Romex into the panel with conduit.

Status
Not open for further replies.
Adamjamma said:
Ok..thanks. Still confused but think I am starting to understand... so using a conduit or pipe as a bushing but longer is not ok for this product but, running a trough or a three inch conduit from one panel to a pull box or another panel is ok... running Romex in it allowed.. because it is a raceway not just a sleeve
Click to expand...

generally speaking, using 'open conduit' as a protective sleeve w/o terminating it disqualifies most raceway concerns Adam

~RJ~
 
my home in Jamaica has some 65 foot home runs but most are less than 18 feet. Longest run in fact is for the run from the meter to the panel, as local authority says panel must be in hallway on interior wall , on main floor, which means from the meter to the first ninety sweep is twelve feet, from there to second sweep is thirty eight feet , and then twenty two feet to breaker panel. Because of distance have been thinking seriously about mounting a disconnect switch on the inside of the retaining wall around five feet seven feet from bend... All because road height is so high compared to building areas. Plus, they will not allow main panel in basement, even if sub panel on main floor... Basement must have sub panel run from main panel, and be on a separate conduit.
Love the problems of Jamaica....
but none of my runs are longer than 100 feet unless you count the total circuit lengths..lol...
 
The panel in my house is in the basement roughly in center of the house. I don't know how long the longest home run is, but would bet none of them are over 50-60 feet.

The 10 feet/10% rule sort of don't make a lot of sense to me, but it is what it is. Is conductor 100 feet away going to sink enough heat to have an impact? If so then I guess the rule is fine.
 
kwired said:
The panel in my house is in the basement roughly in center of the house. I don't know how long the longest home run is, but would bet none of them are over 50-60 feet.

.
Click to expand...

310.15 A 2 and it's ex address the entire circuit kwired


~RJ~
 
romex jockey said:
310.15 A 2 and it's ex address the entire circuit kwired


~RJ~
Click to expand...
I can see it interpreted that way. I honestly don't know what the intent is here. Doesn't make sense to me - they about have to be considering heat sinking effects of conductors beyond said transition point, but put a switch within a few feet of that transition point and then 200 feet of conductor beyond that switch. Does the switch transfer the same heat beyond as would happen with no switch? Even if just plain conductor for 100 feet, are you really going to see a difference at said transition point vs if there were only 75 feet of conductor?

I just don't get how they come up with this rule.
 
kwired said:
I just don't get how they come up with this rule.
Click to expand...

Myopic UL studies for cu sales kwire

for ex, take 334.80 , which excludes 310.15(A)(2), Ex , but is ok with table 310.15(B)(3)(a)

it's like saying a 30 circuit panel is constantly pulling 400 amps

~RJ~
 
readydave8 said:
65 circuits?
Click to expand...
No, a few, well five, circuits are around 65 feet from breaker box to first outlet on first floor. Second floor has four such circuits. None on third floor like that, but one in basement and that one is for a pressure pump so put in a 1-1/2 inch conduit as have not yet bought the pressure pump...lol...still hoping to buy one that is dc..

most circuits are simple ten to fifteen feet from outlet to outlet.. conduits make it harder to run as local electrician ran everything into either deck or floor castings, then either up or down the wall... no horizontal runs... so if an outlet is four feet away you figure ten feet conduit..lol.
 
kwired said:
Huh?
Click to expand...

Another code conundrum for another day kwired

I'll just leave it that how and why we derate in throughout the NEC is not universally applicable, and sometimes exist on stand alone substaintiation(s)

For ex, iirc, the 30CC rule is 200CC's in the CEC , maybe more troffers run cooler up there?

~RJ~
 
so, in a 2 inch by 2 inch floor trough, do we use the fill numbers for 2 inch conduit? Stuff is confusing to figure out... The 20CC number - is that for any size conduit? So if you have a three inch conduit carrying 14 g wire you only put 20 CC in it?

Not that I am actually going to do so, just that I am trying to figure out if I understand the stuff yet because I am confusing myself...
 
Adamjamma said:
so, in a 2 inch by 2 inch floor trough, do we use the fill numbers for 2 inch conduit? Stuff is confusing to figure out... The 20CC number - is that for any size conduit? So if you have a three inch conduit carrying 14 g wire you only put 20 CC in it?
Click to expand...

What's a floor trough?

I think that he said "200CC" not 20. For the record the proper abbreviation is CCC's for current carrying condcutors.
 
ok, thank you...
Floor trough..metal box with cover in floor for running cables, with wall trough or raceway... for up a wall..floor trough cover usually hinged.. and has knockouts, at least the ones I used... Put in place, run conduits, fill with newsprint just in case concrete guys are stupid, and let concrete be poured... Easier in some ways to running individual conduits...
Used to run them in between joists in Iron Works for running the data and telephone cables in...

But, so far, mainly use 1 inch or 3/4 inch conduit in my concrete runs...lol..
 
romex jockey said:
Another code conundrum for another day kwired

I'll just leave it that how and why we derate in throughout the NEC is not universally applicable, and sometimes exist on stand alone substaintiation(s)

For ex, iirc, the 30CC rule is 200CC's in the CEC , maybe more troffers run cooler up there?

~RJ~
Click to expand...
I sort of conceded to this long time ago - not everything makes sense. I also understand that it is hard to write a set of rules that cover every possibility and they have to settle on one size fits all to some extent.
 
Adamjamma said:
ok, thank you...
Floor trough..metal box with cover in floor for running cables, with wall trough or raceway... for up a wall..floor trough cover usually hinged.. and has knockouts, at least the ones I used... Put in place, run conduits, fill with newsprint just in case concrete guys are stupid, and let concrete be poured... Easier in some ways to running individual conduits...
Used to run them in between joists in Iron Works for running the data and telephone cables in...

But, so far, mainly use 1 inch or 3/4 inch conduit in my concrete runs...lol..
Click to expand...
What you are describing would likely be covered by NEC art 376 - metal wireways.

Fill is not supposed to exceed 20 percent of cross sectional area. 2 x 2 square is not same area as 2 inch round, so raceway fill tables are useless here. 2 x 2 is four square inches and you can fill to 20% of that.

You can have up to 30 CCC's without applying ampacity adjustments. Go over 30 CCC's and you likely need to increase conductor sizes in many instances.
 
Status
Not open for further replies.
Top