low voltage lighting

[sparkmantoo]

okay here is a good one. you have a handmade fixture. it operates at 24vdc. you have two conductors that come out of a j-box. these wires are single conductors, 24awg, looks kind of like a coaxial cable. they terminate to the fixture by means of a set screw connection. these wires are the means of support for this fixture. this fixture is pretty heavy and rather large. is this legal to (1) use the wires as a means of support, (2) use a coaxial cable to feed this fixture, (3) have a fixture that is NOT listed (homemade),and(4) is this a moot point because it is low voltage. i await everyones reply. the articles that i can reference to are 410.28(f) and 411.

 

[hbiss]

Re: low voltage lighting

If the wiring is not concealed and the transformer is cord and plug connected to a receptacle I don't believe there is anything that would cover this in the NEC. I certainly wouldn't want to be around it though!

 

[tom baker]

Re: low voltage lighting

Just because its "low voltage"doesn't mean there is no hazard with its use. However there is generally little hazard, and systems under 30 V are not considered energized by the NEC if they are (from art 411):
411.2 Definition.
Lighting Systems Operating at 30 Volts or Less. A lighting system consisting of an isolating power supply operating at 30 volts (42.4 volts peak) or less, under any load condition, with one or more secondary circuits, each limited to 25 amperes maximum, supplying luminaires (lighting fixtures) and associated equipment identified for the use.
411.3 Listing Required.
Lighting systems operating at 30 volts or less shall be listed for the purpose.

Art 411 refers to a listed lighting system, IE all the parts are part of a system identified by the mfg for the use.

See Art 100 definitions of Listed and Identified.
And see 110.3(B)

 

[pierre]

Re: low voltage lighting

As Tom has mentioned, 411.3 requires a listed system. This whole setup you have descibed sounds like a shoemaker installed it. I would tell the owner they have a hazardous situation and replace all of the improper wiring.

There are instances where a fixture (luminaire) can be supported by a wire, it should be listed for the purpose.
Coaxial cable is not listed for low voltage lighting.

Pierre

 

[sparkmantoo]

Re: low voltage lighting

here is the deal. a custumer hired a lighting engineering firm to lay out lights in a home. it's a 10 million dollar home but that is besides the point. the lighting guru that designed and made the fixture did not have the luminaire listed. he says it is not necessary. art. 411.3 says the SYSTEM must be listed. if that is the case then why can't i make lv fixtures in my garage and sell them at will. in my opinion, art.410.28(f) clearly states that the weight of the fixture shall not put tension on the conductors. articles 410 & 411 are to be used in conjuction with each and one should not supercede the other especially when it comes to safety. art 410 also has a section where it says luminaires over 6lbs and 16 inches cannot be supported by the screwshell of the lampholder and a section where it says other applicable articles apply.
our solution was to inform the customer that we installed a listed system up to the j-box, and that the fixture that they purchased was not listed with the system, and that the potential for the fixture to fall by the way it was designed is very high and that the lighting guru was to take full responsibility in the event of a problem. the low votage lighting situation is getting way out of hand. we now have to go by a small section in the code that doesn't address the potential of situations that i have just described. oh and by the way, one fixture did fall, and another one burnt up at the connection and we were blamed for it. even though we did not make the connections and hang the fixtures, we hold the electrical permit for the job and it all falls under our responsibility. what a weird world we live in.

 

[iwire]

Re: low voltage lighting

I have installed many low voltage lighting fixtures that the fixtures have been directly supported by the supply conductors, But the entire assembly has been UL listed nothing home made etc.

I would say as Tom pointed out it must be a listed assembly.

The NEC took the time to specifically say

411.3 Listing Required.

Lighting systems operating at 30 volts or less shall be listed for the purpose.

Have you asked the AHJ if they will aprove this homemade fixture?

[ August 10, 2003, 10:59 AM: Message edited by: iwire ]

 

[sparkmantoo]

Re: low voltage lighting

yes we have and they said it is low voltage and there is nothing that they can do. it is a sad day when our government officials hands are tied do to a grey area. the code should read "no luminaire shall be supported by the supply conductors regardless of the voltage". and that i believe says it all.

 

[pierre]

Re: low voltage lighting

Sparkmantoo
It can get very frustrating on a job when the owner believes the Engineer is smarter than the installer. But... because you hold the permit, you have several options legally.
The one I would exercise is: On the permit state that you did not install the low voltage lighting, work performed by others.
Let the owner know you are doing this in writing, as well as the municipality you pulled the permit in. Now you have a permanent copy on record, should anything go wrong.
A couple of years ago I also had a 'fair size' job with a bunch of 'unlisted' fixtures. This is how I treated the situation. It caused a large problem on the job for a 'month', but now it is on record. The contractor on that job has not hired me again, oh well! I am still here.

BTW - the building department read my statement and did not want to be responsible for the fixtures. It was settled by having the owner sign an affidavit saying they were aware of the potential problem and would assume all responsibility of the fixtures. It took a month, because the village had their lawyer draw up the document.

Pierre