410.73 -- Luminaire Disconnects -- What The Heck Does It Cover?!?

[RB1]

The change in the 2008 Code was intended to clarify that the requirement applies only to luminaires that utilize double ended lamps. Looking at the sentence in the 2005 Code:

"In indoor locations, other than dwellings and associated accessory structures" - this tells where the requirement applies.

"fluorescent luminaires that utilize double-ended lamps" - this is the type of fixture that the requirement applies (subject).

"and contain ballast that can be serviced in place"-this modifies the subject.

"or ballasted luminaires that are supplied from multiwire circuits and contain ballast that can be serviced in place"- further modifies the subject (redundantly I might add).

"shall have a disconnecting means either internal or external to each luminaire, to disconnect simultaneously from the source of supply all conductors of the ballast, including the grounded conductor if any."-this is the requirement.

In my opinion this is how the panel intended this to be read. It was never intended to apply to luminaires that do not utilize double-ended lamps.

 

[Ladderless]

In my opinion this is how the panel intended this to be read. It was never intended to apply to luminaires that do not utilize double-ended lamps.

I'm really not trying to be argumentative here (honestly). I'm just trying to understand everything.

What's inherently more dangerous about a double-ended lamp? I thought this was primarily about the ballast (And reballasting hot fixtures). Is a ballast in a CFL fixture safer to work on hot?

Why protect one but not the other?

 

[pete m.]

I vote that we abolish the words "qualified person" from the NEC. Where have all the electricians gone?

Pete

 

[dcspector]

I vote that we abolish the words "qualified person" from the NEC. Where have all the electricians gone?

Pete

Retired, quit, found something easier to do, no work ethic, don't want to study, don't want to take a test.....etc. Electrical work is in your heart and mind....eat sleep and drink the trade and if it ain't there get out of it. There are a lot of real (Tradesmen) Electricians still out there but gettin thinner everyday as other trades are as well.

 

[RB1]

Im not sure. None of the original proposals made reference to double-ended lamps. That language did not appear until the comment phase of the 2005 Code cycle.

If I had to speculate I would say that fixtures employing single-ended lamps would not typically be serviced in place. The language was probably chosen to prevent the requirement from being applied to mercury vapor, metal-halide, or other HID type fixtures.

Multiwire circuits would typically be encountered in fixtures that are used as raceways.

Just my opinion.

 

[Ladderless]

The language was probably chosen to prevent the requirement from being applied to mercury vapor, metal-halide, or other HID type fixtures.

That makes a whole lot of sense to me, but raises a new question:

Is "Double-ended lamp" a defined, established term? I see several different definitions, including "A lamp with two separate bases OR POINTS OF ELECTRICAL CONTACT"

A CFL has two ends, albeit ends that are contained in the same base -- But definitely separate points of electrical contact, and (typically) on opposite sides of the base.

Just wondering.

 

[dnem]

That makes a whole lot of sense to me, but raises a new question:

Is "Double-ended lamp" a defined, established term? I see several different definitions, including "A lamp with two separate bases OR POINTS OF ELECTRICAL CONTACT"

A CFL has two ends, albeit ends that are contained in the same base -- But definitely separate points of electrical contact, and (typically) on opposite sides of the base.

Just wondering.

I think it would be logical to interchange "ended" with "bases". . "Double ended lamp" "Double based lamp"

 

[cschmid]

The change in the 2008 Code was intended to clarify that the requirement applies only to luminaires that utilize double ended lamps. Looking at the sentence in the 2005 Code:

"In indoor locations, other than dwellings and associated accessory structures" - this tells where the requirement applies.

"fluorescent luminaires that utilize double-ended lamps" - this is the type of fixture that the requirement applies (subject).

"and contain ballast that can be serviced in place"-this modifies the subject.

"or ballasted luminaires that are supplied from multiwire circuits and contain ballast that can be serviced in place"- further modifies the subject (redundantly I might add).

"shall have a disconnecting means either internal or external to each luminaire, to disconnect simultaneously from the source of supply all conductors of the ballast, including the grounded conductor if any."-this is the requirement.

In my opinion this is how the panel intended this to be read. It was never intended to apply to luminaires that do not utilize double-ended lamps.

So this requirement was intended for double ended lamps which are all varieties of fluorescent lights except the CFL..any other applications?

I vote that we abolish the words "qualified person" from the NEC. Where have all the electricians gone?

Pete

No need to have electricians; with the passage of codes like the one in this discussion which makes it easy for janitors to change out ballast in lights.. there will be no need for electricians..

 

[dnem]

So this requirement was intended for double ended lamps which are all varieties of fluorescent lights except the CFL..any other applications?

If you're on 2005NEC after Jan 1, 08 then you have to install the disconnects for nondwelling CFLs supplied by multiwire HRs. [2005NEC 410.73(G)]

If you're on 2008NEC after Jan 1, 08 then you don't have to consider any types except double-ended lamped ballasted fixtures [nondwelling]. [2008NEC 410.130(G)]

Whatever the application there's exceptions for hazardous [x1], emergency [x2], cord-n-plug [x3], and industrial supervised + written [x4].

2005 410.73(G)x5 / 2008 410.130(G)(1)x5 will probably be the most common installation for all double-ended lamped ballasted fixtures when not supplied by multiwire. . The only difference between the editions is the 2008 elimination of the words, "locally accessible".

I wonder if the normal wall switch will be widely accepted by AHJs as the disconnect. . A single wall switch in rooms with required emergency lighting. . Two or more wall switches in rooms without emergencies. . 24/7 nonswitched nightlights would need a disconnect added, probably in the ballast tray of the first light in the daisychain.

David

 

[RB1]

Dnem,

I am not sure I agree with your interpretation of the 2005 Code. Can you give me an example of a CFL luminaire that can be serviced in place?

 

[cschmid]

If you're on 2005NEC after Jan 1, 08 then you have to install the disconnects for nondwelling CFLs supplied by multiwire HRs. [2005NEC 410.73(G)]

If you're on 2008NEC after Jan 1, 08 then you don't have to consider any types except double-ended lamped ballasted fixtures [nondwelling]. [2008NEC 410.130(G)]

Whatever the application there's exceptions for hazardous [x1], emergency [x2], cord-n-plug [x3], and industrial supervised + written [x4].

2005 410.73(G)x5 / 2008 410.130(G)(1)x5 will probably be the most common installation for all double-ended lamped ballasted fixtures when not supplied by multiwire. . The only difference between the editions is the 2008 elimination of the words, "locally accessible".

I wonder if the normal wall switch will be widely accepted by AHJs as the disconnect. . A single wall switch in rooms with required emergency lighting. . Two or more wall switches in rooms without emergencies. . 24/7 nonswitched nightlights would need a disconnect added, probably in the ballast tray of the first light in the daisychain.

David

are you using the 2008 NEC on disk software? I have ordered mine but have yet to see it after 2 weeks..I do like the code sections and will check it out later on..Would you allow a wall switch as a disconnect..

 

[dnem]

Dnem,

I am not sure I agree with your interpretation of the 2005 Code. Can you give me an example of a CFL luminaire that can be serviced in place?

There might not be one. . Thankfully I don't have to worry about that because Ohio will never enforce that requirement. . We'll be on the 2008NEC on Jan 1, 2008

 

[dnem]

are you using the 2008 NEC on disk software? I have ordered mine but have yet to see it after 2 weeks.

No software, unless my office orders it, I'll just stick with the book.

Would you allow a wall switch as a disconnect..

Yeah, unless I see or hear something that would lead me to believe differently. . I haven't seen the '08 Handbook yet.

 

[RB1]

A wall switch located within sight of the luminaire is OK if the luminaire is not supplied by a multiwire circuit and the operation of the wall switch will not result in the space being left in total darkness.

 

[cschmid]

so the key is that the switch can not leave the room in total darkness..So that disqualifies allot fo installs..

 

[Ladderless]

A wall switch located within sight of the luminaire is OK if the luminaire is not supplied by a multiwire circuit and the operation of the wall switch will not result in the space being left in total darkness.

Doesn't the switch have to disconect both the hot and neutral, then?

 

[LarryFine]

A wall switch located within sight of the luminaire is OK if . . . the operation of the wall switch will not result in the space being left in total darkness.

Does receptacle-supplied lighting qualify?

 

[acrwc10]

These were mentioned earlier in this thread. I saw them today and there good for 3amps. And cost about $1.50 each. very simple to use.

View attachment 1022

 

[acrwc10]

Sorry I forgot to mention they are made by IDEAL.

 

[LarryFine]

View attachment 1022

Hmmm. Interesting to note that the design shields the contacts on both halves, perhaps due to the shock hazard mentioned in the charged-capacitor discussion.