- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Does the NEC define a 'listed combination motor controller' or are you just using the UL guide number for an actual 'Combination Starter'?
motor rated breakers
- Thread starter LMartin57
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Does the NEC define a 'listed combination motor controller' or are you just using the UL guide number for an actual 'Combination Starter'?
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
I think you are obsessing over just what entails being "listed".
UL lists all kinds of combinations of things that do not have a UL listing sticker on the assembly that is specific to the assembly.
Look at MCCBs. They come with the same UL label regardless of whether you get it with the lugs or not. The lugs that come with the CBs are not listed. They are only recognized. The listing includes the various combinations of lugs and MCCB that are allowed. In fact, if you want, you can use your own UL listed lugs and not use the manufacturer's lugs at all.
By the way, I think you need to look at just what constitutes a "combination motor controller". UL has more than one category code that covers combination motor controllers.
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- Location
- Illinois
- Occupation
- retired electrician
As far as I know the NEC does not define that term, but the title of the UL Guide I referenced is the same term as used in the code.
- Location
- Illinois
- Occupation
- retired electrician
That would be fine, but the code very clearly requires that the instantaneous trip breaker be a part of a listed combination motor controller. If the product is not listed as such, you have to use fuses or thermal magnetic breaker.
- Location
- Illinois
- Occupation
- retired electrician
It would be my opinion that the combination motor controller must have the OCPD, the controller, and the overloads and that these items have to listed as a combination. You just can't grab listed or recognized devices and throw them together and say you have a listed combination motor controller.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
I agree with that. UL provides the list of what parts can be assembled together.
i do not believe there is any requirement that they be supplied assembled by the manufacturer or be supplied in an enclosure of some sort.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
In general the list is usually part of the MCP requirements. It is rare to find mechanical starter and overloads which have restrictions on their protective devices, although electronic devices such as VFDs and Soft Starters usually have very specific protection requirements.
- Location
- Illinois
- Occupation
- retired electrician
There is not, and that is why I posted the guide information. It says that it may be assembled from individual discrete components. It also says that is can be an "open" assembly for factory or field installation in an enclosure for industrial control equipment, a cabinet or a cutout box.
I found this Data Bulletin from SqD which includes a UL508 Part IV which defines the component functions, constuction, testing, and performance requirements of 6 styles of combination starters.
There are A, B, C, and combination starter types, and E and F "Recognized" combination starter types.
REFERENCES UL 508
ISBN 0-7629-0404-6
Industrial Control Equipment
Seventeenth Edition, Dated January 28, 1999
NEC
2002 Edition
I believe that you will find the coordination considerations an interesting read. It may be something that would be useful if kept on file.
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