depth
- Thread starter golf4life
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dana1028
Senior Member
- Location
- San Francisco Bay area
Re: depth
Question for Chap. 9 (related to this topic).
Note 9: "a multiconductor cable...shall be treated as a single conductor for calculating percentage conduit fill area..."
1. With respect to the arithmetic, I treat UF as a single conductor and come up with approx. .1256 sq. inches of area (this is for #12 conductor UF).
2. Now - do I still treat the UF as a single conductor when looking at the Tables? i.e. the column for 1 wire allowing 53% fill?
3. or do I now treat the UF as the multi-conductor and use the 'over 2 wires' column allowing 40% fill?
Question for Chap. 9 (related to this topic).
Note 9: "a multiconductor cable...shall be treated as a single conductor for calculating percentage conduit fill area..."
1. With respect to the arithmetic, I treat UF as a single conductor and come up with approx. .1256 sq. inches of area (this is for #12 conductor UF).
2. Now - do I still treat the UF as a single conductor when looking at the Tables? i.e. the column for 1 wire allowing 53% fill?
3. or do I now treat the UF as the multi-conductor and use the 'over 2 wires' column allowing 40% fill?
Re: depth
Dana,
did you look at the second half of note #9, where it says: "the cross-sectional area calculation shall be based on using the major diameter of the ellipse as a circle diameter?
Using "pie-are-square" for the area of a circle, with the radius being 1/2 inch, I figure an area of .785 sq. in.
Then, use the 53% fill for a single conductor, and EMT from table 4, I get 1-1/4 inch pipe.
Earl
Dana,
did you look at the second half of note #9, where it says: "the cross-sectional area calculation shall be based on using the major diameter of the ellipse as a circle diameter?
Using "pie-are-square" for the area of a circle, with the radius being 1/2 inch, I figure an area of .785 sq. in.
Then, use the 53% fill for a single conductor, and EMT from table 4, I get 1-1/4 inch pipe.
Earl
dana1028
Senior Member
- Location
- San Francisco Bay area
Re: depth
thanx earlydean -
...that's what I was trying to figure out....which column to use....so the correct columnm is the 53% column.
BTW...the diameter is close to 1/2", not the radius.....either way, it would appear a 1/2" conduit is too small for UF cable.
[ September 08, 2003, 04:50 PM: Message edited by: dana1028 ]
thanx earlydean -
...that's what I was trying to figure out....which column to use....so the correct columnm is the 53% column.
BTW...the diameter is close to 1/2", not the radius.....either way, it would appear a 1/2" conduit is too small for UF cable.
[ September 08, 2003, 04:50 PM: Message edited by: dana1028 ]
- Location
- Massachusetts
Re: depth
18" deep if no GFCI protection on the circuit.
12" Deep if you follow the rules of column 4 of Table 300.5
I would run at least 3/4" PVC if I was going to put 12/2 UF in it.
18" deep if no GFCI protection on the circuit.
12" Deep if you follow the rules of column 4 of Table 300.5
I will ask why you want to run UF in PVC, if you are running PVC I would suggest using single conductors type THWN in the PVC.
Re: depth
Iwire quote
___________________________________
18" deep if no GFCI protection on the circuit.
_I would run at least 3/4" PVC if I was going to put 12/2 UF in it.
18" deep if no GFCI protection on the circuit.
12" Deep if you follow the rules of column 4 of Table 300.5
__________________________________
Should read
"18" deep if WITH GFCI protection on the circuit."
The 12" depth rule is for locations that will have a concrete cover from 2 to 4 inches of concrete
Golf4life the gfi protection shall be ahead of the 12/2 ckt before it enters the under ground
pvc pipe
If you ran the 12/2 in a trench then you have to go to the 24" depth
A red electrical caution tape must also be install in the trench prior to the final cover
You may need to install a disconnect means
in the garage before feeding the lights and outlets. In your case it can be a simple toggle switch.
I normaly run a 1" and 3/4. with the ok from the homeowner 1" for possible Sub panel, if this is a larger garage. the 3/4 pipe if they want to add
phone-cable or alarm, intercom. Pvc is cheap.
Digging a trench by hand is the toughest part of the job
Iwire quote
___________________________________
18" deep if no GFCI protection on the circuit.
_I would run at least 3/4" PVC if I was going to put 12/2 UF in it.
18" deep if no GFCI protection on the circuit.
12" Deep if you follow the rules of column 4 of Table 300.5
__________________________________
Should read
"18" deep if WITH GFCI protection on the circuit."
The 12" depth rule is for locations that will have a concrete cover from 2 to 4 inches of concrete
Golf4life the gfi protection shall be ahead of the 12/2 ckt before it enters the under ground
pvc pipe
If you ran the 12/2 in a trench then you have to go to the 24" depth
A red electrical caution tape must also be install in the trench prior to the final cover
You may need to install a disconnect means
in the garage before feeding the lights and outlets. In your case it can be a simple toggle switch.
I normaly run a 1" and 3/4. with the ok from the homeowner 1" for possible Sub panel, if this is a larger garage. the 3/4 pipe if they want to add
phone-cable or alarm, intercom. Pvc is cheap.
Digging a trench by hand is the toughest part of the job
- Location
- Massachusetts
Re: depth
Cables or raceways can be just 12" down in this top row and just 6" down "In trench below 50-mm (2-in.) thick concrete or equivalent"
Bob
You should take a look at the top row "All locations not specified below" and column 4.
Cables or raceways can be just 12" down in this top row and just 6" down "In trench below 50-mm (2-in.) thick concrete or equivalent"
Good idea, not an NEC requirement.
Bob
Re: depth
Iwire take a look at 305 (1) 3
Service Conductors, Underground service conductors that are not encased in concrete and that are buried 450 mm (18")or more below grade shall have their location identified by a warning ribbon that is placed in the trench at least 300mm
(12") above the underground installation
Iwire take a look at 305 (1) 3
Service Conductors, Underground service conductors that are not encased in concrete and that are buried 450 mm (18")or more below grade shall have their location identified by a warning ribbon that is placed in the trench at least 300mm
(12") above the underground installation
Re: depth
LOL
I had looked at 300.5
column 3 for nonmetallic raceway,Direct burial no concrete cover is 18"
Column 4 is residential branch ckts 120v or less With gfi protection.
Golf4life is Not going under a building, nor driveway,road. He is useing the pvc pipe as a sleeve so then column 3 must apply
LOL
I had looked at 300.5
column 3 for nonmetallic raceway,Direct burial no concrete cover is 18"
Column 4 is residential branch ckts 120v or less With gfi protection.
Golf4life is Not going under a building, nor driveway,road. He is useing the pvc pipe as a sleeve so then column 3 must apply
- Location
- Massachusetts
Re: depth
As long as this circuit is on a GFCI, column 4 could be used.
Thats why I still say this.
Yes very true, but a 120 volt branch circuit is not service conductors, so it does not apply to this installation, still a good idea though.
Can you explain why you think column 4 does not apply to the circuit we are taking about?
I would think this is a 20 amp circuit as he wants to put it in 1/2" PVC.
As long as this circuit is on a GFCI, column 4 could be used.
Thats why I still say this.
Bob
Re: depth
Iwire I do owe you an apology after rereading
300.5 and Looking at the notes listed
note 4 reads
_________________________________________________
Where one of the wiring method types listed in
Columns 1-3 is used for one of the circuit types in columns 4 and 5, the shallower depth of burial shall be permitted.
________________________________________________
Iwire I do owe you an apology after rereading
300.5 and Looking at the notes listed
note 4 reads
_________________________________________________
Where one of the wiring method types listed in
Columns 1-3 is used for one of the circuit types in columns 4 and 5, the shallower depth of burial shall be permitted.
________________________________________________
- Location
- Massachusetts
Re: depth
Shockare you do not owe me anything, we are all here to learn and I certainly learn things here from the other members.
I have nothing but respect
for people that are not afraid to admit a mistake, I have no respect for those that think they can not be mistaken.
Shoot if I had a dime for all the mistakes I have posted here I might be able to stop working.
Take care and keep on participating.
Bob
Shockare you do not owe me anything, we are all here to learn and I certainly learn things here from the other members.
I have nothing but respect
for people that are not afraid to admit a mistake, I have no respect for those that think they can not be mistaken.Shoot if I had a dime for all the mistakes I have posted here I might be able to stop working.
Take care and keep on participating.
Bob
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