retrofit CT's

[lbartsch]

One of our customers has requested that we retrofit CT's into more than 200 subpanels so they can monitor the load on the branch circuits. Although there appear to be kits (CT's & circuit cards) available from the panel manufacturer and third party vendors, I'm concerned about violating the NEC code by taking up additional gutter space. There is also the listing issue to contend with (I'll address that in the UL forum).

If we add CT's to subpanels, does it impact the gutter calc for conductors?

 

[lbartsch]

retrofit CT's

One of our customers has requested that we retrofit CT's into more than 200 subpanels so they can monitor the load on the branch circuits. Although there appear to be kits (CT's & circuit cards) available from the panel manufacturer and third party vendors, I'm concerned about violating the UL listing by modifying the panel.

If we add CT's to subpanels made by the same manufacturer, is the listing ok?
What if we buy third party CT's?

The way I see it, the panel manufactuer can void the listing either way...

(I've posted a similar message in the NEC forum regarding gutter space violations)

 

[iwire]

I merged the two threads, it only gets confusing having simultaneous threads.

It will be up to the AHJ to decide if what your doing affects the listing.

We do this all the time, I can't imagine any inspector having an issue with this.

 

[lbartsch]

retro CT's

retro CT's

Thanks Bob

I would think that if the CT assembly is designed as a viable part of the panel when listed, there shoud be no issue. A GE subassmebly designed for a GE panel seems straight forward. Its the 3rd party vendor stuff that has me questioning this.

Putting manufacturer A's assembly in maunfacturer B's panel seems a bit problematic. Yet, these kits are out there.

 

[iwire]

Putting manufacturer A's assembly in maunfacturer B's panel seems a bit problematic. Yet, these kits are out there.

I don't see it that way, you put third party parts inside enclosures and cabinets fairly often.

I have posted this a few times recently, it is from the UL white book.

Field Modifications​

What happens to the Listing if a UL-Listed product is modified in the field?

An authorized use of the UL Mark is the manufacturer?s declaration that the product was originally
manufactured in accordance with the applicable requirements when it was shipped from the factory. When
a UL-Listed product is modified after it leaves the factory, UL has no way to determine if the product
continues to comply with the safety requirements used to certify the product without investigating the
modified product. UL can neither indicate that such modifications ??void?? the UL Mark, nor that the
product continues to meet UL?s safety requirements, unless the field modifications have been specifically
investigated by UL. It is the responsibility of the Authority Having Jurisdiction (AHJ) to determine the
acceptability of the modification or if the modifications are significant enough to require one of UL?s Field
Engineering Services staff members to evaluate the modified product. UL can assist the AHJ in making this
determination.

An exception for a field modification authorized by UL is when the product has specific replacement
markings. For example, a switchboard may have specific grounding kits added in the field. The
switchboard is marked with a list of specific kit numbers that have been investigated for use in that
particular switchboard. Only grounding kits that are included on the marking on the product have been
investigated for use in that product.

If a party wishes UL to determine if the modifications made to a UL Listed product comply with UL
requirements, the appropriate Field Engineering Service can be initiated to investigate the modifications.
This investigation will only be conducted after UL consults with the AHJ to ensure that UL?s investigation
addresses all areas of concern and meets all of the AHJ?s needs.

If you have any questions or would like to inquire about a Field Evaluation, contact Field Services at
+1-877-UL-HELPS, prompt #2 (+1-877-854-3577) or visit http://www.ul.com/field/index.html.

It seems "It is the responsibility of the Authority Having Jurisdiction (AHJ) to determine the
acceptability of the modification"

 

[lbartsch]

retrofit

retrofit

Perfect!

This gives me a good place to start. Now to solve the gutter issue...

Thank you