Stranded versus solid bare Number 6

gswartz

New User
Location
North Carolina
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Solar Project Manager
Just a general question as for grounding when is it more acceptable to use stranded number 6 copper for grounding versus bare number 6 when connecting a solar array to another solar array that may be 4 feet away. Is there any preference or NEC code for that?
 

infinity

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Location
New Jersey
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Journeyman Electrician
I don't know about solar but for a GEC or bonding jumper I will use stranded #6 every time. I have never used solid #6 in almost 35 years of electrical work.
 

infinity

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Location
New Jersey
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Journeyman Electrician
Interesting. I generally use stranded but I hoard scraps of thhn and xhhw so my stranded is also insulated.
Yeah us too, we always use insulated and stranded. I try to use green but I did one time use orange #6 THHN to a ground rod that looked kind of strange running down the foundation into the ground. Might be a regional thing but not many around here use solid.
 

jaggedben

Senior Member
Running a #6 solid in conduit is generally prohibited but is permitted specifically only for bonding solar arrays. So part of the answer to this question is that if it is in conduit and is not for solar arrays, it must be stranded.
 

jaggedben

Senior Member
You have a code reference for that?
For the general prohibition, see 310.3(C) in the 2020 NEC, or 310.106(C) in previous cycles.

For the solar exception, it appears I haven't kept up. It was 690.46 in the 2014 NEC but I can't find a corresponding section in the 2017 or 2020. Moreover, the 2020 removed explicit requirements to follow 250.120(C).

So the answer to the OP's question depends on what code cycle they are on, if they're running it through conduit.
 

Little Bill

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Tennessee NEC:2017
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Electrician
For the general prohibition, see 310.3(C) in the 2020 NEC, or 310.106(C) in previous cycles.

For the solar exception, it appears I haven't kept up. It was 690.46 in the 2014 NEC but I can't find a corresponding section in the 2017 or 2020. Moreover, the 2020 removed explicit requirements to follow 250.120(C).

So the answer to the OP's question depends on what code cycle they are on, if they're running it through conduit.
I can't answer about Solar, but the article 310.106 (2017) is for general wiring. You have to look at 250.64 for GEC. There is no prohibition to using solid #6 in conduit for a GEC. In fact, it's required where subject to physical damage.
 

infinity

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Location
New Jersey
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Journeyman Electrician
I can't answer about Solar, but the article 310.106 (2017) is for general wiring. You have to look at 250.64 for GEC. There is no prohibition to using solid #6 in conduit for a GEC. In fact, it's required where subject to physical damage.
Bill,
310.106(C) says " not specifically permitted or required elsewhere in this Code to be solid" where in 250.64 does it say that the conductor is required to be solid or specifically permitted to be in a raceway?
 

Little Bill

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Tennessee NEC:2017
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Electrician
Bill,
310.106(C) says " not specifically permitted or required elsewhere in this Code to be solid" where in 250.64 does it say that the conductor is required to be solid or specifically permitted to be in a raceway?
I never said it had to be solid, I just said he could be and that it could be in conduit according to 250.64(B)(2)

(2) Exposed to Physical Damage. A 6 AWG or larger copper
or aluminum grounding electrode conductor exposed to physical
damage shall be protected in rigid metal conduit (RMC),
intermediate metal conduit (IMC), rigid polyvinyl chloride
conduit (PVC), reinforced thermosetting resin conduit Type
XW (RTRC-XW), electrical metallic tubing (EMT), or cable
armor.
 

infinity

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Location
New Jersey
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Journeyman Electrician
I never said it had to be solid, I just said he could be and that it could be in conduit according to 250.64(B)(2)
What I'm saying is that it cannot be solid in a raceway if it's #6. There is no specific permission for a #6 solid GEC to be installed in a raceway or a specific requirement that says it must be solid therefore it is prohibited by 310.106(C).
 

Little Bill

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Staff member
Location
Tennessee NEC:2017
Occupation
Electrician
What I'm saying is that it cannot be solid in a raceway if it's #6. There is no specific permission for a #6 solid GEC to be installed in a raceway or a specific requirement that says it must be solid therefore it is prohibited by 310.106(C).
The term I used was "conduit" not "raceway" and it's clearly stated in the section I posted. Nothing there says "no solid" it just says GEC, which can be solid or stranded.
 

infinity

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Location
New Jersey
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Journeyman Electrician
The term I used was "conduit" not "raceway" and it's clearly stated in the section I posted. Nothing there says "no solid" it just says GEC, which can be solid or stranded.
Ok so you're referring to a short piece of conduit being used as a sleeve not pulling a solid #6 in a raceway.
 

infinity

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Location
New Jersey
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Journeyman Electrician
Yes, the OP was about solid or stranded GEC. Jaggedben threw in that solid #6 couldn't be used in conduit. I was just pointing out that it could for a GEC.
Yes, the distinction is the conduit must be being used as a sleeve not a raceway for a solid GEC larger than #10. The NEC does permit #8 solid in a raceway for a wet niche pool light.
 

Dennis Alwon

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Location
Chapel Hill, NC
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Electrical Contractor
I agree #6 solid can be sleeved but not installed in a complete raceway... I got called on it even though it went from an outdoor meter to the indoor panel just inside the wall. It was #4 but same thing.. Bad call in that situation, IMO
 
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