Type UF cable / Table 5, Chapter 9

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klmiller1981

Member
Location
Lake Jackson, Texas
Good Morning, and thanks for the opportunity to inquire on this forum.

I have a question concerning Table 5 of Chapter 9. I don't see Type UF cable listed in this table, for the purpose of selecting a proper size conduit for such a cable.

Is there a reason UF cable is not listed in Table 5? Is the reason because UF is listed for direct burial? Is this the correct table to reference concerning dimensional properties of conductors for purpose of determining conduit fill?

Any help or reference material is very much appreciated.

Apologies in advance if I posted this in the wrong section.

Thanks!
 
tkb

tkb

Senior Member
Location
MA
Table 5 is for conductors and not cable assemblies..
UF is a cable. See Chapter 9 Note 9.
You will need to use the widest diameter for the conduit fill. If it is a single cable you can use 53% fill.
 
augie47

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
tkb said:
Table 5 is for conductors and not cable assemblies..
UF is a cable. See Chapter 9 Note 9.
You will need to use the widest diameter for the conduit fill. If it is a single cable you can use 53% fill.
Click to expand...

anybody ever have an inspector question/calculate/enforce that ????
 
kwired

kwired

Electron manager
Location
NE Nebraska
tkb said:
Table 5 is for conductors and not cable assemblies..
UF is a cable. See Chapter 9 Note 9.
You will need to use the widest diameter for the conduit fill. If it is a single cable you can use 53% fill.
Click to expand...

augie47 said:
anybody ever have an inspector question/calculate/enforce that ????
Click to expand...
No, but IMO if the cables are in a sleeve for physical protection no fill requirements apply, if you are pulling the cable through a complete raceway system (which is pointless IMO unless in some pinch and you have no THHN/THWN or other suitable conductors available to pull) then you must meet fill requirements.
 
K

klmiller1981

Member
Location
Lake Jackson, Texas
MasterTheNEC said:
Well...since you are in Texas......if it happens to be Encore Wire's Type UF....let me know..;)
Click to expand...

Planning to use Southwire UF-B #8/3 w/#10G (which is what is most readily available in my area).

Currently there is a 2" PVC conduit that runs underground from the main panel to the garage which contains a 12/2 NM cable that goes to a 2-gang electrical box and splits into three branches (powering various lights and receptacles in the garage and adjacent living room. The circuit is protected by single pole 20 amp breaker. The conduit is roughly 12" below grade which is too shallow and crosses paths with a 3/4" conduit feeding the A/C compressor. This causes the 2" conduit to make over 360 degrees in bends (another violation), not to mention the wrong cable type for an underground installation.

In the process of installing a fence, I find that one of the post settings will interfere with the 2" conduit as it sits now. As there are numerous code violations associated with the current installation, I find this the perfect opportunity for the following:

  • Demo existing 2" conduit, 12/2 cable, 20 amp breaker, 2-gang electrical box, and 3/4" A/C conduit
  • Install new conduit from the panel to a type FSCC or similar electrical box (1 in, 2 out)
  • From the two "out" ports of the FSCC box, switch the A/C conduit and garage conduit, eliminating the over 360 degree bend violation to the garage
  • Route a new conduit to the garage away from post settings and at a depth of 18"
  • Pull a new feeder to the A/C compressor and pull the #8/3 UF-B cable to the garage.
  • Install a 70 amp indoor panel in the garage in place of the 2-gang box.
  • Place the three existing branches in the garage onto three separate 15 amp breakers in the 70 amp panel.
  • Replace the existing single pole 20 amp breaker with a 2 pole 40 amp ground fault circuit breaker to power the 70 amp panel via the #8/3 UF-B cable.

I believe this will eliminate any code violations, and allow the final fence post to be set. I see from the Southwire catalog that my desired cable has a dimension of 1.053" X 0.319" inches. Where I'm finding confusion is in Table 1 of Chapter 9. The table specifies a percentage of cross-sectional area per number of conductors AND/OR cables. What I am installing is a single cable with multiple conductors. Am I to assume that the "AND/OR" wording is meant to be understood as which ever carries the worst case? As the cable contains three conductors it may only occupy 40%, correct??

Thank you all for the input and any advice or recommendations.
 
MasterTheNEC

MasterTheNEC

CEO and President of Electrical Code Academy, Inc.
Location
McKinney, Texas
Occupation
CEO
klmiller1981 said:
I see from the Southwire catalog that my desired cable has a dimension of 1.053" X 0.319" inches. Where I'm finding confusion is in Table 1 of Chapter 9. The table specifies a percentage of cross-sectional area per number of conductors AND/OR cables. What I am installing is a single cable with multiple conductors. Am I to assume that the "AND/OR" wording is meant to be understood as which ever carries the worst case? As the cable contains three conductors it may only occupy 40%, correct??

Thank you all for the input and any advice or recommendations.
Click to expand...

Follow Note 9 and treat it as a single conductor in terms of the fill requirements of Table 1. If the cable is elliptical then follow the directions with the information SW has provided in Note 9. Otherwise use the actual diameter as defined in Note 5 but the cross-sectional area of 1 cable ( 53%) is to be used. Also keeping in mind that Table 1 applies to complete runs of conduit or tubing and not the portions used for issue of physical protection. So if you install the UF-B in a raceway to facilitate the protection of it (since it can be direct buried) then the fill requirements are not needed as it is not a complete run as stated in Note 2.
 
kwired

kwired

Electron manager
Location
NE Nebraska
klmiller1981 said:
Planning to use Southwire UF-B #8/3 w/#10G (which is what is most readily available in my area).

Currently there is a 2" PVC conduit that runs underground from the main panel to the garage which contains a 12/2 NM cable that goes to a 2-gang electrical box and splits into three branches (powering various lights and receptacles in the garage and adjacent living room. The circuit is protected by single pole 20 amp breaker. The conduit is roughly 12" below grade which is too shallow and crosses paths with a 3/4" conduit feeding the A/C compressor. This causes the 2" conduit to make over 360 degrees in bends (another violation), not to mention the wrong cable type for an underground installation.

In the process of installing a fence, I find that one of the post settings will interfere with the 2" conduit as it sits now. As there are numerous code violations associated with the current installation, I find this the perfect opportunity for the following:

  • Demo existing 2" conduit, 12/2 cable, 20 amp breaker, 2-gang electrical box, and 3/4" A/C conduit
  • Install new conduit from the panel to a type FSCC or similar electrical box (1 in, 2 out)
  • From the two "out" ports of the FSCC box, switch the A/C conduit and garage conduit, eliminating the over 360 degree bend violation to the garage
  • Route a new conduit to the garage away from post settings and at a depth of 18"
  • Pull a new feeder to the A/C compressor and pull the #8/3 UF-B cable to the garage.
  • Install a 70 amp indoor panel in the garage in place of the 2-gang box.
  • Place the three existing branches in the garage onto three separate 15 amp breakers in the 70 amp panel.
  • Replace the existing single pole 20 amp breaker with a 2 pole 40 amp ground fault circuit breaker to power the 70 amp panel via the #8/3 UF-B cable.

I believe this will eliminate any code violations, and allow the final fence post to be set. I see from the Southwire catalog that my desired cable has a dimension of 1.053" X 0.319" inches. Where I'm finding confusion is in Table 1 of Chapter 9. The table specifies a percentage of cross-sectional area per number of conductors AND/OR cables. What I am installing is a single cable with multiple conductors. Am I to assume that the "AND/OR" wording is meant to be understood as which ever carries the worst case? As the cable contains three conductors it may only occupy 40%, correct??

Thank you all for the input and any advice or recommendations.
Click to expand...
If you are installing raceway why do you want to pull a cable assembly through it? Pulling THWN through it should cost less then UF cable, will require smaller minimum raceway size and will pull easier.

GFCI on the feeder means if you have a fault you lose the entire garage instead of just one circuit or even just a part of a circuit if using GFCI receptacles, that may not be desired, then again if you have a refrigerator or freezer it may be noticed even sooner that it has lost power then if it is isolated on it's own GFCI. But if this is a garage where someone does hobby stuff at night - a fault in a tool or something takes the lights out with it. Use your own discretion on selecting the GFCI location I guess.
 
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