Fixture Whips

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ActionDave said:
Fascinating. This is an area of the code I have glossed over forever. I'm both intrigued and annoyed. Someone is going to have to explain to me what is functionally different about TFFN and THHN that I can run 100 feet of 16AWG on a 20A breaker and I can't even run one foot of 14AWG.
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So now I am confused. I thought the small fixture whip 16AWG size was limited to 6 feet. It is not length limited? What section is this?

I will happily admit that on jobs that are not getting inspected, if I need a troffer/LED panel whip longer than 6 feet, I make one out of 14AWG MC on a 20 amp circuit. Oh my, the horror.
 
240.5. It's that wacky tap rule I mentioned in reference to your other post in this thread.

(2) Fixture Wire​


Fixture wire shall be permitted to be tapped to the branch-circuit conductor of a branch circuit in accordance with the following:
  1. 15- or 20-ampere circuits — 18 AWG, up to 15 m (50 ft) of run length
  2. 15- or 20-ampere circuits — 16 AWG, up to 30 m (100 ft) of run length
  3. 20-ampere circuits — 14 AWG and larger
  4. 30-ampere circuits — 14 AWG and larger
  5. 40-ampere circuits — 12 AWG and larger
  6. 50-ampere circuits — 12 AWG and larger


​

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electrofelon said:
So there is no 6 ft length limitation for your typical troffer whip (if using fixture wire)? Could have sworn that 6 ft thing was a thing, is there something else at play?
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ActionDave said:
Unsupported lengths of flex six feet or less are allowed. If you want to go a hundred feet you're gonna have to spring for some straps.
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Read 348.20 and 410.17 C carefully
Lot going on in in both those statements.
One discussion is conductor length and one is raceway type length.
When you combine both statements one could be lead astray.
Then go read 330.30 and be sure to read the last sentence after 330.30 (D) 3

Most are correct however do not get mislead as a whole. Each can be done after applying certain rules.

After review of above head on over to 402. Read slowly as you get to 402.5 - 402.12. stop and think after 402.7.
Then after 402.12 head on over to 240.5.
Then it should clear thing up a little.

I base this on 2017 code for previous OP saying he is on 2017 NEC

For fun have. A look at 310.10.
I would say type TFN and TFFN are dry location only no damp.
A lot of lay in fixtures are damp location listed. See 402.2
IFN sends you to 410.52 and then back agai


Lot going on in a simple question.
Each type of install requires different methods to meet NEC.
Rick 0920 said:
A lot of contractors today "daisy chain" their troffer fixtures. If you do this, you can't use the factory pre-made fixture whips unless the conductors have an ampacity of 20 amps. For example, if you daisy chained 30 troffers together, the whip between fixture #1 and #2 will see the load of the other 29 fixtures. I used to do this often because if your whips are 6' or less, Art. 330.30 (D)(2) allow you to run the whips unsupported which will save you lot of work not having to install your own ceiling wires.
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So I have a Question
TFN and TFFN is dry location only?
I see it as a yes. Some lay in fixtures are damp location listed as well as other luminaries. So the application of a whip and or whip type should be chosen wisely.

Back to 348 and the use of a THHN/THWN conductor. This would require a branch circuit size if used in a damp location. Another item is it is allowed to be concealed. It would also be allowed to installed unsupported and secured if 6' or less. For this discussion 348.30 exception 4 accessable ceiling.

Just some thought on the issue.
 
Tulsa Electrician said:
Read 348.20 and 410.17 C carefully
Lot going on in in both those statements.
One discussion is conductor length and one is raceway type length.
When you combine both statements one could be lead astray.
Then go read 330.30 and be sure to read the last sentence after 330.30 (D) 3

Most are correct however do not get mislead as a whole. Each can be done after applying certain rules.

After review of above head on over to 402. Read slowly as you get to 402.5 - 402.12. stop and think after 402.7.
Then after 402.12 head on over to 240.5.
Then it should clear thing up a little.

I base this on 2017 code for previous OP saying he is on 2017 NEC

For fun have. A look at 310.10.
I would say type TFN and TFFN are dry location only no damp.
A lot of lay in fixtures are damp location listed. See 402.2
IFN sends you to 410.52 and then back agai


Lot going on in a simple question.
Each type of install requires different methods to meet NEC.
Click to expand...
I'm not doing all that. Six feet of flex going down to a light can be unsupported.
 
The 6' fixture whip limit is only for 3/8" FMC.

348.20(A) Minimum.
FMC less than metric designator 16 (trade size 1∕ 2) shall not be used unless permitted in 348.20(A)(1) through (A)(5) for metric designator 12 (trade size 3∕ 8).
(1) For enclosing the leads of motors as permitted in 430.245(B)
(2) In lengths not in excess of 1.8 m (6 ft) for any of the following uses:
a. For utilization equipment
b. As part of a listed assembly
c. For tap connections to luminaires as permitted in 410.117(C)
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Tulsa Electrician said:
Read 348.20 and 410.17 C carefully
Lot going on in in both those statements.
One discussion is conductor length and one is raceway type length.
When you combine both statements one could be lead astray.
Then go read 330.30 and be sure to read the last sentence after 330.30 (D) 3

Most are correct however do not get mislead as a whole. Each can be done after applying certain rules.

After review of above head on over to 402. Read slowly as you get to 402.5 - 402.12. stop and think after 402.7.
Then after 402.12 head on over to 240.5.
Then it should clear thing up a little.

I base this on 2017 code for previous OP saying he is on 2017 NEC

For fun have. A look at 310.10.
I would say type TFN and TFFN are dry location only no damp.
A lot of lay in fixtures are damp location listed. See 402.2
IFN sends you to 410.52 and then back agai


Lot going on in a simple question.
Each type of install requires different methods to meet NEC.

So I have a Question
TFN and TFFN is dry location only?
I see it as a yes. Some lay in fixtures are damp location listed as well as other luminaries. So the application of a whip and or whip type should be chosen wisely.

Back to 348 and the use of a THHN/THWN conductor. This would require a branch circuit size if used in a damp location. Another item is it is allowed to be concealed. It would also be allowed to installed unsupported and secured if 6' or less. For this discussion 348.30 exception 4 accessable ceiling.

Just some thought on the issue.
Click to expand...
Most of what we call THHN today is actually THHN/THWN-2 if you took a magnifying glass and read the printing on the insulation. This is what allows us to use it in PVC conduits underground and conduits on the outside of buildings since the interior of such conduits are considered a wet location.
 
Rick 0920 said:
Most of what we call THHN today is actually THHN/THWN-2 if you took a magnifying glass and read the printing on the insulation. This is what allows us to use it in PVC conduits underground and conduits on the outside of buildings since the interior of such conduits are considered a wet location.
Click to expand...
But THHN/THWN-2 are not fixture wires. The fixture wires are the types shown in Table 402.3. They are all for dry locations only.
 
Two important Sections in regard to fixture wire:
402.10 Uses Permitted. Fixture wires shall be permitted (1) for installation in luminaires and in similar equipment where enclosed or protected and not subject to bending or twisting in use, or (2) for connecting luminaires to the branchcircuit conductors supplying the luminaires.
402.12 Uses Not Permitted. Fixture wires shall not be used as branch-circuit conductors except as permitted elsewhere in this Code
 
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