its the battle of the LD vs the EE (yet again)

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What's the official on this (if there is one); it's the same issue that occasionally occurred with low voltage lighting using remote power supplies, but with the proliferation of LED lighting, has become exponentially more of an issue?

The code defines a lighting fixture as a complete system: including the light source, its housing, its power supply, and everything in between...
this includes remote power supplies.

The Electrical Engineer says: "yes, I'm responsible for power distribution ... to the light fixture, after that, it's out of my hands." (i.e. when a fixture has a remote power supply, I'm not doing the low voltage cabling between the remote power supply units (PSUs) / (drivers) and the fixtures. (this occasionally can be a substantial task.)
The Lighting Designer says: the connection between the PSUs and the fixture is power, and the issue is how it is distributed (what gauge wire, run in what manner, etc.); in other words, it is "power distribution", and as such, is something that needs to be submitted by a licensed Electrical Engineer (and sealed on the drawings). Consequently it is not the responsibility of the the LD, but of the EE who is licensed (in other words: "not us")"

(...I've know many, many LDs and never have i heard of one, except when affiliated with a larger MEP Firm, where any license is kept, never mind one acceptable to the relevant jurisdiction.)

This is becoming a huge bone of contention, and at best a disputable scope -gap that irritates (to say the least) the owner's rep.

Any thought, reflections, or further direction would be held in high esteem.

Mark
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I am inclined to agree with the engineer.

I guess it would boil down to how is this kind of thing typically handled in the jurisdiction this project is in?
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
I would side with the engineer on this issue:happyyes:, and not just because I am an engineer:happyno:. Saying that the wires from the remote power supply to the lamp are “power” is oversimplifying the situation.

To my way of thinking, the lighting designer will coordinate with the architect to select and layout the luminaires. I will echo their layout on my lighting floor plan. I will then add the control components (switches, occupancy sensors, daylighting sensors, etc.) and the circuiting. If the selected luminaire includes a power supply that is remote from the lamp, I will bring power to the remote power supply. That is the location of the “lighting outlet,” and is the point at which the “premises wiring system” ends and the “luminaire” begins. Take a look at the definition of “premises wiring system,” and you may see why I see this issue the way I do.

All that notwithstanding, if the owner (or whoever is paying my bill) wants me to include the design for the wiring between the remote power supply and the lamp, I can do that. We would just need to be clear on the establishment of my scope of work, and the basis for my fee. But I do not believe the design for this portion of the project requires a drawing signed and sealed by a PE. I also do not believe the lighting design process falls within the “practice of electrical engineering,” and therefore it too does not require a PE’s seal.

Here is my question: Is there a difference in the licensing requirements for the person who will install the circuit from the breaker panel to the lighting outlet and the person who will install the wires between the remote power supply and the lamp? I think there is, at least in my state. Here, a person can obtain a “specialty electrician” license for “limited energy systems.” My understanding is that such a person could do the second task, but not the first. I see this as supporting evidence for my point of view. You don’t need to be licensed to install the branch circuit, in order to have the authority to install the low voltage wiring. Similarly, you don't need to be licensed to design the branch circuit, in order to have the authority to design the low voltage wiring.
 

jcbabb

Member
Location
Norman, OK, USA
I would think that the manufacturer of the light fixtures would be able to help with this as well. I would think that these low voltage designs would not need to be sealed.

Can you give us an instance where this has been an issue?
 
I guess my question is: does the wiring between the remote power supply and the actual fixture need to be on a stamped and sealed drawing? I would state that because it is covered under the NEC, it does.

And then extend that to ask if all wiring within a single entity (a structure, complex, or portion of) should be under the jurisdiction of a single engineer (having multiple EE scopes within a single area certainly leads itself to conflict in both omission and conflicting redundancy.) I suspect that the code is silent on this issue (?)
Having said that, (that it should be one or the other, but not both) should the owner relinquish responsibility to the unlicensed Lighting Designer, or inversely, should the EE expand the definition of their scope, and take responsibility for the whole, authorizing the document set under a single stamp?
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
I would side with the engineer on this issue:happyyes:, and not just because I am an engineer:happyno:. Saying that the wires from the remote power supply to the lamp are “power” is oversimplifying the situation.

To my way of thinking, the lighting designer will coordinate with the architect to select and layout the luminaires. I will echo their layout on my lighting floor plan. I will then add the control components (switches, occupancy sensors, daylighting sensors, etc.) and the circuiting. If the selected luminaire includes a power supply that is remote from the lamp, I will bring power to the remote power supply. That is the location of the “lighting outlet,” and is the point at which the “premises wiring system” ends and the “luminaire” begins. Take a look at the definition of “premises wiring system,” and you may see why I see this issue the way I do.

All that notwithstanding, if the owner (or whoever is paying my bill) wants me to include the design for the wiring between the remote power supply and the lamp, I can do that. We would just need to be clear on the establishment of my scope of work, and the basis for my fee. But I do not believe the design for this portion of the project requires a drawing signed and sealed by a PE. I also do not believe the lighting design process falls within the “practice of electrical engineering,” and therefore it too does not require a PE’s seal.

Here is my question: Is there a difference in the licensing requirements for the person who will install the circuit from the breaker panel to the lighting outlet and the person who will install the wires between the remote power supply and the lamp? I think there is, at least in my state. Here, a person can obtain a “specialty electrician” license for “limited energy systems.” My understanding is that such a person could do the second task, but not the first. I see this as supporting evidence for my point of view. You don’t need to be licensed to install the branch circuit, in order to have the authority to install the low voltage wiring. Similarly, you don't need to be licensed to design the branch circuit, in order to have the authority to design the low voltage wiring.

In New Jersey, the answer is "no". Unless you are running at less than 10 volts, you need to be a licensed electrical contractor to wire up from the PSU's to the actual luminaire. I can't imagine any AHJ around here not requiring that the circuits appear on a signed and sealed electrical drawing.
 

iwire

Moderator
Staff member
Location
Massachusetts
I guess my question is: does the wiring between the remote power supply and the actual fixture need to be on a stamped and sealed drawing? I would state that because it is covered under the NEC, it does.

I agree and will just add this is not up to the EE or LD to decide, this will be about what the AHJ requires.
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
I guess my question is: does the wiring between the remote power supply and the actual fixture need to be on a stamped and sealed drawing? I would state that because it is covered under the NEC, it does.
What the NEC covers and what any jurisdiction might require an engineer to supervise are two completely separate things. I would only restate the opinion that the wires between the remote power supply and the lamp are not part of the "premises wiring system."
And then extend that to ask if all wiring within a single entity (a structure, complex, or portion of) should be under the jurisdiction of a single engineer (having multiple EE scopes within a single area certainly leads itself to conflict in both omission and conflicting redundancy.) I suspect that the code is silent on this issue (?).
It is silent, and it should remain silent. I have no issue with multiple engineers working on the same project, so long as there is a clear delineation of responsibilities.
Having said that, (that it should be one or the other, but not both) should the owner relinquish responsibility to the unlicensed Lighting Designer. . .?
Please don’t disparage lighting designers by calling them “unlicensed,” as though that puts them at a lower level than any of us. Their profession is worthy of high regard. They are not licensed because they are not practitioners of engineering.
. . . or inversely, should the EE expand the definition of their scope, and take responsibility for the whole, authorizing the document set under a single stamp?
I already said I would willingly undertake this task, so long as the owner and my company came to an agreement on scope, schedule, and budget.

But let me STOMP :blink:(but just lightly! :happyyes: ) on your use of the word “authorizing” in this sentence. That is not what a PE’s seal does. It does not constitute approval of the design or authorization of the work. The PE seal says one thing to the entire world, and it says no other thing. What it says is, “This work was done by me, or under my supervision.” It is taking responsibility for the design, and that is all it is doing.



 

iwire

Moderator
Staff member
Location
Massachusetts
Ok, I have a new building being designed, I hire an EE to design the wiring system.

They show emergency battery units around the building but no wiring to the remote heads

When I ask the EE about it they tell me those wires are not their job to layout or specify.

This makes no sense and if I was paying the bills the EE would be out of a job
 

iwire

Moderator
Staff member
Location
Massachusetts
What the NEC covers and what any jurisdiction might require an engineer to supervise are two completely separate things.

Generally those go hand in hand.


I would only restate the opinion that the wires between the remote power supply and the lamp are not part of the "premises wiring system."

And I will state the opinion that really depends on the specifics of the equipment.

The wiring between say a low voltage transformer and the low voltage lighting it supplies is often part of the premises wiring system'


The PE seal says one thing to the entire world, and it says no other thing. What it says is, “This work was done by me, or under my supervision.” It is taking responsibility for the design, and that is all it is doing.

And if you are hired to design the wiring system it should be the entire system, not just what you feel like doing. :D
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
In New Jersey, the answer is "no". Unless you are running at less than 10 volts, you need to be a licensed electrical contractor to wire up from the PSU's to the actual luminaire. I can't imagine any AHJ around here not requiring that the circuits appear on a signed and sealed electrical drawing.

For 120V single phase circuits, I have mostly seen them shown as an entry on a PB drawing. I have never seen anything beyond that on a sealed drawing. I can't say that I see a lot of sealed drawings of that type though. There usually is a diagram of some sort, but it is not usually sealed IME.
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
Ok, I have a new building being designed, I hire an EE to design the wiring system.
I see a subtle difference between your example and the OP's example. In your example, I would have had discussions with the owner on the subject of how egress lights were to be designed. I would have known that there were centralized batteries that served multiple heads, and I would have specified the related components. Finally, I would have included that fact in my scope, schedule, and budget agreement. In the OP's example, I infer that the EE was hired to design a premises wiring system that included lighting outlets and control devices (switches, occupancy sensors, etc.). But the EE was not hired to select the light fixtures. So when the lighting designer chose fixtures that had remote power supplies and LV wiring to the lamps, that additional LV wiring was outside the EE's original scope of work. The right thing to do at that time would be to inform the owner of the situation, and ask the owner how they want it to be handled. The wrong thing (and this is also true in your example) would be for the EE to ignore the situation and assume that everyone already knows that someone else will be responsible for the LV wiring.

I acknowlege that the question of whether the LV wiring needs to appear on a design drawing that is sealed by a PE is a question that might need to be answered by the AHJ. For my part, I would not take any exception to that wiring being done by an electrician without that person asking for instructions from the EE.

 
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