# NEC-2008-310.3 Clarification



## 2Phase-Ground:-) (May 22, 2009)

ARTICLE 310
Conductors for General Wiring

310.1 Scope. This article covers general requirements for
conductors and their type designations, insulations, markings,
mechanical strengths, ampacity ratings, and uses.
These requirements do not apply to conductors that form an
integral part of equipment, such as motors, motor controllers,
and similar equipment, or to conductors specifically
provided for elsewhere in this Code.
FPN: For flexible cords and cables, see Article 400. For
fixture wires, see Article 402.
310.2 Conductors.
(A) Insulated. Conductors shall be insulated.
Exception: Where covered or bare conductors are specifi-
cally permitted elsewhere in this Code.
FPN: See 250.184 for insulation of neutral conductors of a
solidly grounded high-voltage system.
(B) Conductor Material. Conductors in this article shall
be of aluminum, copper-clad aluminum, or copper unless
otherwise specified.
*310.3 Stranded Conductors. Where installed in raceways,*
*conductors of size 8 AWG and larger shall be stranded.*
*Exception: As permitted or required elsewhere in this*
*Code.*​----------
*Does this now mean that we can no longer use 10, 12 and 14 stranded AWG wire in conduit runs?* :confused1: *Are we stuck with solid only???*
Section 330.104 cover MC (Metal Clad)
330.104 Conductors. Conductors shall be of copper, aluminum,
copper-clad aluminum, nickel or nickel-coated
copper, solid or stranded. The minimum conductor size
shall be 18 AWG copper, nickel or nickel-coated copper,
and 12 AWG aluminum or copper-clad aluminum.​And in 330.112A regarding 600V330.112 Insulation. Insulated conductors shall comply
with 330.112(A) or (B).
(A) 600 Volts. Insulated conductors in sizes *18 AWG and
16 AWG* shall be of a type listed in Table 402.3, with a
maximum operating temperature not less than 90°C
(194°F) and as permitted by 725.49. Conductors larger than
16 AWG shall be of a type listed in Table 310.13(A) or of
a type identified for use in Type MC cable.​


----------



## sparkyboys (May 3, 2009)

yeah you can run 10, 12, 14 in conduit runs.


----------



## sparkyboys (May 3, 2009)

yeah you can run 10, 12, 14 stranded in conduit runs.


----------



## RePhase277 (Feb 5, 2008)

It means that #8 and larger has to be stranded when in a conduit. In other words, you can install a solid #10 in a conduit, but you can't install a solid #8 in a conduit.


----------



## 2Phase-Ground:-) (May 22, 2009)

Thank you. When read with a pre-conceived notion of "hey, go find out why 310 says we can no longer use stranded in our runs...". I guess the eyes and mind hunt for what they are expecting.

Again, thank you guys.


----------



## bobkat (Jan 22, 2007)

There is no prohibition against the smaller conductors being solid or stranded. The #8 stranded in conduit rule came about in the early '60s I believe. I have had to rework some older range circuits that were #6 and #8 solid TW in 3/4 & 1" greenfield and that is some brutal pulling after it has been in there 30 or 40 years. The rule is a good one I think.

Another problem I've seen from time to time is wrapping stranded #14 or #12 around the binding screw on devices. While this practice is legal, it takes a bit of skill and patience to make a good clean installation. Leaving a small piece of insulation at the end of the conductor can be helpful.


----------



## cdnelectrician (Mar 14, 2008)

bobkat said:


> There is no prohibition against the smaller conductors being solid or stranded. The #8 stranded in conduit rule came about in the early '60s I believe. I have had to rework some older range circuits that were #6 and #8 solid TW in 3/4 & 1" greenfield and that is some brutal pulling after it has been in there 30 or 40 years. The rule is a good one I think.
> 
> Another problem I've seen from time to time is wrapping stranded #14 or #12 around the binding screw on devices. While this practice is legal, it takes a bit of skill and patience to make a good clean installation. Leaving a small piece of insulation at the end of the conductor can be helpful.


And twist them counter clockwise!


----------

