Cubic inch space

[Josesaucedo]

Does any body know why the National Fire Protection Agency (NFPA) require that a certain amount of " cubic inch space" be allowed for conductors in a junction, receptacle, metallic or nonmetallic box?

Thanks.

 

[celtic]

Re: Cubic inch space

Does any body know why the National Fire Protection Agency (NFPA) require that a certain amount of " cubic inch space" be allowed for conductors in a junction, receptacle, metallic or nonmetallic box?

Thanks.

Considering each wire, clamp or device will occupy space(cubic inches) within said junction, receptacle, metallic or nonmetallic box - how else would you determine that there is too much wire in the box?

 

[ceknight]

Re: Cubic inch space

Does any body know why the National Fire Protection Agency (NFPA) require that a certain amount of " cubic inch space" be allowed for conductors in a junction, receptacle, metallic or nonmetallic box?

I think it's because we never quite got our collective American brain wrapped around the metric system.

 

[richard pando]

Have you ever worked in a "J" box with far so many wires in it you could hardly touch or wiggle them in the box without scraping the insulation and shorting them out? I did today. It made me wonder why table 314.16(a) was so far from this person's mind when he/she did the job. It's for "elbow" room for the wire and any device in the box. it makes a lot of sense to me.
And the code will be all metric one day soon. Let's get used to it.

Richard

 

[infinity]

And the code will be all metric one day soon. Let's get used to it

Let's hope not.

 

[allenwayne]

Have you ever worked in a "J" box with far so many wires in it you could hardly touch or wiggle them in the box without scraping the insulation and shorting them out? I did today. It made me wonder why table 314.16(a) was so far from this person's mind when he/she did the job. It's for "elbow" room for the wire and any device in the box. it makes a lot of sense to me.
And the code will be all metric one day soon. Let's get used to it.

Richard

If they were in a 4 sq.I just get a stack of box extensions,leave the wire standing straight up add extensions till the wire is covered and blank it off.

INSPECTOR - How many extensions are you allowed to use allowed to use?

ANSWER - My limit is six

 

[JohnJ0906]

If they were in a 4 sq.I just get a stack of box extensions,leave the wire standing straight up add extensions till the wire is covered and blank it off.

INSPECTOR - How many extensions are you allowed to use allowed to use?

ANSWER - My limit is six

Just remember 300.14 for the next guy!:smile:

 

[tallgirl]

And the code will be all metric one day soon. Let's get used to it.

Hahahahahahaha! That's funny!

I remember back in the 70's when we were being taught metric in school because some day we'd go metric. Well, we've still not gone metric. And it's an entirely different MILLENIUM.

 

[Bob NH]

I remember back in the 70's when we were being taught metric in school because some day we'd go metric. Well, we've still not gone metric. And it's an entirely different MILLENIUM.

When the Air Force awarded the contract for the MX (Peacekeeper) missile in 1979, they had a requirement that the metric system be used. They junked that when contractors pointed out that aerospace-quality metric fasteners and similar components were simply not available. AN, MS and NAS fasteners and components were the world "gold standard" for assured quality and strength, and forcing metric would have increased weight and cost. The National Aerospace Standard (NAS) has now been supplemented by NASM which is National Aerospace Standard Metric.

 

[FNCnca]

And the code will be all metric one day soon. Let's get used to it.

Richard

I was told by an instructor from TMK and Assoc. that NEC would go "all" metric in 2011.

 

[don_resqcapt19]

I was told by an instructor from TMK and Assoc. that NEC would go "all" metric in 2011.

I doubt it...if they would do that, I would expect that a lot of the AHJs would not adopt the code. While we should use the metric system, we don't and that would make the code unusable for many.
Don

 

[infinity]

I doubt it...if they would do that, I would expect that a lot of the AHJs would not adopt the code. While we should use the metric system, we don't and that would make the code unusable for many.
Don

I agree. This is a step in the wrong direction.

 

[richard pando]

I wouldn't doubt it. If you look at the transitional progress it's made since the early 80s when the metric system was first introduced, one can see it could happen.