Calculating romex diameter
- Thread starter kunzio
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hbiss
EC, Westchester, New York NEC: 2014
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- Hawthorne, New York NEC: 2014
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- EC
Re: Calculating romex diameter
For bend radius, eyeball it. If in doubt make it bigger.
Romex in conduit, well you really don't put NM in conduit (though you could) you only sleeve it. You use the size required for the individual conductors or larger if necessary because of the jacket.
For other types of cable, particularly LV, the manufacturer will give the diameter and have recommendations for conduit fill. Chapter 3 conduit fill does not apply to LV cables.
-Hal
For bend radius, eyeball it. If in doubt make it bigger.
Romex in conduit, well you really don't put NM in conduit (though you could) you only sleeve it. You use the size required for the individual conductors or larger if necessary because of the jacket.
For other types of cable, particularly LV, the manufacturer will give the diameter and have recommendations for conduit fill. Chapter 3 conduit fill does not apply to LV cables.
-Hal
buck33k
Senior Member
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- Washington state and North Carolina
Re: Calculating romex diameter
Kunzio
At the beginning of Chapter 9, see note (9) in notes to tables. This should answer your question.
Kunzio
At the beginning of Chapter 9, see note (9) in notes to tables. This should answer your question.
Re: Calculating romex diameter
Ok, so after reading Chapter 9 Note 9, I measured some 14-2 I have here. I found the diameter to be 3/8"...
Diameter = 3/8" = .375"
Area = .375x.375x3.146 = .4418"sq
Are these directly transferable to Ch 9 Table 8? Are they complete/right? More code references would be nice.
Thanks...
Ok, so after reading Chapter 9 Note 9, I measured some 14-2 I have here. I found the diameter to be 3/8"...
Diameter = 3/8" = .375"
Area = .375x.375x3.146 = .4418"sq
Are these directly transferable to Ch 9 Table 8? Are they complete/right? More code references would be nice.
Thanks...
buck33k
Senior Member
- Location
- Washington state and North Carolina
Re: Calculating romex diameter
Kunzio
I do'nt see how this is directly transferrable to Chapter 9, table 8, but instead would be applied to table 4.
I have had to think about this using a 20"pvc sleeve.
BTW: Area=diameter squared x .7854.(not 3.14) Correct me if I am wrong.
[ August 14, 2004, 02:29 AM: Message edited by: buck33k ]
Kunzio
I do'nt see how this is directly transferrable to Chapter 9, table 8, but instead would be applied to table 4.
I have had to think about this using a 20"pvc sleeve.
BTW: Area=diameter squared x .7854.(not 3.14) Correct me if I am wrong.
[ August 14, 2004, 02:29 AM: Message edited by: buck33k ]
Re: Calculating romex diameter
The reason I ask if it is directly transferable to Ch 9 table 8 is the romex would have nearly the same diameter and area as 1/0. Even using Ch 9 table 4, the area of .1104 (from new calculations below) would only allow one of my 14-2 in 1/2" EMT and two of my 14-2 in a 1" EMT...
Buck33k...I used the Ugly's page 128 formula for "area of a circle" 3.1416 x Radius x Radius...
My original calculation was wrong and the correct Area would be .375"/2=.1875" for Radius
so .1875 x .1875 x 3.1416 =.1104" Area
Does this still look ok?
The reason I ask if it is directly transferable to Ch 9 table 8 is the romex would have nearly the same diameter and area as 1/0. Even using Ch 9 table 4, the area of .1104 (from new calculations below) would only allow one of my 14-2 in 1/2" EMT and two of my 14-2 in a 1" EMT...
Buck33k...I used the Ugly's page 128 formula for "area of a circle" 3.1416 x Radius x Radius...
My original calculation was wrong and the correct Area would be .375"/2=.1875" for Radius
so .1875 x .1875 x 3.1416 =.1104" Area
Does this still look ok?
buck33k
Senior Member
- Location
- Washington state and North Carolina
Re: Calculating romex diameter
.1104 Looks OK to me.
.1104 Looks OK to me.
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