conduit fill

[david cunningham]

on conduit fill i have different enspectors telling me different things.
one says that you only count ungreunded conductors (power) for fill requirements.
one says that you count ungrounded (power) grounded (netrual) and all grounded (ground) conducters as 1.
one says that you count all conductors.
which is right
i work in areas that have appointed inspectors or no inspectors at all. these are villiges of less than 1500 peopleor rual areas. buliding departments are part time. i always try to keep inspectors happy but on pccasions i have ask for waivers of liability from the inspectors when they want somthing realy stupid.
david cunningham

 

[480sparky]

The guy who says they all count wins. Note 3 to Table 9.
They may be getting confused with the derating rules.
As for the guy who says all the hots, neutrals and ground count as one, well, ask him how to calculate his one conductor if they're different sizes. Then have him pull in a 200a 3-phase panel (four 3/0s and a 6 ground according to him would count as one 3/0 = 0.2679in?) in a 1" EMT (0.346in? by Table 4, 40% fill).

BTW.... Welcome!

 

[infinity]

It's called "conduit fill". If it fills the conduit it counts. The only rule relaxation comes for nipples 24" or less in length.

 

[raider1]

one says that you only count ungreunded conductors (power) for fill requirements.

This inspector is probably confusing the derating requirements of 310.15(B)(2) which require you to only count the current carrying conductors.

one says that you count ungrounded (power) grounded (netrual) and all grounded (ground) conducters as 1.

This inspector seems to be confusing conduit fill with box fill from 314.16(B). 314.16(B)(5) allows you to only count the largest single equipment grounding conductor, when multiple equipment grounds are installed in a box.

one says that you count all conductors.

This inspector has it correct. I agree with both infinity and 480sparky.

Chris

 

[celtic]

I agree with both infinity and 480sparky.

Chris

..and I agree with raider1

 

[quogueelectric]

conduit fill

and I agree with Celtic.

 

[fredspence1]

314.16

314.16

Hi David

Here is a summary based on the text of the NEC and NECH:

Conductors that originate outside box,
One for each conductor at the
actual conductor size.

Conductors that pass through box without splice or connection (*less than 12 in. in total length)
One for each conductor at the
actual conductor size.

*Conductors 12 in. or greater that are looped and unbroken (see 300.15 for exact measurement),
Two for a single (entire) unbroken conductor at the
actual conductor size.

Conductors that originate within box and do not leave box,
None (these conductors not counted).

Fixture conductors [per 314.16(B)(1), Exception]
None (these conductors not counted).

Internal cable clamps (one or more),
One only at the largest AWG.

Support fittings (such as fixture studs, hickeys),
One for each type of support fitting based on the
largest-sized conductor present.

Devices (such as receptacles, switches)
Two for each yoke or mounting strap based on the
largest-sized conductor connected to device or equipment.

Equipment grounding conductor (one or more),
one only based on the
largest equipment grounding conductor present.

Isolated equipment grounding conductor (one or more) [see 250.146(D)]
One only based on the
largest isolated and insulated equipment grounding conductor present.

Best regards,

Fred Spence

 

[jscottelwood]

fill

fill

and remember...if you have a seal, it drops to 25%...(just putting in my $.02 worth) I fabricate and assemble nothing but "Class" (Class I, that is...):grin:

 

[infinity]

and remember...if you have a seal, it drops to 25%...(just putting in my $.02 worth) I fabricate and assemble nothing but "Class" (Class I, that is...):grin:

There are seals that are rated for 40% fill. You might just have to order them that way.

 

[cadpoint]

Lol, this is one of those forum posts that just one just has to agree with till Fred posted...

Causing me to re-reading orginal it struck me. Before it was OK, yes, do this, yes don't do that, and what are they trying to Calculate, Thanks Fred ...:roll: & Yes I agree with everyone... (where applied and to da code)
Ode to 05' ...