MCC Breaker Notation

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petersonra said:
that is not my understanding from long chats with the product managers that market these things.

there is often a minimum size enclosure specified as part of the instructions.

I have seen a few that the instructions mention it is for ul508a applications, so they could only be assembled into a UL508a listed panel. But not all of them say that.

if what you are saying is true, only an enclosed starter with the label on it would be over 5kA.

by the way, kaic is a rating for the interrupting device such as the CB or fuse. the assembly has a short circuit current rating measured in kA. There is a big difference.
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Are you also saying that the charts supplied by UL listing the parts that can be assembled together to form an assembly with a specified SCCR are incorrect in some way?

Here is a typical chart from UL. Are you saying this cannot be used? I have charts like this made by UL for all kinds of combinations of parts.

View attachment 3RW SCCR ratings Rec 12_19_12.pdf
 
petersonra said:
Are you also saying that the charts supplied by UL listing the parts that can be assembled together to form an assembly with a specified SCCR are incorrect in some way?

Here is a typical chart from UL. Are you saying this cannot be used? I have charts like this made by UL for all kinds of combinations of parts.

View attachment 8759
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Basically, when putting together a started in a given enclosure it is subjected as an assembly to bunch that are so sever that the manufacture attempts to blow the enclosure appart to assure that if the thing blows itself apart that it contains the damage within the and not blowing the enclosure apart.
Remember that the UL label for the rating of enclosed control is placed on the enclosed itself. As such in you build your own enclosed control how do are you able to obtain that UL label?
 
templdl said:
Basically, when putting together a started in a given enclosure it is subjected as an assembly to bunch that are so sever that the manufacture attempts to blow the enclosure appart to assure that if the thing blows itself apart that it contains the damage within the and not blowing the enclosure apart.
Remember that the UL label for the rating of enclosed control is placed on the enclosed itself. As such in you build your own enclosed control how do are you able to obtain that UL label?
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You keep saying this. But no where in any of the documentation I have from the manufacturers or from UL does it say this.

It is true for an untested combination of parts, but my understanding is that its not true for a combination of parts UL has tested together.

take a look at a typical Type F starter that has a 65kA SCCR. They are not even in an enclosure. Are you claiming they are not 65 kA even though both the UL and manufacturer's literature says they are?
 
petersonra said:
You keep saying this. But no where in any of the documentation I have from the manufacturers or from UL does it say this.

It is true for an untested combination of parts, but my understanding is that its not true for a combination of parts UL has tested together.

take a look at a typical Type F starter that has a 65kA SCCR. They are not even in an enclosure. Are you claiming they are not 65 kA even though both the UL and manufacturer's literature says they are?
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There's a difference between SCCR which some us may refer to as "with stand"and "interrupting rating." How does one achieve a UL listing on a combination starter. Should there be a massive fault how do you know that the parts and pieces can be kept within the enclosure? We may be referring to two different things, the way components are listed and rated verses components put together in an assembly and that assembly tested as such in an enclosure and UL listed with the UL planet affixed to the enclosure.
A component that has an SCCR doesn't imply that it has an interrupting rating. It is extremely important the the device is not subject to a fault that is greater than its SCCR. As such that is why it is so important for it to be tested the an OCPD that has the ability to assure that the SCCR is not exceeded. Is a contactor have the ability to withstand a fault? Likewise, can an OLR withstand a fault?
That's the importance of combination testing with either fuses or breakers. Even the wiring as well as the components them selves introduce impedance to the circuit which can assist in the further reduction of fault current.
This is what I'm getting at which may not be even in the same ballpark as you may be thinking of.
 
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