Wiring suspended fixtures

[Radix2]

Talking about LED and fluorescent fixtures not supplied with a cord. I did a search and surprisingly could not find much detail on specifics - everything from "add a cord" to romex with cable clamps.

what code compliant options do we have for wiring these ?


To make this useful thread I will try to pose some generalized questions for people with different preferences.

1. can plug cords be added to these standard fixtures - if so what markings/specs are required?

2. when hard wired - what wiring cables or conduits are acceptable or required - assume a cable hung fixture with a knockout and a ceiling box at the other end. NM, MC, BX, AC, plastic conduits, etc ?

2.b if passing through a ceiling ? Metal ceiling?

3. flexible (stranded) wire required ? Assume cable/chain hung fixture

4. any requirements on the low voltage control wire drop.

 

[pattenp]

Use a ceiling box with a cover plate that has a knockout. Use SO cord with strain relief connectors on both ends.

 

[Radix2]

I'm thinking the easiest box to use in the metal ceiling is an old work round ceiling box that I can use a hole saw to cut out. Cover with plate w/knock out.

Was originally thinking about using some sort of armored conduit and putting the dimming inside...if using SOOJ...

Dimming wire.. through strain reliefs w/SO ?

grommeted hole drilled through knock out cover ? Run outside of box ?

 

[tyme2par4]

If there is a seperate LV control wire, I would go with flexible conduit, and THHN wire from the J box to the fixture. That way both power and control wires are taken care of in 1 step.

 

[Brandon314159]

I was going down this route as well. I have 6 fixtures with KO holes and wires.

I have a very large roll of 14/3 SO cord and I was thinking that, plus the reliefs on both ends, so I can move the light around a bit if I change shop configuration (and also bring two light SO cords to one box...save running a bunch of extra MC).

Not sure how to get the low voltage 0-10V dimmer circuit out though. I suppose a separate hole+strain for the cable I have.

 

[Radix2]

If there is a seperate LV control wire, I would go with flexible conduit, and THHN wire from the J box to the fixture. That way both power and control wires are taken care of in 1 step.

I am trying to get input here on all the code compatible methods for these fixtures - anyone know if both stranded and solid THHN are acceptable ?

Or NM wire in conduit.

I don't expect that many of us expect these to move - but since it is a flexible mount is stranded/flexible wires code required?

(I see that the MC luminary cable with the dimming lines inside is mostly solid conductors...maybe a troffer vs suspended option) http://www.afcweb.com/mc-metal-clad-cables/mc-luminary-type-mc-pcs/mc-luminary/

 

[sberry]

Put a square box so fixtures fit and use plug and recept. The strain connectors are great if you are putting strain on them but you shouldn't be pulling on a cord here anyway, not sure its listed but use a common cable connector if I have to.
That isn't really a strain connector anyway but a cord to box connector, nice to keep water out.

 

[sberry]

I do violate this a bit at my own risk and say it was there back in the day but if the outlets are up in the ceiling and not accessible I skip out on gfci. Its so much easier to plug to service or move or even change with a 3 way adapter or power strip. I managed to re wire a whole bay the other day without really wiring.

 

[alfredeneuman]

Use a ceiling box with a cover plate that has a knockout. Use SO cord with strain relief connectors on both ends.

Any cord connecting fixtures must be equipped with a plug on 1 end and plugged into a receptacle or a connector body.

NEC 400.7(B)

The receptacle or connector body is supposed to be directly above the fixture, so by Code only minor relocations can be made.

 

[Radix2]

Is this an accurate summation of the more specific code for this item -? I dont think 400.7 is the right spot since there is a specific code for luminaires and that one refers to more general devices ?

Connection of Electric-Discharge and LED Luminaires
The 2011 Code changed the requirements for boxes and wiring methods for electric-discharge luminaires, to include LED luminaires.

Electric-discharge and LED luminaires supported independently of the outlet box must be connected to the branch circuit with a raceway, or with Types MC, AC, or NM cable [410.24(A)].
When an electric-discharge luminaire or LED luminaire is surface mounted over a concealed outlet box, and not supported by the outlet box, the luminaire must be provided with suitable openings that permit access to the branch-circuit wiring within the outlet box [410.24(B)].
Electric-discharge luminaires can be cord-connected if the cord is visible for its entire length and is plugged into a receptacle, and the installation complies with 410.62(C).

This makes it sound as if bare NM cable could be dropped to the fixture...true?


this version lists flexible cable...hmm .62 b&c

410.24 Connection of Electric-Discharge Luminaire.
(A) Independent of the Outlet Box. Electric-discharge luminaires supported independently of the outlet box shall be connected to the branch circuit through metal raceway, nonmetallic raceway, Type MC cable, Type AC cable, Type MI cable, nonmetallic sheathed cable, or by flexible cord as permitted in 410.62(B) or 410.62(C).

I think this is 410.62c

A luminaire can be cord-connected if:

The luminaire is mounted directly below the outlet box, and
The flexible cord:

Is visible for its entire length,
Isn’t subject to strain or physical damage [400.10], and
Terminates in an attachment plug, canopy with strain relief, or manufactured wiring system connector complying with 604.6(C).

So the argument would be that a jbox cover w/strain relief is accepted as a "canopy with strain relief"

Judging by my reading, inspectors are all over the map on this one.

 

[pattenp]

Any cord connecting fixtures must be equipped with a plug on 1 end and plugged into a receptacle or a connector body.

NEC 400.7(B)

The receptacle or connector body is supposed to be directly above the fixture, so by Code only minor relocations can be made.

You are misreading the code. 400.7(B) applies to 400.7(A)(3),(6)&(8). 400.7(A)(2) allows flexible cords to attach luminaries and is not covered by 400.7(B) requiring a plug. What I suggested is correct.

 

[larry_g]

I used a premade whip cable from the home depot for a couple of mine.. Search out "bx whip"

lg
no neat sig line

 

[pattenp]

Is this an accurate summation of the more specific code for this item -? I dont think 400.7 is the right spot since there is a specific code for luminaires and that one refers to more general devices ?

This makes it sound as if bare NM cable could be dropped to the fixture...true?

this version lists flexible cable...hmm .62 b&c

I think this is 410.62c

So the argument would be that a jbox cover w/strain relief is accepted as a "canopy with strain relief"

Judging by my reading, inspectors are all over the map on this one.

There's enough "or's" in that section to power a ship. I see plenty of hanging strip light fixtures installed today with flex cord and no plug.

 

[Radix2]

There's enough "or's" in that section to power a ship. I see plenty of hanging strip light fixtures installed today with flex cord and no plug.

Absolutely - I thought it might be simple and someone could quote the code, but in further research, it is all over the place. Some want only armored cable and stranded wires to god knows what.

Not to mention that a knotted piece of zip cord run through a ragged chain loop hole is what is typically provided on a UL listed pendant canopy...

Thought it would be good to have a thread that laid out what is code since I couldn't find one.

 

[Barnabas]

What does your local code say?