UL Recognized vs. Listed

[JDBrown]

This morning I received a lighting plan from an Architect. It shows several LED fixtures (or luminaires, if you prefer) supplied by remote power supplies. When I looked up the power supplies, I discovered that they are UL Recognized, not UL Listed. I've run into this issue before, but I'm sure that I completely grasp what's going on.

As I understand it, the power supply would need to be UL Listed in order for the Electrician to be able to install it in the field, while a UL Recognized power supply would have to be put into some type of Listed assembly by a "UL Shop" in order to be acceptable. Is that correct? If not, what is the difference between UL Listed and UL Recognized?

Other questions:
What is a "UL Shop"? I've seen that term on these forums several times, but I'm still not quite clear on what it means.
Does the LED assembly need to be UL Listed as well, or just the power supply?

 

[GoldDigger]

This morning I received a lighting plan from an Architect. It shows several LED fixtures (or luminaires, if you prefer) supplied by remote power supplies. When I looked up the power supplies, I discovered that they are UL Recognized, not UL Listed. I've run into this issue before, but I'm sure that I completely grasp what's going on.

As I understand it, the power supply would need to be UL Listed in order for the Electrician to be able to install it in the field, while a UL Recognized power supply would have to be put into some type of Listed assembly by a "UL Shop" in order to be acceptable. Is that correct? If not, what is the difference between UL Listed and UL Recognized?

Other questions:
What is a "UL Shop"? I've seen that term on these forums several times, but I'm still not quite clear on what it means.
Does the LED assembly need to be UL Listed as well, or just the power supply?

A UL shop is a company that has paid to be checked out and then listed by UL. Their listing makes them a creator of assemblies who is usually therefore licensed to apply a UL sticker to the result.

For field installation, either the whole assembly or all of the component parts you put together need to be listed.
As you noticed, the separate components are often only available as recognized rather than listed, and an inspector could fail you on that if he chose.
Another concern will be whether the power supply is small enough to be recognized as limited power output, allowing you more flexibility in wiring methods.

 

[mgookin]

We're a manufacturer. The following comes from one of our listing reports.

Recognized Component - A component part, which has been previously evaluated by an accredited certification
body with restrictions and must be evaluated as part of the basic product considering the restrictions as specified
by the Conditions of Acceptability.

Listed Component - A component part, which has been previously Listed or Certified by an accredited
Certification Organization with no restrictions and is used in the intended application within its ratings.

Unlisted Component - A part that has not been previously evaluated to the appropriate designated component
standard. It may also be a Listed or Recognized component that is being used outside of its evaluated Listing or
component recognition.

Critical Features/Components - An essential part, material, subassembly, system, software, or accessory of a
product that has a direct bearing on the product’s conformance to applicable requirements of the product
standard.

We are a UL shop but we're only allow to label what it is we are approved to label. In our case, we make outdoor light controls which have been listed.
That's the only product we can put the label on.

I'd like to suggest you call the manufacturer of the "recognized component" and ask them under what conditions you can create an "assembly" using their product.

 

[Jraef]

This morning I received a lighting plan from an Architect. It shows several LED fixtures (or luminaires, if you prefer) supplied by remote power supplies. When I looked up the power supplies, I discovered that they are UL Recognized, not UL Listed. I've run into this issue before, but I'm sure that I completely grasp what's going on.

As I understand it, the power supply would need to be UL Listed in order for the Electrician to be able to install it in the field, while a UL Recognized power supply would have to be put into some type of Listed assembly by a "UL Shop" in order to be acceptable. Is that correct? If not, what is the difference between UL Listed and UL Recognized?

Other questions:
What is a "UL Shop"? I've seen that term on these forums several times, but I'm still not quite clear on what it means.
Does the LED assembly need to be UL Listed as well, or just the power supply?

As GoldDigger said, a UL shop is a facility that is listed and inspected by UL to do custom assemblies. Their process of assembly and the components they use are what is evaluated, not the end product. So they are able to assemble custom products using UL procedures, then apply a UL listing label to it as a proxy for UL themselves.

As part of that service, a UL listed shop can use UL Listed components freely (for their intended use). If they want to use UL Recognized (backward UR) components they can, but they must "add them to their procedure" and submit the intended use to UL, then pay an evaluation fee to UL (usually every quarter). That is usually because, a UR component is NOT intended to be used all by itself, it must be used WITH something else to make it completely safe. Sp for example, most if not all of the little "ice cube" plug in relays are not UL Listed, they are UR, because they MUST be used with a socket. The socket too is not UL Listed, it is UR because it MUST be used with the relay. Together they can be used by a UL Shop in making a custom control panel, but the shop must submit a list of the UR components and describe how they are going to be used, together in that case.

I have no idea if there is such a thing as a UL Listed Assembly Shop for lighting fixtures, I am only familiar with UL508A which is for control panel builders. But even if there is such a thing, they would have to carefully evaluate the UL file associated with that recognized component to see what it is that it must be used in conjunction with. If you are lucky, it might be something as simple as it being mounted into a specific enclosure or one with a specific air volume for the heat rise testing. If so, you might be able to take it to a UL508A panel shop and have them mount it and give you a UL label on the assembly. Barring that, it might still be totally incapable of being used stand-alone in the field as a remote power supply, even by the fixture mfr.

Sometimes consultants say that they want things that cannot be done legally. You just have to 'spain it to them.

 

[petersonra]

The explanation about listed and recognized parts is sort of true, more or less.

UL508a has a long list of both listed and recognized parts that can be used for specific purposes contained in table SA1.1.

It has a key that refers to a specific paragraph, a UL standard that the part has to meet, the category control number, and any notes.

here are a couple of examples.

14.2(a)
Recognized grounding bar kits
UL 67, UL 891
QEUY2
Procedure described only

this means you can't use these in a UL508a panel unless they get added to your procedure.

14.2(b)
Listed Grounding and Bonding Equipment
UL 467
KDER
Grounding terminal shall be suitable for the conductor size required by 15.1

here is a case where both listed and recognized components with the same UL Standard can be used.

21.1.1
Listed Industrial Control Panel Enclosure with Ventilation Opening
UL 508A
NITW
Location of ventilation opening with respect to components installed within enclosure shall comply with 21.2

21.1.1 Recognized Industrial Control Panel Enclosure with integral Ventilation Opening
UL 508A
NITW2
Location of ventilation opening with respect to components installed within enclosure shall comply with 21.2

As best I can tell, the suffix "2" on the category control number indicates a recognized part.

SA1.2 says this

Where a Listed device is provided in an industrial control panel and specific component
requirements are not described in this standard, any Listed component is able to be used.

So if I need a part that is not in table SA1.1, I can use any listed part. Suppose I need to add a refrigerator. They are not in table SA1.1, so I could use any listed refrigerator.

 

[renosteinke]

The 'recognized component' mark is completely irrelevant to the electrical trade.

Let me use an example of where the RC mark is meaningful, and perhaps you'll understand.

Let's assume I make stereos, and I want my new model to be UL listed.

If I submit the stereo complete, the stereo and its' components will be subject to a variety of tests. I get to pay for all those tests. So, for example, I'll have to pay for a dielectric withstand test on the transformer in the power supply.

If I submit the same stereo, but that transformer has the RC mark, the folks at UL can say "we already did the test- no need to charge this guy."

Later on, in production, let's say my transformer supplier goes out of business. Or, perhaps, he can't supply all I need for my wildly successful new "I-Bose stereo." (Apologies to the trademark holders). My replacement transformer will have to be submitted to UL for evaluation - unless, of course, it has already been evaluated. The RC mark is evidence it had been evaluated.

Now, for you and me, cobbling together a relay box for the Ansul system -or making a custom light fixture, or whatever- the presence of RC-marked parts has no meaning at all. Their presence says nothing about whether our 'product' would pass testing, or is even safe. As with listed products, the RC mark says nothing about the quality or usefulness of the product.

The RC mark is used for items that are, by themselves, useless. Only when assembled together with other parts can something useful be made. This distinction was blurred a bit with the advent of the fluorescent light. This was simply because there was no "recognized component' category when ballasts came out. The listing of ballasts was the subject of intense debate within UL, and ultimately led to the creation of the recognized component program.

"Listed shops" are a completely different subject. Suffice it to say that nearly everyone who makes UL-listed products is NOT a 'listed shop.'

 

[cadpoint]

14.2(b)
Listed Grounding and Bonding Equipment
UL 467
KDER
Grounding terminal shall be suitable for the conductor size required by 15.1

Ah, you should have listed 15.1.

Negating the shop aspect.

Ok, Frankly I thought of an Electrican using listed material, thus my statement.

Second thought was where is average joe electricain building and assembley of listed material and not treading into UL Requirements....