NM usage non usage question.

[ritelec]

Reading through the permitted and not permitted usage of nm.........

Did the article about a third or half the basement being above ground level leave?

I will be doing some work in a single family... 1/2 basement is above ground.. 1st and 2nd floors, and attic is somewhat finished.
The way I see it nm is permitted for use. Correct me if I'm wrong please.

Also 334........ is that for nm-b also? whats the b for?

Also also......protect from physical damage, 334.15 (B)......Schedule 80 pvc?????? Schedule 40 is not permitted???

Also also also... supports.......12" to a box ..... looks to me that thats for all boxes, metal or plastic.....did they get rid of the 8" to plastic box
with no clamp or connector?

Thank you.

 

[Dennis Alwon]

Not sure of your reference to 1/2 below grade.

NM is NMB. I don't know what the B is other than it was designated back when NM became 90C

 

[Dennis Alwon]

look at 314.17(C) exception

 

[GoldDigger]

Not sure of your reference to 1/2 below grade.

NM is NMB. I don't know what the B is other than it was designated back when NM became 90C

The question, I think, is how much has to be below grade (level or on a hillside) to make the difference between a ground floor and a basement.

Outside the US, NM (no B) is still available and usable with the lower temperature rating, AFAIK.

 

[Dennis Alwon]

The question, I think, is how much has to be below grade (level or on a hillside) to make the difference between a ground floor and a basement.

Outside the US, NM (no B) is still available and usable with the lower temperature rating, AFAIK.

I don't think it makes a difference. I could tack wires up on a first floor exposed as long as it is protected. Not sure what the issue is specifically

 

[Gregg Harris]

STORY ABOVE GRADE PLANE. Any story having its finished floor surface entirely above grade plane, except that a basement shall be considered as a story above grade plane where the finished surface of the floor above the basement meets any one of the following:

1. Is more than 6 feet (1829 mm) above grade plane. 2. Is more than 6 feet (1829 mm) above the finished ground level for more than 50 percent of the total building perimeter. 3. Is more than 12 feet (3658 mm) above the finished ground level at any point.

 

[GoldDigger]

STORY ABOVE GRADE PLANE. Any story having its finished floor surface entirely above grade plane, except that a basement shall be considered as a story above grade plane where the finished surface of the floor above the basement meets any one of the following:

1. Is more than 6 feet (1829 mm) above grade plane. 2. Is more than 6 feet (1829 mm) above the finished ground level for more than 50 percent of the total building perimeter. 3. Is more than 12 feet (3658 mm) above the finished ground level at any point.

Helpful!
So, I guess I could make any basement a story above grade plane by digging and finishing a 12' deep pit next to its perimeter at any point? Even if the bottom of that pit is 6 feet below the basement floor.

 

[ritelec]

I have to look for some older books..but like 15 or 20 yrs ago.......... nm was not allowed in buildings over three stories......and the first level was considered the basement
if 1/3 or 1/2 was above finished grade.........

 

[GoldDigger]

I have to look for some older books..but like 15 or 20 yrs ago.......... nm was not allowed in buildings over three stories......and the first level was considered the basement
if 1/3 or 1/2 was above finished grade.........

If it said three stories above grade plane, then the definition that Gregg Harris posted would be the key.

 

[Gregg Harris]

I have to look for some older books..but like 15 or 20 yrs ago.......... nm was not allowed in buildings over three stories......and the first level was considered the basement
if 1/3 or 1/2 was above finished grade.........

336.4

1993
removed 1996

 

[ritelec]

look at 314.17(C) exception

Nice Dennis. Thank you.

What gives with the protection of said cable
no mention of sch. 40 only sch. 80 ??



And thank you Gregg Harris for finding
that older article.

 

[GoldDigger]

What gives with the protection of said cable
no mention of sch. 40 only sch. 80 ??

Schedule 80 has thicker walls. Kind of similar to EMT versus rigid.

 

[ritelec]

Thanks GoldDigger.......

My question is more in the vain of The schedule 80 being mentioned and not the 40.

I've installed 40 and have seen maybe thousands of installs with 40..........
Were my installs (and all other peoples installs, some inspected, some not) not to code????

Never knew only "80" was permitted.......??? Doesn't sound right.

??? lets say, I have nm.......... I have a run.....I then install a box (or not) and sleeve it in 40. WRONG?
??? lets then say I have nm.... I have a run.....I then install a box and sleeve thhn/thwn in 40. RIGHT?

 

[Gregg Harris]

Thanks GoldDigger.......

My question is more in the vain of The schedule 80 being mentioned and not the 40.

I've installed 40 and have seen maybe thousands of installs with 40..........
Were my installs (and all other peoples installs, some inspected, some not) not to code????

Never knew only "80" was permitted.......??? Doesn't sound right.

??? lets say, I have nm.......... I have a run.....I then install a box (or not) and sleeve it in 40. WRONG?
??? lets then say I have nm.... I have a run.....I then install a box and sleeve thhn/thwn in 40. RIGHT?

Nothing precludes the use of schedule 40, unless it is deemed in an area that is subject to "physical damage"

(B) Protection from Physical Damage. Cable shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, Type RTRC marked with the suffix -XW, or other approved means. Where passing through a floor, the cable shall be enclosed in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, Type RTRC marked with the suffix -XW, or other approved means extending at least 150 mm (6 in.) above the floor.

 

[ritelec]

Nothing precludes the use of schedule 40, unless it is deemed in an area that is subject to "physical damage"

(B) Protection from Physical Damage. Cable shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, Type RTRC marked with the suffix -XW, or other approved means. Where passing through a floor, the cable shall be enclosed in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, Type RTRC marked with the suffix -XW, or other approved means extending at least 150 mm (6 in.) above the floor.

yeah.............wow.............

A switch location in a residential application between two garage doors.........(you know what I mean......and similar.whips down basement walls etc...) sleeved in 40 would not fly???

Guess it would be who's interpreting the physical damage? garden tools and equipment, chinese stars or paperclips.......................driveways, runways, or the battlestar galactica.........

wow.........

OK