Jumps between light fixtures.

[darekelec]

Does anybody know the section or explanation that I am not allowed to make 'jumps' with AC cable between rows of for example fluorescent lights or recess lights in commercial applications?
Same for emt interconnecting light fixtures.
In my neck of woods one has to make home runs to a junction box for each row or lay in light fixture.
A double BX connector and splice inside light fixture seems fine for me.
THX

 

[iwire]

There is no NEC rule prohibiting what you want to do.

There may be a local amendment but more likely it is just tradition.

 

[darekelec]

I knew it. I knew it.
Let's not forget about the 6 ft rule of flex but that's not the case here.
I guess that is a tradition around here.

 

[darekelec]

Is it possible that my local tradition is based on local interpretation of 250.148

(B) Grounding Continuity. The arrangement of grounding connections shall be such that the disconnection or the removal of a receptacle, luminaire, or other device fed from the box does not interfere with or interrupt the grounding continuity.

By removing 1 light fixture I would interrupt the grounding continuity?

 

[jusme123]

Is it possible that my local tradition is based on local interpretation of 250.148

(B) Grounding Continuity. The arrangement of grounding connections shall be such that the disconnection or the removal of a receptacle, luminaire, or other device fed from the box does not interfere with or interrupt the grounding continuity.

By removing 1 light fixture I would interrupt the grounding continuity?

...if you know and quote the reason, why bother asking the question, seems pretty strait forward to me?

 

[curt swartz]

...if you know and quote the reason, why bother asking the question, seems pretty strait forward to me?

The OP is not asking about fixtures mounted to a box. You are suggesting it is against code to loop from fixture to fixture? When installing rows of fluorescent strips in a warehouse each fixture must have a separate fixture whip? How about standard recessed lights in a dwelling? Each fixture must have a separate cable from the switch?

 

[GoldDigger]

The OP is not asking about fixtures mounted to a box. You are suggesting it is against code to loop from fixture to fixture? When installing rows of fluorescent strips in a warehouse each fixture must have a separate fixture whip? How about standard recessed lights in a dwelling? Each fixture must have a separate cable from the switch?

In residential wiring, this is the reason that a device in a box must get its ground connection from a pigtail rather than via direct connection of two ground wires to a common screw on the device.
The case of a luminaire such as you describe is more difficult to accommodate in that you would be removing not just a connected device but a section of the raceway.
In the case of luminaires, that would seem to mean that a ground wire must go from one device to the second one downstream, bypassing the intermediate luminaire, in a leap-frog fashion.
One way of doing this would be to run a conduit the length of the run and, as you suggest, connect each fixture whip to that conduit for grounding rather than relying on the luminaire itself or a ground wire which runs inside the luminaire.

But the context of 250.148, wiring within a box, ("fed from the box") seems to keep it from applying to this situation. When you completely remove one luminaire, you are also removing the power feed to downstream luminaires, so the ground continuity would seem to be moot.

 

[iwire]

...if you know and quote the reason, why bother asking the question, seems pretty strait forward to me?

That section does not apply to a fixture with a self contained wiring compartment.

 

[roger]

Let's not forget about the 6 ft rule of flex but that's not the case here.

What 6 ft rule are you refering too?

Roger

 

[Little Bill]

Don't have time to look it up now, but there is a rule/code saying unless a fixture is listed for use as a raceway, you can't feed from one to the other. Something similar to this anyway.

However, most strips lights (fluorescent) that I see are fed through or daisy chained.

 

[iwire]

Don't have time to look it up now, but there is a rule/code saying unless a fixture is listed for use as a raceway, you can't feed from one to the other. Something similar to this anyway.

However, most strips lights (fluorescent) that I see are fed through or daisy chained.

Here ya go.

410.64 Luminaires as Raceways. Luminaires shall not be
used as a raceway for circuit conductors unless they comply
with 410.64(A), (B), or (C).

(A) Listed. Luminaires listed and marked for use as a raceway
shall be permitted to be used as a raceway.

(B) Through-Wiring. Luminaires identified for throughwiring,
as permitted by 410.21, shall be permitted to be
used as a raceway.

(C) Luminaires Connected Together. Luminaires designed
for end-to-end connection to form a continuous assembly,
or luminaires connected together by recognized wiring
methods, shall be permitted to contain the conductors of a
2-wire branch circuit, or one multiwire branch circuit, supplying
the connected luminaires and shall not be required to
be listed as a raceway. One additional 2-wire branch circuit
separately supplying one or more of the connected luminaires
shall also be permitted.

 

[don_resqcapt19]

That section does not apply to a fixture with a self contained wiring compartment.

I agree that the section does not apply to this installation, but why isn't there a section that does? How is if safe to remove a fixture and open the EGC, but it is not safe to remove a wiring device and open the EGC?

 

[iwire]

I agree that the section does not apply to this installation, but why isn't there a section that does? How is if safe to remove a fixture and open the EGC, but it is not safe to remove a wiring device and open the EGC?

I will go with practical as in 'practical safeguarding'

Picture a recessed fixture in a hard ceiling, how would you design the wiring system that removal of the fixture did not break the grounding?

What are the chances such a fixture would be removed in the first place?




As a side note, most of the drop in fixtures we install have a plate on the back that pops off to make the field connections, this plate has the grounding screw on it. That being the case I can remove the fixture without breaking he grounding to the rest of the circuit.

 

[don_resqcapt19]

I will go with practical as in 'practical safeguarding'
Picture a recessed fixture in a hard ceiling, how would you design the wiring system that removal of the fixture did not break the grounding?
...

All of the fixtures I have ever installed in a hard ceiling were installed with a fixture whip from a j-box that is assessible by removing the fixture.