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Thread: wire size
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11-22-2009, 03:16 PM #1
wire size
I know you cannot under size wire to circuit breaker but does it hurt to oversize the wire say put a no. 12 wire on a 15 amp circuit.
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11-22-2009, 03:18 PM #2
Re: wire size
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11-22-2009, 04:11 PM #3
Re: wire size
Not only is it no problem, it may also be a good thing as it will reduce voltage drop.
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11-22-2009, 04:34 PM #4
Re: wire size
As both Dan and Jerry said. I have seen larger wires on circuit breakers when there are long distances, to decrease the voltage drop. You are more likely to see this on commercial inspections than residential.
Department of Redundancy Department
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11-23-2009, 01:11 AM #5
Re: wire size
On long runs wires stay cooler.
Breakers stay cooler with less strain on them.
On a large house with lots of long runs it can also save a little electric.
That is, if you use a lot of electric.
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11-23-2009, 08:04 AM #6
Re: wire size
as stated above over sizing wire will reduce voltage drop and you may save on your electric bill especially for long runs, the only thing to keep in mind when over sizing wire is that depending on the breaker manufacture every breaker is marked with the maximum size wire permitted to terminate on breaker and most breakers may have torque requirements marked on breaker based on the size of wire.
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11-23-2009, 08:51 AM #7
Re: wire size
Another reason to not oversize wires in general use is the habit of homeowners and general contractors to do electrical work themselves. These folks are more likely to see an oversized wire and install a higher amperage breaker thinking "hey, this should be on a bigger breaker".
On a related note, say you have a 15 amp breaker with a #12 wire at the breaker. Could you connect a #14 wire downstream? The #14 would not be undersized for the breaker, but would not match the #12.
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Supreme Emperor of Hyperbole
http://www.FullCircleInspect.com/
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11-23-2009, 09:06 AM #8
Re: wire size
Check your local code exceptions and additions
New Mexico now requires 12AWG on 15 amp general purpose outlets.
...to prevent excessive voltage drop
(And wiring errors... i.e. 14 must be bigger than 12!!!)
(2) Section 210.19 Conductors – Minimum ampacity and size. See this section of the NEC and add the following to subsection (A) Branch circuits not more than 600 volts. (1) General: see this section of the NEC and add: conductors for branch circuits shall be sized to prevent excessive voltage drop. Conductors of 15 ampere 120V branch circuits supplying general-purpose receptacle outlets shall be not less than 12 AWG.
from NM CID
14.10.4.2 SCOPE: This rule applies to all contracting work performed in New Mexico on or after July 1,2008, that is subject to the jurisdiction of CID, unless performed pursuant to a permit for which an application was received by CID before that date. [14.10.4.2 NMAC - Rp, 14.10.4.2 NMAC, 7-1-08]
Charles @ PreVue Property Inspections, Santa Fe, NM
http://www.prevuepropertyinspections.com/
"How can someone with glasses so thick be so stupid?"
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11-23-2009, 06:45 PM #9
Re: wire size
Here is something from the 2008 NEC section 250.122(B)
"(B) Increased in Size. Where ungrounded conductors are
increased in size, equipment grounding conductors, where
installed, shall be increased in size proportionately according
to the circular mil area of the ungrounded conductors."
This is unchanged from the 2002 & 2005 editions.
This is a big issue when over sizing conductors, & in some cases would disallow the use of NM & UF cables.
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11-23-2009, 06:49 PM #10
Re: wire size
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11-23-2009, 06:51 PM #11
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11-23-2009, 06:55 PM #12
Re: wire size
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11-23-2009, 06:57 PM #13
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11-23-2009, 07:01 PM #14
Re: wire size
Rollie,
I forgot to add:
(bold and underlining is mine)
- 250.122 Size of Equipment Grounding Conductors.
- (A) General. Copper, aluminum, or copper-clad aluminum equipment grounding conductors of the wire type shall not be smaller than shown in Table 250.122, but in no case shall they be required to be larger than the circuit conductors supplying the equipment. Where a cable tray, a raceway, or a cable armor or sheath is used as the equipment grounding conductor, as provided in 250.118 and 250.134(A), it shall comply with 250.4(A)(5) or (B)(4).
Being as Table 250.122 ALLOWS for the #10 equipment ground with 30 amp overcurrent device, 40 amp overcurrent device, and up to a 60 amp overcurrent device, the #10 ground would STILL be suitable for use with the NM cable the equipment ground conductor came in.
As those combinations are ALLOWED.
Now, once you get above 60 amp overcurrent device, all bets are off.
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11-23-2009, 07:03 PM #15
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11-23-2009, 07:06 PM #16
Re: wire size
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11-23-2009, 07:13 PM #17
Re: wire size
I , disagree if you upsizing for VD issues you must increase the size, if you are using in a "normal" sense such as a 40A circuit w/ 8 AWG ungrounded conductors & a 10 AWG grounding is fine, but if you use those same 8 AWG on a 15A circuit because of voltage drop issues then the EGC will need to be increased.
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11-23-2009, 07:14 PM #18
Re: wire size
Rollie,
Here is the reason and the logic for that, directly from the NEC Handbook.
- "Equipment grounding conductors on the load side of the service disconnecting means and overcurrent devices ARE SIZED BASED ON THE SIZE OF THE FEEDER OR BRANCH-CIRCUIT OVERCURRENT DEVICES ahead of them."
Thus, when you up-size the ungrounded conductor you need to up-size the grounding conductor to a compatible and suitable size for the overcurrent protection rating, however, in the 30 amp to 60 amp overcurrent protection rating range, ... the size of the grounding conductor remains the same ... so the up-sizing is built in to match the size of the feeder or branch-circuit overcurrent device, which is what the grounding conductor size is sized on.
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11-24-2009, 08:13 AM #19
Re: wire size
Good design dictates that the grounding conductor provide a low impedence path for fault current. If larger wire is installed to prevent voltage drop in the circuit it is required that the grounding conductor size be increased to keep that same voltage drop from preventing a ground fault from tripping the breaker.
250.122(B) requires that if you (for example) double the size of the ungrounded conductors you must apply a proportional size increase to the grounding conductor.
Note that this has NOTHING to do with the required size of a grounding conductor based on the overcurrent protection.
If you install #10 NM-B cable on a 30 AMP circuit a #10 grounding conductor is acceptable
If you install a #6 NM-B cable on a 55 AMP circuit a #10 grounding conductor is acceptable
If you install a #6 NM-B cable on a 30 AMP circuit the #10 grounding conductor is no longer large enough.
The assumption is that if the wire size must be increased to prevent voltage drop that the grounding conductor size has to be increased to provide a low impedence fault path. This rule applies even though the up-sized wire size has been installed to take care of derating issues and not because of voltage drop issues. In the case of #6 wire, when upsizing the grounding conductor you have to use #6 as the grouding conductor as the grounding conductor size increase has to be proportional to the ungrounded conductor size increase. In this case you are up-sizing from #10 to #6, and as #10 is the size of the required grounding conductor the proportional size increase matches the ungrounded conductor size increase.
The mistake most people make here is that while the #10 will provide a low impedence fault path for maximum loads on a #6 or #8 wire, once the #6 or #8 is used to limit voltage drop (because of length) because of its' size on a smaller circuit, then the impedence(because of increased length) of the #10 becomes an issue.
Rollie has it nailed.
Last edited by Bill Kriegh; 11-24-2009 at 08:38 AM.
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11-24-2009, 09:55 AM #20
Re: wire size
On a similar note, I have seen circuits with both 12 and 14 ga. wiring. Does that pass muster?
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11-24-2009, 10:34 AM #21
Re: wire size
It does if the wire is NM-B or some other type cable where the grounded and ungrounded conductors are the same size. Given the rules in place otherwise, a circuit that starts with a #12 cable and has a #14 spliced on would need a #12 grounding conductor all the way. But 250.122(B) says the grounding conductor doesn't have to be larger than the ungrounded conductor. So, when the ungrounded conductor reduces to #14 the ungrounded conductor can too.
This configuration, if at the end of a long run, does defeat the intent of the NEC, but not the wording. It is poor practice but is often found in DIY projects where thankfully distance from the overcurrent device isn't an issue most of the time. The wording needs attention at some point.
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11-24-2009, 10:50 AM #22
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11-24-2009, 11:07 AM #23
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11-24-2009, 06:54 PM #24
Re: wire size
Bill,
Your first two are correct, your last one is incorrect as stated.
The MAXIMUM overcurrent protection for #6 NM-B is given, not a "minimum" overcurrent protection, thus you can install a 15 amp overcurrent protection breaker on #6 NM-B and still use the #10 grounding conductor in it as the ground.
One needs to use logic and understand the reason for the logic in what the code is requiring.
Let's say that I want to run a #6 NM-B to a remote panel across my attic to where my office is, and from there I will keep my 15 amp circuits with #14 NM cable (wired before NM-B came out). There is nothing in the code which requires me to install a grounding conductor which is any larger than the approved #10 in that #6 NM-B with the #10 grounding conductor ... AND I can still protect it with a 15 amp breaker and not incur any problems.
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11-24-2009, 10:16 PM #25
Re: wire size
Sorry Jerry. I disagree. 250.122(B) specifically says that if you increase the size of the ungrounded conductor the grounding conductor has to be increased proportionally.
What the code is after is an up sized grounding conductor if the ungrounded conductor is up sized. This is specifically to provide a low impedance path to ground.
If a larger ungrounded conductor is used to limit voltage drop the grounding conductor needs to be proportionally up sized as well. That's what 250.122(B) says. It does not make exceptions for how the up sized wire is actually used.
So, again, if you feed the NM-B with a 55 AMP breaker, a #10 grounding conductor is fine. If you feed it with a 30 AMP breaker you have up sized the ungrounded conductors as #10 is what you'd use for 30 AMPs normally. And, that means you have to up size the grounding conductor as well.
I agree there are circumstances where this makes absolutely no sense, but there aren't any exceptions I can find that say it's OK not to increase the size of the grounding conductor. No argument on my part that a #10 is good for a grounding conductor at 55 AMPs. Its also good at 30 AMPs - unless youre using larger ungrounded conductors.
All this has to do with larger wire used to limit voltage drop and nothing to do with the size of the required grounding conductor for a given overcurrent device as given in table 250.122, which is just the starting point if you're upsizing conductors. Without 250.122(B) there wouldn't be any adjusting necessary. With it it's required.
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11-25-2009, 06:43 PM #26
Re: wire size
Not quite correct.
The code does not say anything about REDUCING the size of the conductors. (Other than maximum allowable overcurrent protection being based based on the smaller conductor size.)
You need to step outside the box you are building high around yourself and think a minute or two.
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11-25-2009, 08:54 PM #27
Re: wire size
I'm not building any boxes. I'm quoting a very unambiguous paragraph in the NEC. You can choose to ignore it if you wish. I can't - I've got bonified inspectors that apply it to every job that has upsized conductors present.
As to how much sense it makes in some circumstances, I'll agree it doesn't make much, sometimes any. However, one thing that seems to run through the NEC is that in order to uncomplecate things a bit, rules like this apply to most circumstances. So, wire up sized to take care of voltage drop will need a grounding conductor up sized. The rule is the same when the ungrounded conductor is upsized due to derating issues. The issue here is that the NEC doesn't care if the wire was up sized because of voltage drop, derating issues, or because it's what was kicking around in the leftover wire bin and available for the job.
Try as you might, running a #6 NM-B at 55 AMPs with a #10 ground is not the same thing as running #6 NM-B at 30 AMPs with a #10 ground. 250.122(B) says so, or at least what has to happen if you do. If you can show language that says 250.122(B) doesn't apply I'm all eyes.
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11-26-2009, 08:20 AM #28
Re: wire size
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11-26-2009, 10:35 AM #29
Re: wire size
I've been watching this thread , to see if it sorts itself out.
According to the 2008 NEC article 250.122 ( B) "where ungrounded conductors are increased in size , equipment grounding conductors, where installed, shall be increased in size proportionately according to the circular mil area of the ungrounded conductors"
The key phrase in that paragragh is " increased in size proportionately according to the circular mil area of the ungrounded conductor.
This increase has nothing to do with table 250.122, but rather it has to be calculated using the circular mil area of the conductors in question. One must refer to chapter 9 table 8 to find the circular mil area of a conductor.
Example:
15 amp circuit using #14 copper. One decides to increase the size of the conductors for what ever reason to a # 6 copper.
circular mil area of #14 copper = 4110
Circular mil area of # 6 = 26240
Step 1 is calculate the ratio of the new conductors to the existing conductors.
#14 circular mils divided into #6 circular mils
26240/4110 = 6.38
Step 2 calculate the circular mils of the new equipment ground conductor.
To find the new ground size multiply the original ground size circular mils by the ratio calculated in step 1.
Original ground size #14 = 4110 circular mils.
Ratio of increase from step 1 = 6.38
4110 * 6.38 = 26221.8 ( round up to 26222 )
Step 3 Go to Chapter 9 Table 8 to find the ground size
Chapter 9 Table 8:
# 8 = 16510 circular mils -(Too small as the ground conductor must be AT LEAST 26,222 circular mils according to step 2)
# 6 = 26,240 circular mils.
You would need to use a #6 ground, when increasing from a #14 to a # 6 on a 15 amp circuit.
You MUST do the calculation when you increase the size of the circuit conductors for any reason ( and keeping the same amperage circuit)
You use Table 250.122 to determine the size of an equipment grounding conductor to start with, BUT if you increase the circuit conductor size you no longer use table 250.122 but must do the calculation.
I also did the calculation going from a #10 to a # 6:
# 10 = 10380 circular mils, #6 = 26240 circular mils
26240 / 10380 = 2.527 ( rounded up to 2.53 -This is the ratio of increase)
Original ground size #10 10380 circular mils * 2.53 = 26261
Chapter 9 Table 8
# 10 = 10380 ,#8 = 16510 #6 = 26240, # 4 =41740
We need a ground conductor of at least 26261 circular mils.
According to Chapter 9 Table 8 -Thats a # 4 BUT .........
According to 250.122 ( A) " in no case shall the grounding conductor be larger then the circuit conductors"
So our circuit conductors are # 6 so we need to use a # 6 for the ground.
The NEC handbook has a nice explanation of this following 250.122 (B)
Welcome to the world of Electrcity and the National Electrical Code.
Theres more to it the just twisting some wire together
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11-26-2009, 10:49 AM #30
Re: wire size
Let me get this straight here:
You are saying that I can run a #8 NM-B with a #10 ground to a remote panel, but I cannot install a 15 amp breaker and CONTINUE to run that same #8 NM-B to a receptacle "because I already have that wire" where I splice on #14 to the receptacle, that I have to run a #8 grounding conductor from the receptacle to the remote panel, where I can now attach that to the #10 grounding conductor of the feeder to that remote panel.
Is that what you are saying?
Is so, why?
You are getting confused about the increasing the size by adding "for any reason", when the reason is simply "because I want to" and there is NO COMPELLING reason to do so, and thus NO COMPELLING reason to say that the wire was "upsized". Instead, as I am saying, the wire was actually "downsized" and there is no requirement for that.
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11-26-2009, 11:39 AM #31
Re: wire size
Yep you got it
The code does not give an exception to this.
It says you increase the ungrounded in size, you must increase the ground accordingly. Cut and Dry - Makes not difference why you increase the conductor size.
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11-26-2009, 07:08 PM #32
Re: wire size
Yep, cut and dried, you got that part right, but ...
The code DOES NOT require upsizing the grounding conductor to the larger size for downsizing the wiring size ... which is the part you and Bill are not getting.
As you said ... the code is cut and dry on that upsizing ... and says absolutely nothing about it on downsizing ...
Which gets back to where I started at: NOT being required to upsize the grounding conductor when you downsize the wiring.
Like you said - the code is cut and dry on that.
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11-26-2009, 08:22 PM #33
Re: wire size
Exactly what are you talking about down sizing? If you put a #8 wire on a 15 AMP breaker you are up sizing - no matter how you twist things around. It's already been stated that when you down size the current carrying conductors the grounding conductor can be reduced - and that's NOT what we're beating to death here.
What is being discussed (as your presented example) is that you can run a #8 or #6 NM-B cable to a non service equipment panel (that's a sub panel to all but a few folks) and it can contain a #10 grounding conductor AS LONG AS you feed it with a breaker at the maximum rating of the cable. Once you get to the panel and install a 15 AMP breaker to feed that same size cable to an outlet then you are required to increase the grounding conductor size proportionally, and in the case of #6 or #8 that requires the ground be the same size as the ungrounded current carrying conductors. It's that da** simple. The wire size at the 15 AMP breaker is what determines the grounding conductor size to the outlet in this case.
Doesn't matter if it doesn't make sense at first, them's the rules.
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11-26-2009, 08:39 PM #34
Re: wire size
But you are required to upsize the grounding conductor when upsizing the ungrounded for voltage drop, the code is quite clear there, I would say if someone used some larger sized wire because that was on the truck not for voltage drop issues, it would just fine to use as -is we don't get to ignore a pretty clear rule just 'cause we don't like it......
Here is a refresher.
2008 NEC section 250.122(B)
"(B) Increased in Size. Where ungrounded conductors are
increased in size, equipment grounding conductors, where
installed, shall be increased in size proportionately according
to the circular mil area of the ungrounded conductors."
Bold by me.
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11-26-2009, 09:28 PM #35
Re: wire size
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11-27-2009, 06:37 AM #36
Re: wire size
Quote:
Originally Posted by Bill Kriegh
If you install #10 NM-B cable on a 30 AMP circuit a #10 grounding conductor is acceptable
If you install a #6 NM-B cable on a 55 AMP circuit a #10 grounding conductor is acceptable
If you install a #6 NM-B cable on a 30 AMP circuit the #10 grounding conductor is no longer large enough.
"Bill,
Your first two are correct, your last one is incorrect as stated."
------------------------------------------------------------------------------------------------------------------------
"Thus, when you up-size the ungrounded conductor you need to up-size the grounding conductor to a compatible and suitable size for the overcurrent protection rating, however, in the 30 amp to 60 amp overcurrent protection rating range, ... the size of the grounding conductor remains the same ... so the up-sizing is built in to match the size of the feeder or branch-circuit overcurrent device, which is what the grounding conductor size is sized on."
----------------------------------------------------------------------------------------------------------------------------
Jerry, the above incorrect statements by you is what the discussion is about.
They directly contradict 250.122(B). Nobody ever said that if you run the #6 cable to a panel that the #10 or #6 ground had to continue to an outlet if it was fed with a #15 wire. In fact the NEC specifically says the grounding conductor doesn't have to be larger than the ungrounded conductor.
Just accept the fact you learned something and move on.
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11-27-2009, 06:52 AM #37
Re: wire size
Bill,
Let's clarify what *I* said, and then you can just accept the fact that you learned something and move on.
Below is from the posts you are referencing - you will want to re-read them to understand what is being stated:
In your same post above, you also said:
In a recent post above I agreed that Rollie has it down.
(underlined red text and bold blue text is mine)
And now you don't even like it when I am agreeing with your that ...
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11-27-2009, 07:40 AM #38
Re: wire size
Jerry-
Please explain , with out going into a cut and paste rant or twisting, how is using a larger conductor for any reason downsizing?
If I were sell my house and purchase a larger house even though I do not need the extra rooms, would this also be considered downsizing ?
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11-27-2009, 09:37 AM #39
Re: wire size
All we have here is an ego that can't deal with either
(A) Not knowing it all
or
(B) being wrong
And, it's not my ego we're having trouble with.
Jerry, I agreed with Rollie when he said the grounding conductor had to be increased in size. I DID NOT agree with him when he said it MIGHT be OK to use the smaller grounding conductor because the larger ungrounded conductor was used for reasons other than voltage drop. The NEC DOES NOT give you that option. And as a guy that gets on the board and whines and cries about the deficiencies of people in the trade because they don't do things to code you ought to know better. Can't admit you're wrong - OK, I don't really care.
Cut and paste the stuffing out of yourself. Doesn't change a thing. I'm on to the next issue.
Go ahead, get in that last word while you're at it
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11-27-2009, 02:00 PM #40
Re: wire size
Ken and Bill,
Did you even bother reading what Rollie said?
And what he said it about?
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11-27-2009, 02:55 PM #41
Re: wire size
In BC Canada you are permitted to have a larger size breaker for the wire size on space heating loads(under certain circumstances), sounds wrong but our code allows it.
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11-27-2009, 03:32 PM #42
Re: wire size
Quoted from Rollies post:
But you are required to upsize the grounding conductor when upsizing the ungrounded for voltage drop, the code is quite clear there, I would say if someone used some larger sized wire because that was on the truck not for voltage drop issues, it would just fine to use as -is we don't get to ignore a pretty clear rule just 'cause we don't like it......
The part in RED may be incorrect if he isa saying what I think he is saying.
If he is saying you can use a larger conductor for the ungrounded with out up sizing the grounding conductor, just because you have it laying around as opposed to needing it due to voltage drop. Then he is incorrect.
Why is that incorrect ?
Also from Rollies post:
Here is a refresher.
2008 NEC section 250.122(B)
"(B) Increased in Size. Where ungrounded conductors are
increased in size, equipment grounding conductors, where
installed, shall be increased in size proportionately according
to the circular mil area of the ungrounded conductors."
Where in that code article does it state the rule is only required when using larger conductors due to voltage drop and not when just using larger conductors just for the hell of it??
Like I said in my first post - You increase the ungrounded -you must increase the grounding proportionately.This is done by calculating the ratio of increase in circular mils. NOT by using table 250.122
Last edited by ken horak; 11-27-2009 at 06:17 PM.
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11-27-2009, 03:58 PM #43
Re: wire size
Let's watch the language here ... I think we're confusing different code references to 'grounded' and 'grounding.'
Also note that the grounding conductor is sized according to different rules, (and different tables), which might very well result in the grounding conductor remaining the same size, though the other wires are increased a size or two.
I think we're getting into a technical area well beyond the scope, and competence, of a home inspection.
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11-27-2009, 06:37 PM #44
Re: wire size
Ken, Bill,
Jeez guys, I know you guys are smarter than needing Electricity 101, but here goes ...
(underlining and bold are mine)
From the 2008 NEC:
- 250.122 Size of Equipment Grounding Conductors.
(A) General. Copper, aluminum, or copper-clad aluminum equipment grounding conductors of the wire type shall not be smaller than shown in Table 250.122, but in no case shall they be required to be larger than the circuit conductors supplying the equipment. Where a cable tray, a raceway, or a cable armor or sheath is used as the equipment grounding conductor, as provided in 250.118 and 250.134(A), it shall comply with 250.4(A)(5) or (B)(4).
(B) Increased in Size. Where ungrounded conductors are increased in size, equipment grounding conductors, where installed, shall be increased in size proportionately according to the circular mil area of the ungrounded conductors.
Okay, let me try to explain it to you again ...
(A) above specifies how to size the equipment grounding conductors.
(B) above specifies that if THERE IS A NEED to upsize the grounded conductors, then THAT SAME NEED is applied to upsizing the grounding conductors. But do not seem to: a) believe me; b) grasp it; c) or need some greater authority to explain it to you ... so ... I am presuming that you two have the Handbook ... right? ... so, here is that "greater authority":
From the 2008 NEC Handbook:
- Equipment grounding conductors on the load side of the service disconnecting means and overcurrent devices are sized based on the size of the feeder or branch-circuit overcurrent devices ahead of them. Where the ungrounded circuit conductors are increased in size to compensate for voltage drop or for any other reason related to proper circuit operation, the equipment grounding conductor must be increased proportionately.
Understand now?
It is not just me trying to explain that to you, it is the entire NFPA organization behind the approved NFPA NEC Handbook trying to explain it to you, saying ... Hey, guys, THIS IS WHAT WE MEAN by "upsize".
Ken, Bill, I don't just make this stuff up, I have back up support for it. READ IT. THINK ABOUT IT. I am sure you will understand it and the reason for it.
It is not just me, and it is not just Rollie and me, it is the way it is, based on the authority behind the NEC.
Instead of trying to convince me that I am wrong and that I should just roll over and accept your wrong interpretation, you guys NEED TO READ THE BACK UP SUPPORTING DOCUMENTATION FIRST.
Now, though, it is your turn to do as you were telling me to do ... admit you were wrong, accept it, then move on.
Jeez.
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11-27-2009, 07:22 PM #45
Re: wire size
OK, so where does the downsizing come into play? I only see it mentioned in Jerry's posts.
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11-27-2009, 07:32 PM #46
Re: wire size
Jim,
That's what I keep pointing out ... that no "upsizing" has occurred, only "downsizing" and "downsizing" is not even addressed in the NEC ... which I am sure you also read in my posts.
One can run a #8 to a receptacle, and because the terminals are not rated for accepting a #8, one can "downsize" the conductor by connecting to a #14 with a wire nut (or other approved wire connector) so that the #14 will fit into the terminal of the receptacle.
Ken and Bill are trying to say that the #14 'has been upsized' to a #8 when in fact the the #8 'has been downsized' to a #14.
I keep pointing out that the code does not address the above (does not address "downsizing"), other than to state that the #14 is to be protected by a 15 amp rated overcurrent protective device or smaller, which means the #8 is also protected by that same 15 amp overcurrent device.
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11-27-2009, 08:26 PM #47
Re: wire size
After reading that view it still seems clear, as others have said, that the EGC would need to be upsized to correlate with the increased size of the ungrounded conductors.
The only point of ambiguity that I could see was if a larger conductor size were run and it was not for voltage drop issues, but as a matter of using what was on hand. Since this would not fit either the condition of for proper circuit operation, nor for VD, I could see how someone could take the stance that there is no need to upsize the EGC in this instance. I believe it was Ken that takes the opposing opinion.
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11-27-2009, 09:07 PM #48
Re: wire size
Jim,
You do realize that if both paragraphs are responding to what I posted that they are contradictory, don't you?
The first saying that, if that is the case, the EGC would need to be upsized, while the second saying that, it that is the case the EGC would not need to be upsized.
I believe it was Ken that takes the opposing opinion.
The NEC Handbook, myself, Rollie, and now possibly you (not sure based you your two contradictory paragraphs) have taken the position that it was not done for any "need" (such as voltage drop or some other reason to make the circuit work properly) then upsizing the EGC is not necessary.
Still waiting to hear from Ken and Bill after they have read what the Handbook said on it.
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11-27-2009, 10:35 PM #49
Re: wire size
I have to retract my statement about upsizing, there does seem to be no exception to upsizing the grounding conductor when upsizing the ungrounded, my mistake, will not be my 1st & will not be my last mistake.
Thank you, Ken.
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11-28-2009, 05:46 AM #50
Re: wire size
JP
I see you now have a handbook.
I also see you fail to acknowledge the fact that when one increases the size of the circuit conductors one must calculate the size based on circular mils NOT by table 250.122, as explained in the commentary you quoted 1/2 of.
This goes to your first argument of using a # 10 grounding conductor on a 60 amp circuit.
Which is wrong.
Then you realize you are incorrect and in true Peck fashion you just twist off the original topic and come up with some off the wall twist , that I don't think you even believe, but can not admit your incorrect.
Lets get real here your saying thqat if I run #8 conductors from 15 ampere circuit breaker then splice 14 at the receptacle , you can use a 14 grounding conductor the ENTIRE way because you " downsized"?
WRONG!
The circuit conductors are # 8 which are considered increased in size. Thus one must do the calculation to determine the "Proportionately sized" grounding conductor, which turns out to be a # 8.
When you "downsize" the conductors by splicing #14 conductors to them at the receptacle. You also use a # 14 grounding conductor. You have taken the increased circuit conductors back to the normal allowable size thus you would also take the ground back to a 14, as the grounding conductor does not need to be larger then the circuit conductors( which are now #14 ).
You size your grounding conductors according to 250.122 by using either table 250.122 ( when you have not increased the ungrounded conductors in size) or by calculating the size ( when increase in size of grounded conductors occur)
When you wish to discuss this as a professional let me know until then ........
Last edited by ken horak; 11-28-2009 at 08:00 AM.
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11-28-2009, 05:48 AM #51
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11-28-2009, 06:54 AM #52
Re: wire size
Once upon a time in these very forums, there was a lengthy discussion about tape being a permanent marking on wire. Although the code handbook specifically lists tape as an option, we have a "master" inspector type that preaches that tape isn't permanent and since the NEC doesn't specifically list tape as an option you can't use it. This in spite of the fact it is a common and accepted practice.
Now comes this same inspector type grabbing verbage from the same handbook, which by the way has no force of law anyplace I'm aware of, and is attempting to use it as a way to "prove" that a statement taken directly from the code book doesn't mean what it says. This in spite of the fact the NEC code language is a common, accepted, and enforced practice.
My opinion is simple. The code language is unambiguous. The rule has NO exceptions listed in the NEC. The code language is trade practice. The code language is law where the NEC is adopted. The handbook language partially contradicts what the code says. That makes it wrong - wouldn't be the first or will it be the last time. And, Jerry doesn't get to cherry pick what he's willing to accept or not as the rule of law from the handbook depending on whether or not he's on the loosing side of an argument.
Some of us are here to learn, others appear to be here simply to let us know they already know it all.
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11-28-2009, 08:36 AM #53
Re: wire size
Using your example I agree that the wire is upsized as the load is only 15 amps. Not considering the voltage drop issue, since a #14 conductor is sufficient for the OCPD and you have run a larger conductor I don't see how this could be considered anything but upsizing.
Jerry, if you are saying 250.122 A nd B contradict each other I will have to disagree. The conditions stated are an OR condition. You would use (A) to size your EGC unless you have upsized for VD or proper circuit operation. If upsized for VD than (B) would have to be used as the sizing criteria. Logic conditions like AND and OR are commonly used and well understood. We probably make decisions like this every day at dinner. We are having roast beef AND mashed potatoes. Would you like peas or string beans? The fact of the vegetable choice does not affect that the meal is roast beef and potatoes. They are an additional condition.
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11-28-2009, 10:36 AM #54
Re: wire size
And we now have that same other person, who swore by what the Handbook was allowing and disregarding what the code stated and who is not disregarding what the Handbook is saying and trying to now stick to the code.
*IF* you have noticed recently, *I* have stopped calling tape not suitable for permanent re-identification as the 2011 NEC will likely include that as a stated option.
On the other hand, we have Bill and Ken who flip-flop back and forth between the code, depending on which one supports their point of view.
The Handbook, in most places, are not adopted as enforceable code, in some place it is, however, in the places where the NEC is adopted and the Handbook is not - knowledgeable inspector are FIRST going to the Handbook to see what the INTENT of the NEC is.
And the INTENT of the NEC on this issue is as the Handbook states:
From the 2008 NEC Handbook:
- Equipment grounding conductors on the load side of the service disconnecting means and overcurrent devices are sized based on the size of the feeder or branch-circuit overcurrent devices ahead of them. Where the ungrounded circuit conductors are increased in size to compensate for voltage drop or for any other reason related to proper circuit operation, the equipment grounding conductor must be increased proportionately.
Bill, Ken, and sometimes Rollie,
Say what you want to, but the Handbook is used to find the INTENT of the NEC by knowledgeable inspectors and experts, heck, WHEN CONVENIENT FOR YOU ... you guys have also tried to use the Handbook to make the code support you ... and now you are trying to degrade the Handbook because IT DOES NOT support your opinion.
Note to Bill, Ken, Rollie: You will never again be able to trot out the Handbook as supporting you when it does not say exactly the same thing as the code as you have now just shot it down in your opinion in front of all of us. Beware of trying to use the Handbook to back you in the future.
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11-28-2009, 11:12 AM #55
Re: wire size
Regardless of the intent, the only thing enforceable is what is written in the black and white.
Could you please post where anyone has said anything contradictory to this except yourself in post #16?
Or in post #18
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11-28-2009, 12:37 PM #56
Re: wire size
Gee, Bill never dragged out the handbook in the tape argument. Seems to me like it was a certain inspector reading things into the code language that weren't there - namely a prohibition on tape. Code never prohibited tape, Jerry did - to the point you were a jack legged idiot if you used it. I can assure you the quality of the tape didn't change between the language in the 2008 NEC and the draft of the 2011 NEC. What got to be a problem that needed attention was too many guys like Jerry. That same problems exists here - reading stuff into the code that isn't there.
I'm guilty of lots of stuff, and will be of more, but Jerry doesn't get to add to it at will.
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11-28-2009, 12:48 PM #57
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11-28-2009, 01:06 PM #58
Re: wire size
Bill,
Let me get this straight ...
1) You were against the wording of the code because you had another opinion. (Regarding the tape not being acceptable for permanent marking because tape is not permanent, the tape manufacturers even acknowledged that, and I posted that too.)
2) You are for the wording of the code because you have the same opinion. (Regarding this upsizing issue.)
So ... you are ... or are not ... (I can't keep track of your flip-flopping) ... a supporter of the WORDING of the code, and to heck with the Handbook?
Please think your answer over carefully as you will be saying that some of your posts were wrong ... which ever answer you give.
See, with me, I go by the wording of the code, and when the wording changes, as it will be regarding the tape, then I change too.
By the way, the reason the code is changing is, yes, IS changing is because of people like me who actually read the code and go by what it says. And now you are trying to make that into a bad thing? Sheesh.
By the way, the wording of the code regarding the upsizing issue DOES support what I am saying, and what the Handbook is saying, and, yes, it seems that it will take yet another code change to make it so people like Bill, Ken, and others also understand it. Maybe they will simply put in a definition of "upsizing/upsize" to clarify that it is based on "Gosh, I need to UPSIZE this wire for ... (voltage drop or some other reason to make the circuit operate properly)." and that it is not "upsizing" when one simply chooses to use a larger size wire "just because" and there is no compelling reason to do so for the operation of the circuit.
But, here we are again, back to debating the INTENT of the code, which is some think YOU bring up frequently when the code WORDING does not state what you want it to state, and then out comes the Handbook or something to try to support something other than what the WORDING of the code says.
Bill, it is best if you simply chalk this one up in the 'lost' column and then throw your Handbook away.
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11-28-2009, 01:46 PM #59
Re: wire size
See, with me, I go by the wording of the code, and when the wording changes, as it will be regarding the tape, then I change too.
No Jerry, you go with whatever you think will keep you from looking like a fool and don't always succeed.
No doubt in my mind you know some of your business pretty well. The rest you seem to make up as you go along.
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11-28-2009, 03:19 PM #60
Re: wire size
Regarding the tape issue, this sounds more like what myself and others here have said that tape is "an other effective means" to identify a conductors purpose. This does not seem to support your previous view that tape was not a compliant method since it is now apparently going to be specifically mentioned as an approved means.
Sounds more like an example of needing to spell things out for people that don't or can't understand the nuances of a complex document or without experience in the field. Just another example of dumbing things down instead of the bar being raised through education and competent teaching.
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11-28-2009, 03:35 PM #61
Re: wire size
While the Handbook is written by extremely knowledgeable people it is only the authors opinion as to the intent of the CMP's. There is also more than one Handbook. Suppose the opinions expressed differed between authors. Who is now the correct interpretation?
The wide distribution of the Handbook just makes it an easier reference than asking for an opinion from the NFPA and is available in much more timely manner.
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11-29-2009, 06:08 PM #62
Re: wire size
Mr. Peck-
First you are quite incorrect in saying I am troting out the handbook for support of my posts!
I have made 2 yes thats TWO - 2 references to the handbook .
#1 - post number 29 I referenced the handbook by stating The hanbook has a nice example of .......
Now gee thats not using the handbook trying support statements of code, just pointing out there is an example for reference or clarification of what I was posting - the same as commentary
#2 - Post # 50 - I referenced YOUR cutting and pasting of commentary from the code book as a code reference.
As far as me using the handbook and it NOT being the code, might want to look into that closer. I use the 2008 NEC Handbook, Published by the NFPA. It contains the entire text of the NEC, word for word, plus commentary which is clearly identified. (I know the difference between commentary and the code)
Next time you wish to accuse get the facts straight
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11-29-2009, 06:58 PM #63
Re: wire size
I have never used the NEC Handbook in support of a post, as I do not even own a current or near current edition, & am quite aware that not a bloody thing in the handbook is enforcable, simply a opinion of the author(s).
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11-29-2009, 08:13 PM #64
Re: wire size
JP: (1) When was this revelation? You were still carring on about this on 8/20/09 continuing to claim that painting was the only effective permanent means! I pointed out to you IN THE NEC (NOT the handbook) where permanent means was defined as taping for identification, using ADHESIVE LABELS, TAGING OR OTHER permanent means.
See: http://www.inspectionnews.net/home_i...html#post89241
See: http://www.inspectionnews.net/home_i...html#post97486
JP: (2) The Handbook is NOT consensus developed, is NOT written by the CMPs it is compiled by the editiors and is NOT to be used to determine the INTENT of the NEC. Try reading the introduction, it specifically warns AGAINST what you are now asserting (regarding the use of the Handbook).
BK: (3) We don't have to look to the "handbook", we can find it in the CODE itself AND the LISTINGS for the TAPE itself.
I'm quite tired of these "king of the hill" "last word" and these edicts from the self-proclaimed super duper code inspector/litigation consultant wannabe. You never admit you don't have a leg to stand on, or when you're just plain obviously and outright wrong. Twist warp and be whatever. Those that know, know when you've placed your foot and mouth where the thumb is; most don't BOTHER reading through to see when you totally hang yourself. Sadly those that don't can't tell your head is up your backside or when you're being otherwise creative with a lower orifice.
Last edited by H.G. Watson, Sr.; 11-29-2009 at 08:38 PM.
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11-29-2009, 08:30 PM #65
Re: wire size
H.G.,
So, then, you are quite tired of yourself?
Sounds like the same thing others have been saying about you and your posts recently.
I am delaying responding with additional posts about the "upsizing" issue until I receive a response back from my inquiry to the NFPA about it, which I will post here.
It will either show:
1) That I am correct and you ... along with Bill and Ken are wrong, or
2) That I am wrong and that Bill and Ken are correct.
Either way, I have asked the question of NFPA and will post their response.
While I fully expect the response to be the same as the Handbook, I will post the response WHICHEVER WAY IT COME BACK.
If I am wrong, I am wrong.
If I am not wrong, then you are (as you seem to have chimed in and sided with Bill and Ken).
We shall see who is correct and I will post it here for all to see ... like it or not.
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