READ (3)(b), I've even highlighted the important part with red text.
What does that say?
*You* said (red text is mine for highlighting)
Section 3(b) clearly specifies how the 12" grid is to be constructed. You ignored the correct answer that was clearly pointed out to you.
BECAUSE ALL IT "CLEARLY SPECIFIES" is that "one may" construct it as stated.
Then, if one decides to do it that way (you got the "shall be permitted" part, right?), THEN AND ONLY THEN, *shall* it be made as stated.
If one decides to do it differently and the AHJ says that is good, then it is good.
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03-16-2009, 03:19 PM #21
Re: 2008 NEC changes
Jerry-
RELAX Man!
Lets start over OK
I posted that the CHANGE I felt is going in the wrong direction is :
The change going from requiring a grid ,12x12 in size to using a single copper conductor instead,when using the alternate means.
Now When there is NO structural reinforcing steel available, you use the Alternate means for the perimeter equipotential bonding.
In the 2005 NEC - Section 680.26(C) (3) (b) called for a grid ,12x12 in size
In the 2008 NEC - Section 680.26(2)(b) has dropped the requirement for the grid and allows a single conductor instead.
You quote : Shall be permitted to be constructed.....
Thats is correct under the 2005 you were ALLOWED to Construct your own grid rather then provide a factory manufactured one. Hence " Shall be permitted (allowed) to be constructed.
Keep reading after that sentence! Read a,b &c it clearly states that it is required. You can't read one sentence and stop there you must read all of the section
How much more simply can it be stated?
Maybe this way:
Dick and Jane are building a pool. Dick is using fiber reinforced concrete instead of using rebar. Jane tells Dick they need Equipotential bonding.
Dick tells Jane that seeing how there's no structural steel they can use the Alternate means listed in article 680. Jane tells Dick they are under the 2008 NEC. Dick likes that because now he can just run a # 8 copper conductor instead of making a grid like Jane had to do back when they were under the 2005 NEC. Now that everything is done, Dick Jane and Spot can run and frolic by the pool without the worry voltage grdients in the pool area.
Last edited by ken horak; 03-16-2009 at 03:28 PM.
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03-16-2009, 03:27 PM #22
Re: 2008 NEC changes
Dick asks Jane: "What? You What!? There was no requirement in 2005 to make a grid like that. All that the 2005 code said was you were "permitted" to make it like that."
Then Dick adds something like this under his breath 'Jeez, woman, no wonder we never made any money on all those pools you were in charge of building.'
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03-16-2009, 06:08 PM #23
Re: 2008 NEC changes
You better go back and read 680.26 ( C ) in the 2005 NEC
First sentence of that section states all parts specified in 680.26(B) SHALL BE ( required) connected to an Equipotential Bonding GRID.
The last sentence in that part states the Equipotential common bonding GRID SHALL (required) extend under the paved walkways for 3 feet. It also give you the option ( permissive rule- Shall be permitted) of 3 different ways to accomplish this
1) Re-bar
or
2) welded or bolted metal wall of the pool ( above ground)
OR
3) use the alternate means system Shall be permitted ( permissive rule)
to be constructed as specified in a,b,&c
The First part of that section REQUIRES A GRID the wording SHALL and SHALL NOT are Required rules in the NEC.
Shall be allowed is a permissive rule.
This section says you SHALL have a grid then it give you 3 ways to do it.
the last way is a permissive way. You may opt to make your own grid using #8 copper in a grid pattern 12x12,bonding it together where ever the copper crosses itself, and it SHALL be secured within or under the pool and deck
Jane then tells Dick he better go back and read the code! That he better learn the permissive rules and the required rules and how to tell them apart!
Then Jane mumbles" some expert" no wonder spot won't go near any pool he did or inspected!
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03-16-2009, 06:40 PM #24
Re: 2008 NEC changes
Ken,
You definitely need to take some code reading lessons.
Jane tells Dick "But it requires an equipotential bonding GRID, and that means "a grid pattern", so that is what I keep telling you."
Dick sighs to himself and says "That means that 'all of the bonding elements form, when connected together, a "bonding grid", but it does not require, refer to, or infer a "grid pattern", it is meaning a "grid effect" in that all of the bonded together components are 'at the same potential' across the grid'. Like when we go into the house and each and every receptacle outlet grounding pin is connected to a 'grounding grid' and are all at the same potential, basically the same potential as neutral, it does not mean that the wiring for those have to be laid out in a "grid pattern".
Jane interrupts " ... but ... but ... it says "grid" ... "
Dick continuous with "Yes, it says "grid" as in "grid effect", it does not mean "grid" as in "grid pattern", can you imagine what and how the electrician would have to wire the house to attain a "grid pattern"? Then, for the alternate method, *IT ALLOWS* one to use a "grid pattern", that "grid pattern" is specifically "permitted", however, all the AHJ in the state, and maybe even the country, are allowing a single #8 AWG bare copper to be run around the perimeter when there is no steel reinforcing in the pool deck, whether that pool deck be fiber reinforced concrete, pavers, or sod."
Jane goes "Umph!"
Dick says "Now don't go away mad, I was just explaining to you that "grid" *DOES NOT* mean "in a grid-like pattern of wire", that "grid" just means that all are bonded together at an equal potential."
Jane says "DON'T TOUCH ME! Get away from me."
Dick say to himself "What did I do now, I just explained to her what she asked me to?"
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03-16-2009, 06:48 PM #25
Re: 2008 NEC changes
b. Grid Structure. The equipotential bonding grid shall cover the contour of the pool and the pool deck extending 1 m (3 ft) horizontally from the inside walls of the pool. The equipotential bonding grid shall be arranged in a 300 mm (12 in.) by 300 mm (12 in.) network of conductors in a uniformly spaced perpendicular grid pattern with tolerance of 100 mm (4 in.).
Seems like the code disagrees with Jerry again. When are they going to learn?
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03-16-2009, 06:58 PM #26
Re: 2008 NEC changes
You better read it the correct way
It says zero about a so called grid effect. Grid effect - now thats funny
When rebar is used isn't it laid perpendicular to itself thus createing a grid? When steel wire is used,isn't that wire in a grid pattern? When you have no structural steel you must use the alternate means which tells you how the grid is to be made. 12 x 12 with a tolerence of 4" crossing over itself to form a grid
Beside this was the point of the original post. The nec not requiring a grid anymore but allowing a single conductor.
If you would like I can contact a leading code authority who lives down there in Florida. I'm sure he can set you straight,or at least try to
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03-16-2009, 07:09 PM #27
Re: 2008 NEC changes
Jim,
Take that up with your friend Ken, it was his post I am answering and referring to:
(underlining and red are mine)
See, the 2005 NEC *DOES NOT SAY THAT*, but, I am trying to unconfuse Ken and not confuse him more, so I let that slide by. Can you imagine his confusion if he had to try to understand that the code does not even say THAT? First we have to get the alphabet down, then we can move on to spelling and grammar.
The first sentence at 680.26(B) actually states: "(B) Bonded Parts. The parts specified in 680.26(B)(1) through (B)(5) shall be bonded together.", the word "grid" is not mentioned.
Ken then said:
The last sentence in that part states the Equipotential common bonding GRID SHALL (required) extend under the paved walkways for 3 feet. It also give you the option ( permissive rule- Shall be permitted) of 3 different ways to accomplish this
Now, if you, or Ken, had referred to 680.26(C), you would have been closer, but, no seegar as that uses the term "bonding grid" as meaning "bonding it all together at the same potential", not as meaning "bonding in a grid pattern".
The only time a "grid pattern" comes in is in 680.26(C)(3)b., and, as I have pointed out MANY TIMES BEFORE, that is *OPTIONAL*, it is *PERMITTED*.
To wit: "(3) Alternate Means. This system shall be permitted to be constructed as specified in (a) through (c): "
First, seems like you need to learn to read code too.
See that part about "shall be permitted to be "?
Your b. Grid Structure is, has I have been saying *PERMITTED* but *NOT REQUIRED*.
Not quite sure how we got to people here, you and Ken, who seem to not be able to read code, advocating code as YOU SEE IT, and yet nothing you say is actually in or from the code????
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03-16-2009, 07:28 PM #28
Re: 2008 NEC changes
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03-16-2009, 07:47 PM #29
Re: 2008 NEC changes
Jim, Jim, Jim,
Again, like Ken, when you can't find something wrong you *try* to make it up.
I didn't say what you posted, that is your reversing what I said.
A "grid" can have several meanings, and in one meaning, like that specified in (C)(3)b., it means, and specifies, 'like a grid pattern', but I've already said that.
And, another meaning, as in the overall bonding "grid" the meaning is to make all components which are bonded together at one common potential, not as in a "grid like pattern".
However, I see you cannot even read that correctly, so, maybe your problem is dyslexia?
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