Panel UL Listed for 400 HZ

[charlie b]

We have an AHJ insisting that branch circuit panelboards used to distribute 400 HZ power must be "UL listed for 400 HZ." I do not even know if there is such a listing. Nor do I know if the ability to function at 400 HZ is included in the standard listing for panelboards. Has anyone encountered this requirement?

In a short review of the UL web site, we found that the Table of Contents for UL 489 (circuit breakers) includes a paragraph related to 400 HZ. We did not find a similar paragraph in the Table of Contents for UL 67 (panelboards). Before we spend $800 to buy a UL standard that may or may not give us a basis for responding to the AHJ, does anyone know whether these (or other) UL documents discusses a 400 HZ rating?

 

[augie47]

this probably is not what you want, but I have a UL publication (200-66) entitled "Marking Guide-Panelboards" In Pg 5 it states: ..."UL requires basic electrical rating markings.....the information includes the number of pahses, if other than single phase, and the frequency, if other than 50 or 60 hZ."

I have not found that wording in the White Book.

 

[kc8dxx]

I suggest spending 5 minutes and calling UL, to see if you can find someone who can guide you to a standard. Start with the people who support UL508A. You're willing to spend the $$ on the standard, but not the wrong one. I can't locate anything on the subject in my copy of UL508A, but maybe the question has been asked before and the UL guys who maintain the document know the answer.

 

[jim dungar]

Have you contacted any manufacturer? I know that Square D has application guides on how to apply their breakers on 400Hz systems.

And according to their FAQ website
Question: Are I Line and NF panelboards rated for use at 400Hz
Answer: I line panelboard and NF Panelboards are rated for use at 400hz

 

[roger]

Have you contacted any manufacturer? I know that Square D has application guides on how to apply their breakers on 400Hz systems.

And according to their FAQ website
Question: Are I Line and NF panelboards rated for use at 400Hz
Answer: I line panelboard and NF Panelboards are rated for use at 400hz

In the past when I have been involved with 400HZ projects I have done just that with both SQ D and C-H, they were both very helpful in recommending what we would need.

Roger

 

[petersonra]

Have you contacted any manufacturer? I know that Square D has application guides on how to apply their breakers on 400Hz systems.

And according to their FAQ website
Question: Are I Line and NF panelboards rated for use at 400Hz
Answer: I line panelboard and NF Panelboards are rated for use at 400hz

I was about to suggest the same thing.

Siemens also has a lot of good information on using their stuff at other than 50/60 Hz.

One thing that may be a issue is that the SC rating is much lower at 400 Hz than at 50/60 Hz.