Solar disconnect

[Swamp_Sparky]

My question is, would this component be acceptable or not in a US installation, or would it be up to the AHJ?

 

[c_picard]

Is that close up a component of a larger combiner box?
I see "recognized" but not "listed"...

I'll watch this thread cause I'm curious, but I think this is up to the AHJ.
Keep in mind the UL experts may not be watching the Solar Channel(PV Forum)!

 

[Swamp_Sparky]

It is the outer cover of a 250a 1000vdc disconnect. I didn't photograph the entire unit because all markings are on that label.

Edit: I'll take a full picture of the unit installed tomorrow. The engineer that designed the system is already mad at me - might as well go for broke.

 

[Marvin_Hamon]

Solar disconnect

It's interesting that this is a 1000V disconnect and UL 98 only goes up to 600V.

UL Recognized Components are intended to be used to build UL listed devices and not to be used on their own. So if this is used as part of a UL listed DC combiner box for instance it would be fine. Most likely it could only be used up to 600V though.

 

[Swamp_Sparky]

Here are a couple more photo's of the entire cabinet:

 

[K8MHZ]

Why wouldn't it be acceptable?

Telergon seems to be a large and reputable maker of this type of gear. The work looks very professional.

If you are concerned about the 1000 volt rating, that is a max. I don't know of any requirement that limits the max rating of a device. The US 600 volt limit is for the actual voltage, not the limits of the device.

Look at it this way. 210 limits voltages in dwellings to 120 volts in certain instances. We still can use NMS with a 600 volt rating for those circuits because the rating of the cable is not the actual voltage being used.

 

[jaggedben]

Why wouldn't it be acceptable?

Well, if it's not actually listed, a lot of AHJs would have a problem with that.

 

[K8MHZ]

Well, if it's not actually listed, a lot of AHJs would have a problem with that.

They can have all the problem they want, but unless they can cite a requirement for PV discos to be listed, they have to accept it. I find no such requirement.

That doesn't mean it doesn't exist. If you can cite otherwise, I would be glad to have been enlightened. That's mostly why I frequent this forum.

 

[Twoskinsoneman]

They can have all the problem they want, but unless they can cite a requirement for PV discos to be listed, they have to accept it.

It SHOULD be so but sadly it is not.

110.2 Approval. The conductors and equipment required
or permitted by this Code shall be acceptable only if
approved.

Approved. Acceptable to the authority having jurisdiction.

 

[iwire]

My question is, would this component be acceptable or not in a US installation, or would it be up to the AHJ?

We are not looking at a disconnect, we are looking at entire piece of equipment so the question is if the entire piece of equipment is UL listed?

If the entire unit is listed, the listing of that one component is irreverent.

Why wouldn't it be acceptable?

I am betting that entire assembly does fall under this and would have to be listed as a whole.

690.4(D) Equipment. Inverters, motor generators, photovoltaic
modules, photovoltaic panels, ac photovoltaic modules,
source-circuit combiners, and charge controllers intended
for use in photovoltaic power systems shall be identified
and listed for the application.

 

[augie47]

Locally, our approach would be the same as Iwire stated. Per TN State Code, we would be looking for a NRTL label on the assembly, not the components.

 

[Swamp_Sparky]

This, from the PM and the engineer who designed the assembly:

"We're going to have it UL certified in the field. It's not your concern."

Ok then. Although I doubt either of them know what that's going to cost. Should take a nice whack out of their profit margin. But, like I was told - not my concern.

 

[BillK-AZ]

UL

UL

There are three basic paths to follow for such assemblies:

• Full UL1741 listing for commercial products (inverters, combiners, etc.)
• Custom Certification to UL508A
• UL Field Evaluation/Certification

Control panels such as described in the start of this thread can be assembled by UL recognized shops that apply all the requirements of UL508A. Basically build it in a controlled environment using Listed and Recognized components, used in accordance with the listing or recognition of the components and the assembly rules.

Field Evaluation is now often used to re-certify equipment that has been modified such as adding a line-side connection to a service entrance that was not provided for by the manufacturer. Rather expensive, with travel costs, etc. Generally requires per-approval of the intended modifications and proof that the equipment meets all requirements of its listing before the modifications are made.

 

[Django]

A regonize component has some conditions of acceptability or limitation. So i guess an inspector will probably try to check that in the file of the product to see if those limitations were respected. A solution could have been to use ul listed components as opposed to recognized. Please note also that UL98B is the standard for solar disconnects and goes up to 1000VDC. uL category code is whva.

 

[ChicagoCubs]

UL98B compliant

UL98B compliant

You are right, I find the labeling from Telergon confusing.
As stated by Django, it seems that only Socomec is listed with a UL98 and UL98B solution for the PV systems. I saw them quite often last year at the SPI exhibition in L-A with the combiner box manufacters and also integrated in inverters like SMA or Satcon.

 

[ChicagoCubs]

They can have all the problem they want, but unless they can cite a requirement for PV discos to be listed, they have to accept it. I find no such requirement.

That doesn't mean it doesn't exist. If you can cite otherwise, I would be glad to have been enlightened. That's mostly why I frequent this forum.

Well, there is a standard for the PV disconnect and it is the UL98B one. That standard allows your PV disconnect to be UL listed for application up to 1000VDC. That standard is different from the UL98 one. For example, the number of operations are different, the time/constant for the test is 1ms and the temperature rise is only 40?C in the UL98B.

 

[Marvin_Hamon]

They can have all the problem they want, but unless they can cite a requirement for PV discos to be listed, they have to accept it. I find no such requirement.

That doesn't mean it doesn't exist. If you can cite otherwise, I would be glad to have been enlightened. That's mostly why I frequent this forum.

In my experience, and the experience of people I have worked with, the AHJ does not have to accept anything, they are in complete control, they don't have to justify why they are rejecting something. This is both good and bad. It's good because the AHJ is not bound by law to apply the NEC to installations and can allow methods and materials to be used that would not be NEC compliant as long as they accept it. It's bad because sometimes an AHJ's decision seems to defy logic and the wording of the NEC and we have to do something we do not believe is needed just because the AHJ says so.