Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
I see in the specs lots of times that it says solid for #10 or smaller and stranded for larger than #10. Why is that?
Solid/stranded
- Thread starter Alwayslearningelec
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Also, have you ever tried to pull a #8 solid in a conduit. Well if you have try a #4 or #2 never mind 3/0 :grin::grin:
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
The question is really why do they spec stranded for #10 and smaller? I really am not sure. I know EC's like it because it is easier to pull but not sure why it is speced.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
kwired
Electron manager
- Location
- NE Nebraska
That is irrelevant to the OP question. It does not even mention anything about conductors smaller than #8.
Because some EE specced it once, and they simply copy specs from one job to the next. So far, no one has called the EE to complain, so it keeps getting copied. You don't think they type those 4-volume spec manuals from scratch, do you?
kwired
Electron manager
- Location
- NE Nebraska
Most of the time solid is what I see specified for small conductors, and that is what the OP is asking about.
kwired
Electron manager
- Location
- NE Nebraska
I never ever see specifications for things that do not even apply to the project on the prints.:roll:
macmikeman
Senior Member
- Location
- Planet macmikeman
Anybody got any powdered soapstone I can borrow? I see that one all the stinking time....
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
Here is some interesting info. I hope it is accurate.
Great article, thanks.
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
Boiler plate, boiler plate
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Yes- I meant to write larger than #10. Thanks.
charlietuna
Senior Member
Using solid on smaller wire sizes is specified by engineers who believe that stranded wire can be damaged in the pulling process causing the wire to stretch and the conductor diameter to shrink reducing it's amperage carrying capability. Myself, i like the installation process of solid wire up thru #12 .
kwired
Electron manager
- Location
- NE Nebraska
Re read the OP. He is asking why engineers often specify solid conductors for #10 and smaller. 310.3 does not even address these conductors it states #8 and larger shall be stranded.
I don't know why they specify this - it is not an NEC requirement but strictly a design issue. Maybe they have a reason maybe they have always been taught that that way is better but really do not know if or why it is better.
kwired
Electron manager
- Location
- NE Nebraska
How much harder does one have to pull to start stretching the conductor? They both have the same cross sectional area. The quality of material used to make the conductors likely will have a bigger impact on how easily it will stretch at same pulling force.
Stranded conductors often times pull easier than solid conductors so there would not need to be as much pulling force.
Still seems to me that it does not matter.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
There are many reasons why things get put in specs. A few that come to mind.
1. It got added to the boiler plate because on a single job 30 years ago, it made a difference. Now no one that is still around knows why it was put in the spec, but they are afraid to take it out.
2. The end user expressed a preference.
3. There is actually a good reason for it.
If I write a spec it says stranded, except for a few special circumstances. But, I am reasonable about such things.
jmellc
Senior Member
- Location
- Durham, NC
- Occupation
- Facility Maintenance Tech. Licensed Electrician
The only advantages I see to solid wire are that is is slightly easier to make joints in and it fits into device clamps or screws properly. But stranded pulls much more easily, less stress on the wire. It also packs into boxes more easily.
The bit of extra trouble is worth it. All devices should be made with clamps to handle solid or stranded.
The bit of extra trouble is worth it. All devices should be made with clamps to handle solid or stranded.
It may have come about over the use of stranded when connecting to a switch or receptacle. Possibly too many problems arising from people not willing to use proper care and methods of wiring, allowing the connections to have strands sticking out from them.
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