NEC vs UL Branch Circuit Definition for sign

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EDesigner

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I have a question concerning the definition of a branch circuit in the eyes of the NEC and how it correlates with how UL might interpret it. I am referring specifically to a piece of equipment listed under UL48 (Electric Signs). The electrical installation external to the sign would fall under Article 600. I will be referring specifically to 600.5. The electric sign is not incandescent, fluorescent, or neon. So, I would say that 600.5(B)(1) & (2) do not apply to this product.

However, UL48 16.1A dictates ?Signs shall not be connected to a branch circuit exceeding 20 amperes.? The manufacturer of this sign claims that they meet their UL listing requirements because the incoming wires are a ?Feeder? and not a ?branch circuit? as that clause literally states.

A little info on the sign: The incoming service lands to a termination panel which incorporates 20A single pole breakers that then distribute 20A single pole circuits out to the various power supplies and loads within the sign. The incoming circuit to the sign is sourced from a load center containing a three pole 50A breaker. This incoming circuit from that distribution panel is a three phase 208Y/120V, 4 conductors + gnd.

Thoughts?
 
In order to be a feeder, the panel at the sign has to be listed:
We start with the sign is building or structure, per the Art 100 definition.

225.31 Disconnecting Means.
Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure.

225.36 Suitable for Service Equipment.
The disconnecting means specified in 225.31 shall be suitable for use as service equipment.

SUSE means there is a bonding jumper that can be installed and the panel would be labeled as such. If not, then its supplementary overcurrent protection, fed by a branch circuit.
 
Thanks for the input thus far. I think maybe I need to clear this up a little more.

Let's say this sign is located in a parking lot, a fair distance away from the building. A transformer is set at the sign location, disconnect on the immediate secondary. This disconnect feeds into a 200A distribution panel. This panel holds the 50A 3p breaker that feeds from the distribution panel, through conduit up about 40 feet and piped straight into the sign.

Once inside the sign, the 50A conductors terminate into an internal termination block, which then distributes through multiple 20A breakers to the various circuits within the sign. Please refer to the following sketch.

Is the indicated circuit a branch circuit or a feeder? In NEC's eyes? How about in UL's eyes, according to the UL reference from the original post?
3407405154


Hope that picture loads...

Thanks again for all the input.
 
What you have circled is a feeder.

Here is the definition of feeder from Article 100 of the NEC.

"Feeder. All circuit conductors between the service equipment, the source of a separately derived system, or other power supply source and the final branch-circuit overcurrent device."

Chris
 
raider1 said:
What you have circled is a feeder.
Click to expand...
Definitely.

EDesigner said:
So, are we considering the "branch circuits" to be the sign's internal wiring?
Click to expand...
Whether they are or not may depend on whether the NEC has any jurisdiction inside the sign.

But, the fact that the internal panel is supplied by a breaker greater than its 20a breakers makes its supply a feeder.

That's my take, anyway. I am curcious as to why it matters what it's called.
 
First of all, thanks for the info from everyone.

LarryFine said:
Definitely.

That's my take, anyway. I am curcious as to why it matters what it's called.
Click to expand...

As for why it matters....well, it really is a case of splitting hairs, in my opinion. But, in order for the sign to meet it's UL listing requirements, it must "not be connected to a branch circuit exceeding 20A." So, from the UL perspective, if that circuit is considered a "branch circuit", then we would need to feed the sign in the drawing with 5, 20A 2w+gnd circuits instead of the single 50A 4w+gnd "feeder". Otherwise, we would violate the UL listing. So far, I have not been able to get a solid definition of what UL considers branch circuit and feeder. But, they typically seem to reference the NEC for those types of items.

I had been leaning towards the definition of feeder as most of the responses pointed me to. But, the delineation between the NEC jurisdiction and UL jurisdiction seemed fuzzy. I did not know whether the sign would essentially be a "black box" load from the NEC's point of view and not take into account any internal circuit OCP. Or, if the NEC would consider those 20A OCP devices, after the termination lugs to still fall under their definition.

It does seem like somewhat of a ridiculous issue to me. The current setup as the drawing shows appears perfectly safe from all perspectives. It is really a case of splitting hairs over terminology.
 
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