Conduit Entry And Distance Between Raceways

[William K Hicks]

I am just looking for some other opinions as far as when coming into a pull box on the outside of a building and through the wall into a switchboad. The conduits come up into the bottom of the box and leave the back of the box. Code staes that the distance between raceways for angle pulls needs to be 6 times the trade size of the conduit. Although the exception states that if a raceway enters in a wall of the box where there is a removable cover then the distance from the entry to the cover can be determined by using table 312.6A. My question is does the exception alow you to not have to use the 6 times the trade size of the conduit between raceways. We have a limitted distance as far as entry into the back of the switchgear and may not be able to get to 6 time the trade size. Is this exception just for use in determining the depth of the box for this type pull or is it intended for the proper wire bending radius?

 

[augie47]

I believe the answer in your situation is that the removable cover has no bearing on the conduits entering from the bottom or the distance between conduits. You might aslo need to note that since you mentioned conduitS, 314.28(A)(2) also requires you to add to the 6 x measuremnt, the sum of diameters of other conduits entering in the same wall ad same row.

 

[charlie b]

Code states that the distance between raceways for angle pulls needs to be 6 times the trade size of the conduit. Although the exception states that if a raceway enters in a wall of the box where there is a removable cover then the distance from the entry to the cover can be determined by using table 312.6A.

I think you are confusing two separate articles that deal with separate issues. First of all, I know of no code article that restricts the distance between raceways. Secondly, the article that talks about 6 times the trade size and removable covers, 314.28, is talking about the minimum size of the box itself. Third, 312.6 is talking about bending space within a box. If you are running conduits through the box, then you are not using the internals of the box as "space to move cables around in." So 312.6 would not apply to your installation.

 

[RUWired]

My question is does the exception alow you to not have to use the 6 times the trade size of the conduit between raceways.

The distance "between" conduits inside the box must meet the 6x. The depth of the box is based off table 312.6(A).

The paragraph after 314.28(A)2 exception explains the requirement.

"The distance between raceway entries enclosing the same conductor shall not be less than six times the metric designator (trade size) of the larger raceway".

If you have a 4" raceway with 600 kcmil wire. You will need a box or wire way atleast 29" long and 8" in depth.( 24" between raceways + 4-1/2" for the raceway and 1/2" for the locknut and bushing.
Rick

 

[e57]

Good question - and for some reason - (stop the presses) I can not fabricate an answer..... 'Cause I think I am wondering the same that you are.

But will say - it only applies if the conductors are #4 or larger....

Anyway - Not sure Charlie is reading the same code 314.28 - as it does seem to contradict a little of what he was saying.

First of all, I know of no code article that restricts the distance between raceways.

2) Angle or U Pulls. Where splices or where angle or U pulls are made, the distance between each raceway entry inside the box and the opposite wall of the box shall not be less than six times the metric designator (trade size) of the largest raceway in a row. This distance shall be increased for additional entries by the amount of the sum of the diameters of all other raceway entries in the same row on the same wall of the box. Each row shall be calculated individually, and the single row that provides the maximum distance shall be used.

Exception: Where a raceway or cable entry is in the wall of a box or conduit body opposite a removable cover, the distance from that wall to the cover shall be permitted to comply with the distance required for one wire per terminal in Table 312.6(A).

The distance between raceway entries enclosing the same conductor shall not be less than six times the metric designator (trade size) of the larger raceway.

When transposing cable size into raceway size in 314.28(A)(1) and (A)(2), the minimum metric designator (trade size) raceway required for the number and size of conductors in the cable shall be used.

And that exception does seem a little mis-leading.

 

[charlie b]

Anyway - Not sure Charlie is reading the same code 314.28 - as it does seem to contradict a little of what he was saying.

I am reading the same article, and it does no such thing.

Read again the text you highlighted in red. It is talking about conduit entries and it is talking about enclosing the same conductor. This has nothing to do with the distance between any two conduits.

Simple example: There are two conduits, numbered 1 and 2, that connect to the North face of a pull box. There are two more conduits, numbered 3 and 4, that connect to the South face of the same pull box. There is a set of conductors that enter the box via in conduit 1, and that leave the box via conduit 3. There is another set of conductors that enter the box via conduit 2, and that leave the box via conduit 4. Thus, conduits 1 and 3 enclose the same conductors. 314.28 (and in particular the red text from your post) is telling us that there is a minimum distance from the entry point of conduit 1 to the entry (or exit, if your prefer) point of conduit 3. It is not telling us that there is a minimum separation between conduits 1 and 2. We know that because conduits 1 and 2 do not enclose the same conductor.

 

[RUWired]

I believe the OP is asking the distance between raceways like a LB would be.In the bottom and out the back. Not as in parallel runs.

 

[e57]

Read again the text you highlighted in red.~ This has nothing to do with the distance between any two conduits.

Simple example: ~ Thus, conduits 1 and 3 enclose the same conductors. 314.28 (and in particular the red text from your post) is telling us that there is a minimum distance from the entry point of conduit 1 to the entry (or exit, if your prefer) point of conduit 3.~

Seems to have something to do with the distance between these two - don't it?

 

[charlie b]

Seems to have something to do with the distance between these two - don't it?

I don't quite understand your point, or your question. Between these two what? What I am saying is that the code is talking about the distance between two opposite walls, not between two conduits entering the same wall. Are you seeing it differently?

 

[jrannis]

The distance "between" conduits inside the box must meet the 6x. The depth of the box is based off table 312.6(A).

The paragraph after 314.28(A)2 exception explains the requirement.

"The distance between raceway entries enclosing the same conductor shall not be less than six times the metric designator (trade size) of the larger raceway".

If you have a 4" raceway with 600 kcmil wire. You will need a box or wire way atleast 29" long and 8" in depth.( 24" between raceways + 4-1/2" for the raceway and 1/2" for the locknut and bushing.
Rick

I can't say I agree.
If the trade size of the conduit is 4" then 6x4 is 24" to the opposite wall.
If the conduit leaves out of the back of the box opposite of the removable cover then a 6"x24" "junction box" 6 inches deep would work.

 

[RUWired]

If the trade size of the conduit is 4" then 6x4 is 24" to the opposite wall.

The paragraph after the exception quotes between raceways.

The distance "between raceway" entries enclosing the same conductor shall not be less than six times the metric designator (trade size) of the larger raceway.

If the conduit leaves out of the back of the box opposite of the removable cover then a 6"x24" "junction box" 6 inches deep would work.

The exception refers us to table 312.6(A) and for the 1 wire per terminal, 600 kcmil = 8".

Exception: Where a raceway or cable entry is in the wall of a box or conduit body opposite a removable cover, the distance from that wall to the cover shall be permitted to comply with the distance required for one wire per terminal in Table 312.6(A).

 

[wwhitney]

Simple example: There are two conduits, numbered 1 and 2, that connect to the North face of a pull box. There are two more conduits, numbered 3 and 4, that connect to the South face of the same pull box. There is a set of conductors that enter the box via in conduit 1, and that leave the box via conduit 3. There is another set of conductors that enter the box via conduit 2, and that leave the box via conduit 4. Thus, conduits 1 and 3 enclose the same conductors. 314.28 (and in particular the red text from your post) is telling us that there is a minimum distance from the entry point of conduit 1 to the entry (or exit, if your prefer) point of conduit 3. It is not telling us that there is a minimum separation between conduits 1 and 2. We know that because conduits 1 and 2 do not enclose the same conductor.

I'm new at this, but a couple of comments about this example:

1) In this example, if conduit 1 is directly opposite conduit 3 (and conduit 2 opposite conduit 4), would one have the option of not using this box as a pull box, so that 314.28 wouldn't apply at all?

2) If you do use this as a pull box, then wouldn't 314.28(1) "Straight Pulls" apply, requiring the length of the box to be eight times the trade size of the largest raceway?

Back to 314.28(2), the second paragraph states "The distance between raceway entries enclosing the same conductor shall not be less than six times the trade size of the larger raceway". This requirement seems to be very general--for a conductor entering via conduit on the side and exiting via conduit on the back, it would apply to the distance separating the side entry and the rear entry (exit).

To what point of the rear entry should the distance be measured? If the distance is measured to the closest point of the conduit, then the practical effect would be to increase the minimum distance between the side entry and the opposite wall to six times the larger trade size plus the actual diameter of the rear entry.

Yours, Wayne

 

[finhead]

Exhibit 314.11 (page 353) in the 2008 NEC Handbook illustrates the question about raceways enclosing the same conductor.