What? Overcrowded Conduit or Tubing (Raceway)!

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#1

Originally Posted By: jtedesco
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Question:


The number of wires (conductors) in these conduits or tubing (they are not cables) exceed the permitted fill, which is 40% of the ID.

Let's say that the original installer limited the number to the permitted amount, so as not to exceed that figure, and then the next homeowner decides to pull a few more wires (conductors) into the existing conduits or tubing (actually we can say raceway too) and decides to supply a couple of loads that are considered as heavy loads! AC's, etc.

How will the visual inspection read?

I am really interested in seeing the answers from a Home Inspector here and not from the "Code Scholars" who know exactly what I am getting at!

I believe that the SOP is a very basic beginning to an electrical inspection and wonder just how far some can go when it comes to items that are not included in that list. Don't you agree?

How many Hi's here would be willing to have a "Code Scholar" follow along a second time, after their report of the "electrical safety items" is included in the list to be downloaded or read by the seller?

I don't want to start any contests here, so please be cool, OK and we can have some fun and maybe, just maybe we can all learn something. ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif)



Photo Courtesy: Randy

--
Joe Tedesco, NEC Consultant

www.nachi.org/tedescobook.htm

#2

Originally Posted By: lfranklin
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I’ll bite.


First 40% fill. Does that mean that over half of that little pipe needs to be open.


Now with two #12 Romex wire in a half inch conduit probably will fill it up. Why do they allow Romex in conduit in residential and not commercial. Or that what I’v heard.


Is the 40% to allow the wire room to disperse heat. Overcrowding in a conduct is sort of like bundling the wire.


The report would read different ways depending on what was visible but would end up with…should be further evaluated by an electrician of your choice.

#3

Originally Posted By: psabados
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Quote:
I believe that the SOP is a very basic beginning to an electrical inspection and wonder just how far some can go when it comes to items that are not included in that list. Don't you agree?


The HI SOP is very basic. If one is not a Licensed Electrician, trying to overstep those bounds will likely cause very serious trouble. When in doubt, defer to the qualified trade, when out of the scope, defer to the qualified trade.

Now if I saw that same installation in a residential dwelling I would have all kinds of warning bells going off in my brain. (Stranded wiring, custom trough, conduits, not your typical residential install).

Off the record and only in my head

From past experience, this looks like a view of a wire trough that has been custom drilled to receive the conduit. The wires in the extreme right conduit and the second from the left look identical. Sort of looks like a wiring system for a typical C-store. If conductors are circuits for cooler or vending machines, that conduit is going to be very hot.

Look at and report on the items of the SOP, report the defects and refer repairs and evaluation outside of normal scope to licensed, qualified electrician.

My opinion and my butt protection, any more information puts me into a handyman category and we know how the sparkies feel about that! ![icon_biggrin.gif](upload://iKNGSw3qcRIEmXySa8gItY6Gczg.gif)

Paul
#4

Originally Posted By: jmyers
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Joe T,


I would write it up just as I see it, overcrowding. I of course am assuming that when you said "code scholars", you were not referring to me. ![icon_cool.gif](upload://oPnLkqdJc33Dyf2uA3TQwRkfhwd.gif)

Don't the conductors all have to be the same size?

Joe Myers

#5

Originally Posted By: dbozek
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Joe T…Is there more than 9 current carrying conductors in that one conduit? Now I really stirred things up. icon_lol.gif

–
You cannot help men permanently by doing for them what they should and could do for themselves. Abraham Lincoln

#6

Originally Posted By: dbozek
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If anyone is interested…I have the formula for figuring out conduit fill. It’s rather simple to do but then I reckon a HI would not need it. But if your curious…email me. icon_wink.gif

–
You cannot help men permanently by doing for them what they should and could do for themselves. Abraham Lincoln

#7

Originally Posted By: jtedesco
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Dennis:


Sure looks like even more that 9! Maybe between 10-20? The other reason for the limitation on fill is the wire pulling strain and although 4 - 90 degree bends are permitted between pull points, that too is another reason.

Please explain the fill stuff and please post the formula you mentioned here.

Or you could look here too:

http://wescalc.wescodirect.com/

![icon_biggrin.gif](upload://iKNGSw3qcRIEmXySa8gItY6Gczg.gif)

--
Joe Tedesco, NEC Consultant

www.nachi.org/tedescobook.htm

#8

Originally Posted By: Greg Fretwell
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How long were these raceways, if they are less than 24" the nipple rule applies (60% fill). chapter 9 table 1


There is also an ugly exception in 312.5 that people think allows them to stuff a raceway “sleeve” with non-metalic cables but you still need to use the fill table.


If you use a strict reading of “fill” you might not be able to put one 12ga romex in a 1/2" pipe. You have to compute a circular conductor based on the widest dimension of the cable. Depending on the construction of the cable you might be able to get one in (53% fill rule) but you certainly could never get 2 in (31% fill rule).

#9

Originally Posted By: dbozek
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Gee Joe T thats too easy icon_lol.gif

–
You cannot help men permanently by doing for them what they should and could do for themselves. Abraham Lincoln

#10

Originally Posted By: Blaine Wiley
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I don’t think I have ever seen that type of installation in a residential home inspection! I would do as Paul said. Refer to a qualified licensed sparky.

#11

Originally Posted By: jtedesco
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Might have been in a Commercial Occupancy, or maybe even in another State, like California where is was common to use “raceways” to wire buildings and branch circuits before NM cables were used where permitted.


I am adding these types of questions for those who may want to broaden there knowledge, and for those who may even want to become a "Certified One and Two Family Electrical Inspector. www.iaei.org

I invited Greg here, and he was involved in an internet training effort many years ago that gave him the knowledge to get that IAEI Certification and more!

Welcome Greg! ![icon_biggrin.gif](upload://iKNGSw3qcRIEmXySa8gItY6Gczg.gif) ![icon_biggrin.gif](upload://iKNGSw3qcRIEmXySa8gItY6Gczg.gif)

--
Joe Tedesco, NEC Consultant

www.nachi.org/tedescobook.htm

#12

Originally Posted By: dbozek
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I run emt and even rigid in houses all the time. Looks neater and more professional. Can be a bit difficult at times though depending on how busy the joist space is.

–
You cannot help men permanently by doing for them what they should and could do for themselves. Abraham Lincoln

#13

Originally Posted By: Bob Badger
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dbozek wrote:
I run emt and even rigid in houses all the time.


Rigid? ![icon_eek.gif](upload://yuxgmvDDEGIQPAyP9sRnK0D0CCY.gif)

Do your customers want the added expense of rigid or EMT just so you can look at the pretty raceways when you are done?

--
Bob (AKA iwire)
ECN Discussion Forums
Mike Holt Code Forum
#14

Originally Posted By: dbozek
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yup rigid…steel even…but then that was a rare instance…and the house was 55,000 sq feet. Normally it is just emt.

–
You cannot help men permanently by doing for them what they should and could do for themselves. Abraham Lincoln

#15

Originally Posted By: Bob Badger
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But still I ask, do your customers want to pay extra money just so you would like the look of the job? icon_rolleyes.gif


Good for you if they do.

--
Bob (AKA iwire)
ECN Discussion Forums
Mike Holt Code Forum

#16

Originally Posted By: dbozek
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I always offer options and believe me when that customer specified rigid I offered many options. I never sell anything the customer doesn’t need either. I explain to the customer what needs to be repaired, why it needs to be repaired and how it can be repaired. I tell them…lookie here…rigid steel pipe is outrageous right now but I can do the same install in emt or even mc. I let them make the choice. If they want rigid…I give them rigid along with my chiropractic bill…They are either making that pipe thicker or I am getting older and weaker.

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You cannot help men permanently by doing for them what they should and could do for themselves. Abraham Lincoln

#17

Originally Posted By: Mike Parks
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How popular do you think that I would be with this sparky if I made him add bushings to this ‘set-up’?


Mike P.

#18

Originally Posted By: lfranklin
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Mike you would be real popular. So popular they would give some extra names icon_lol.gif icon_lol.gif icon_lol.gif


Are the bushing required

#19

Originally Posted By: Mike Parks
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Larry


I am still looking into this. I am getting conflicting information on this.

Mike P.

#20

Originally Posted By: dbozek
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See 300.4 (f) Typically bushings would not be required for the size of the wire used in this thread. Larger wire from 4 ga on up would require such protection. In the case of a concentric knockout as well, grounding type bushings would be required as well, especially if flex is run.

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You cannot help men permanently by doing for them what they should and could do for themselves. Abraham Lincoln