Romex in conduit to panel

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sb1280 said:
There are 880 amps of breakers in the left panel with 200 amp main.
There are 600 amps of breakers in middle panel with 200 amp main.
The right panel is a 100 amp panel feed from the middle panel with about 160 amps of breakers.
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The totals of the breakers don't really mean much.

What are the load calculations for each panel?
 
so really the only issues are:
1. if the panel is surface mounted
2. if the 2" conduit is greater than 18" L but less than 24" L
3. fill

if it complies with the first two then how many 12/2 romex cables can be put in the conduit? Table 1(9) says the cable's cross-sectional measurement (if elliptical, which I think romex would be considered) is used as a diameter and that diameter is used in calculating fill as if it were a round cable with that same diameter. The surface area of a 12/2 romex (assuming a .5" diameter) is 0.1963 sq. in. If the conduit in use is a 2" rigid PVC (I can't see the pics) table 4 says that the 60% fill area (according to table 1(4))is 1.975 sq. in. So, 1.975 divided by 0.1963 equals 10 each 12/2 romex cables in a rigid 2" PVC nipple.
 
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Electron_Sam78 said:
so really the only issues are:
1. if the panel is surface mounted
2. if the 2" conduit is greater than 18" L but less than 24" L
3. fill

.
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Also, see (c) and (d) of the exception to 312.5(C)

Can't tell from the picture if a fitting is provided, and it won't be accessible after sheetrock [(c)]
Also can't tell if the raceway is sealed. [(d)]
 
Followup

Followup

We are under NEC 2005.
The conduit is not sealed.
There is a fitting with bushing at panel.
 
Did anybody notice the two left panels have feeder cables in along with the branch cables. If derating does apply,and IMO it does, what would be the ampere rating of the sub panels then.

If the main panels in the picture are surrounded by a wall structure it is no longer surface mounted. If it was mounted on top of the wall structure it would be surface.IMO
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As I read it these sleeves or nipples are permitted to be between 18" and 10' in length and as sleeves the fill requirements of Table 1 Chapter 9 do not apply. However, for those nipples over 2' the ampacity of the cables within must adjusted by 310.15(B)(2).
I don't understand why they also have to be at least 18" long, but thats what the book says. This guy needs to derate the circuits in the rightmost panel at least, and all of them at worst (if over 2'). In addition he needs bushings at both ends of the nipples, to fasten the cables within 12" of the top of the nipple, to seal the tops of the nipples, and to make sure it is all left exposed. Otherwise he's OK. Right?
 
sb1280 said:
With 40 plus circuits the electrician says, "I don't have enough knockouts. What am I suppose to do?"
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Okay, after having seen more of the pix, I'd have to ask the electrician if he really tried to use the individual KO's, or at least counted cables and holes.

And, yes, he could have run some of the cables down the adjacent wall cavities, through or behind the studs, and up into the bottom of the enclosures.
 
hurk27 said:
Maybe but it don't stop someone from using it;)
ththsmileyjoke.gif
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Guys,
I downloaded it,
pointed my browser to the file,
it jumped right up and worked.
Got to alter it so that the red guy shoots a lightning bolt!

Anyway, the panel "looks" like there are too many Romex cables in the conduit,
and the derating would reduce ampacity,
which was not mentioned by the OP.

:smile:
 
CopperTone said:
- 2 romex wires in one hole - they always will fit -
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Copper,

Are you suggesting that a 5/8" hole through a 2x4 plate
does not have a UL rating
as to how many romex cables can pass through the hole ? :smile:

I have always thought that if the cables were loose,
then they could fit.
 
Mvillines said:
Table 1 Chapter 9 do apply. See 312.5(C)(g)
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312.5(C)(g) says "where installed as conduit or tubing, the allowable cable fill does not exceed that permitted for complete conduit or tubing systems by Table 1 Chapter 9 of this and all applicable notes thereto".

Table 1 Chapter 9 Note (2): Table 1 applies only to complete conduit or tubing systems and is not intended to apply to sections of conduit or tubing used to protect exposed wiring from physical damage."
I would argue that an 18" to 24" "nipple" or "sleeve" does not count as a conduit system and is therefore excluded from applying the conduit fill rules of Table 1 Chapter 9.
Not that I would suggest cramming them full, but I believe them exempted on purpose by the wording of 312.5(C)(g). If they were connected to a trough or box then they would not be exempted because they may be interpreted as "complete systems".
 
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312.5(C) Exception sets the stage when cables are not required to be secured to the cabinet, etc.
Subsections (a) through (f) specifically states raceways, which could be other than conduit or tubing. Subsection (g) specifically states where conduit or tubing is used to comply with the exception the conduit fill will be applicable.
 
I don't think the stubs in the pictures are allowed at all because they are not surface mounted. If they were surface mounted then no fill restrictions and no derating if under
2' long.
 
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