Fix. Tail

[Alwayslearningelec]

Is a fixture tail considered a tap? What' determines what wires size the tail can be per code?..............

 

[don_resqcapt19]

It is not a tap, but "undersized" conductors are permitted between the branch circuit conductors and the fixture. See 240.5(B)(2) and make sure you note that this only applies to "fixture" wire of the types found in Table 402.3.

 

[Tulsa Electrician]

I would also recommend reviewing. 2014 NEC
250.122 (E) Play close attention to what it says related to sizing
402.5
402.6
402.10
402.11
As far as the word "tap" goes, the word "tapped" is used in 240.5 (B) (2)
Also in order for for the Fixture Wire ( Whip/Tail ) to be code compliant using a reduced conductor size for a given Over current device.
240.4(E) (2) is used
This is what takes you to 240.5 (B) (2) and so on.

 

[Jpflex]

It is not a tap, but "undersized" conductors are permitted between the branch circuit conductors and the fixture. See 240.5(B)(2) and make sure you note that this only applies to "fixture" wire of the types found in Table 402.3.

How about 12 awg thhn 20 amp circuit going to 4 square metal box then connecting (tapping) here onto 14 awg white romex to 4-0 plastic nail on box for lighting low 1.9 wat LED lamp? Would this be legal or considered a tap connection?

 

[augie47]

How about 12 awg thhn 20 amp circuit going to 4 square metal box then connecting (tapping) here onto 14 awg white romex to 4-0 plastic nail on box for lighting low 1.9 wat LED lamp? Would this be legal No or considered a tap connection? No

 

[Jpflex]

So even though the single light Only uses a fraction of an amp and parallels power in box I would need to run same 12 Awg to light as rest of branch circuit conductors?

 

[augie47]

yes

 

[don_resqcapt19]

How about 12 awg thhn 20 amp circuit going to 4 square metal box then connecting (tapping) here onto 14 awg white romex to 4-0 plastic nail on box for lighting low 1.9 wat LED lamp? Would this be legal or considered a tap connection?

That would not be code compliant unless you have OCPD at 15 amps of less for the 14 AWG NM.
However if you would use FMC and one of the conductors of the type shown in 402.3, you could use 18AWG for that installation and comply with the code.

 

[augie47]

Before jumping into using a fixture wire, however, be sure to note:

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.

 

[Jpflex]

Before jumping into using a fixture wire, however, be sure to note:

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.

I think the code doesn’t make much sense here as 14 NM has larger ampacity and protection than 16 - 18 AWG fixture wire but it’s code so I guess we’ll comply

 

[Jpflex]

That would not be code compliant unless you have OCPD at 15 amps of less for the 14 AWG NM.
However if you would use FMC and one of the conductors of the type shown in 402.3, you could use 18AWG for that installation and comply with the code.

Yes interesting. I did look at the code and those codes referenced within this code. However, it still reads that the fixture conductor must be protected at its ampacity.

Clearly the fixture wire ampacity is lower than the upstream 12 awg branch circuit.

For this reason I believe the code says to use supplementary overcurrent protection (for fixture wires) which can not replace main over current device.

How exactly do you install supplementary overcurrent protections downstream of main ocd breaker? Thanks never saw this done

 

[augie47]

Yes interesting. I did look at the code and those codes referenced within this code. However, it still reads that the fixture conductor must be protected at its ampacity.

Clearly the fixture wire ampacity is lower than the upstream 12 awg branch circuit.

For this reason I believe the code says to use supplementary overcurrent protection (for fixture wires) which can not replace main over current device.

How exactly do you install supplementary overcurrent protections downstream of main ocd breaker? Thanks never saw this done

Your statement is incorrect. You need to read 240.5 again especially 240.5(B) and (B)(2)

 

[ramsy]

It is not a tap, but "undersized" conductors are permitted between the branch circuit conductors and the fixture. See 240.5(B)(2) and make sure you note that this only applies to "fixture" wire of the types found in Table 402.3.

Luminaire may also require 90C rated branch conductors, per 410.68

 

[Sparky27577]

Is a fixture tail considered a tap? What' determines what wires size the tail can be per code?..............

That's a common sense question. Unless the whip was factory installed and the light hasn't been modified in the field the wire is always gonna be smaller and sized according to the load of the device. Since none of us who actually do the work are authorized to put a ul sticker on our work. So just because a device is not passing a load through it and we know by common sense it will only draw the single amp or so of power it demands. We have to size wire according to the old, or rather vice versa. You can use bigger wire but never smaller.

 

[Fred B]

Not to confuse site wiring with the fixture wiring. Usually the fixture wiring is part of the listed product and tested to meet a certain criteria. Building wire installation must meet the NEC requirements. This in part allows the fixture wire to be in some cases much smaller than the building's wiring.
In the case particularly related to LED, the draw is so miniscule that even the 18ga or 22ga fixture wire is "oversized" by the potential continuous draw of the fixture.
Or another POV, what size wire is needed to carry 0.5 or 0.8 amp of a single light bulb? That is how the wire of the fixture is sized. Also the mfg may limit the bulb size allowed because of the fixture wiring used in the manufacturing allowing for a smaller fixture wire.

 

[infinity]

A fixture tail is not required to be factory made or installed. As Don mentioned in post #8 a field made and installed tail of FMC and fixture wire would comply when using reduced size fixture wire conductors.

Going back to the OP the tail conductors would have to be suitable for the load and can be sized according to Table 402.5 and 240.5(B)(2).

 

[Fred B]

A fixture tail is not required to be factory made or installed. As Don mentioned in post #8 a field made and installed tail of FMC and fixture wire would comply when using reduced size fixture wire conductors.

Going back to the OP the tail conductors would have to be suitable for the load and can be sized according to Table 402.5 and 240.5(B)(2).

Always viewed the fixture tail as the wiring provided via the factory wiring for connection between the mfg fixture and the building wiring of an individual light fixture. Typical residential wall or ceiling lights.
Are you now speaking of or referring to a whip, typically installed on a trougher?
Never considered downsizing from the branch wire but suppose if criteria of no other extension possible, then the ampacity of the individual fixture could be considered in size of whip for the individual fixture per your reference. But if the wiring of that whip/fixture combo could be extended to unlimited (mechanically) additional fixtures it would fail to meet the ability to use a downsized conductor compared to the branch wire.

 

[infinity]

Are you now speaking of or referring to a whip, typically installed on a trougher?

Yes a lay-in style troffer fixture or a recessed high hat style fixture. When the wiring method is EMT above a suspended ceiling fixtures are typically feed by a fixture tail (or whip) with #18 fixture wires.

 

[Fred B]

Yes a lay-in style troffer fixture or a recessed high hat style fixture. When the wiring method is EMT above a suspended ceiling fixtures are typically feed by a fixture tail (or whip) with #18 fixture wires.

Never heard it called a tail.

 

[infinity]

Never heard it called a tail.

That's what it's called around here. Outside of this forum I never hear it being called fixture whip.