Patient care area lighting

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necbuff

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There is a new lighting system out that operates on 70V. They make them in cans and lay-in form. It has a xfmer that mounts onto a 4 square box above the light (at line voltage). The current is very low. Juno modu-lites are the name. There is then a nm jacketed cable (looks similar to a CAT 5 from the outside, never opened one up) and it plugs into the module (xfmer). The argument is the Rep says it can be placed in a patient care area because of the voltage (being a class I or II I don't remember which). I say it must comply with 517.13 (A) and (B). Under other conditions, it is supported by j-hooks or rings like data cables.

He is trying to say since it is less than 100 volts it doesn't have to have a metallic sheath or raceway listed as a ground fault return path. My case is it doesn't matter. The only exception is you may omit the insulated EGC where over 7 1/2' and where switches are are located outside the patient care area.

His position is due to the class, it does not have to comly nor is a lighting fixture fixed equipment. My case is if a fixture is not fixed equipment, luminares would not be mentioned in exception no.2. Any thoughts?

[ November 26, 2005, 06:45 PM: Message edited by: necbuff ]
 
Re: Patient care area lighting

Dave, Doesn't (B) and exception(s) 1 & 2 only apply to the the insulated EGC in (B)? (A) has no exceptions. My thinking was the wiring method would still need to comply with (A) in all cases, but the ECG could be omitted where 100V or less, or the exceptions to (B) apply. The soares book on grounding addresses this very issue, but the class of this new fixture is what was of concern. I can not find any exception to (A). I have looked in 725 as well. I have tried to be open minded to the issue but have yet to find an exception to the wiring method itself.

[ November 27, 2005, 10:06 AM: Message edited by: necbuff ]
 
Re: Patient care area lighting

Kenny 517.13 applies to branch circuits.

From your description, IMO the branch circuit stops at the transformer.
 
Re: Patient care area lighting

I think that Bob brings up an interesting point. In fact the branch circuit by definition, stops at the transformer that supplies these particular lights.

I can see how there is a question with this lighting system, as there can be considerable amount of wiring extending from the transformer to the fixture itself. My understanding is this is listed assembly for the lighting, and it may be exceptable. I would contact UL and see what they have to say about this application for the lighting system in question.
Going strictly by the NEC, I would say the manufacturer is correct in that this would be acceptable.


In general, this new lighting system is going to create quite the stir in our industry, I think in a short amount of time you will see this take off like a jet. - JMHO
 
Re: Patient care area lighting

Kenny,
Yes, that is what I meant with #2. I agree with Bob and Pierre as to the branch circuit wiring and the "operating over 100V" part.
My guess is the transformer is an isolated system and the ciruit conductors for it would not need grounding. If this were true, wouldn't it be a safer system than a grounded one?

[ November 27, 2005, 11:46 AM: Message edited by: websparky ]
 
Re: Patient care area lighting

I think it would be a safer system for the most part. This system is new and obviously wasn't around when the article was written. But you see the concern. I do think it needs to be addressed. As for the branch circuit, is there overcurrent protection in the transformer? I don't know but wouldn't that be what decides whether or not it is, thinking of article 100? As suggested, a close look at the UL information could possibly shed some needed light. We need to come to some conclusion because they will probably grow in popularity and we need to know.
 
Re: Patient care area lighting

Originally posted by necbuff:
As for the branch circuit, is there overcurrent protection in the transformer? I don't know but wouldn't that be what decides whether or not it is, thinking of article 100?
Click to expand...
Kenny I think the OCP location is a non-issue in this case.

If I understand the equipment you have the outlet at the end of the NEC branch circuit is the box where we feed the transformer.

Once we hit that transformer UL takes over the internal / interconnect wiring of this listed for the purpose equipment.
 
Re: Patient care area lighting

75 volts 50,000 HZ I wonder what that feels like?
Is it extremely dangerous system or barely dangerous.

I don't have any experience with 50,000 HZ
 
Re: Patient care area lighting

"they will probably grow in popularity and we need to know."

I believe the popularity of this system will be with the building owners, as once the system is installed, I do not see the need to have an EC add to the load side wiring.

I do not know for sure, but the transformers may have integral protection.
 
Re: Patient care area lighting

Thanks for the input. Some good points have been made. I have a call in to Mark Ode at UL. Maybe he can help clarify.

[ November 27, 2005, 06:22 PM: Message edited by: necbuff ]
 
Re: Patient care area lighting

My first thought about this 'dilemma' is that the branch circuit ends at the 4 square box with the transformer. The NEC seems to agree also. I imagine Juno worked out the grounding/bonding issues in order to get a UL listing. And the NEC wouldn't ever have us replace factory wiring unless the manufacturer instructs us to. So unless the manufacturer restricts these from being installed in a patient care area, I believe that it can be done.
 
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