Mismatching MMCB Breaker and Enclosure Manufacturers

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cottora

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Atlanta, GA
I think I know the answer - the enclosure specifies "for use with". So I think using a breaker that is not listed as "for use" will not work.

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LarryFine

LarryFine

Master Electrician Electric Contractor Richmond VA
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The concern isn't matching manufacturers, per se, but approved breaker type in the panel's listing.

If a given Square D breaker model is acceptable per the GE panel labeling, it's allowed to be used.

BR breakers, for example, have been manufactured by more than one company over the years.
 
don_resqcapt19

don_resqcapt19

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The enclosure is not the issue...the connection between the bus and the breaker is the issue.
You either use a breaker that is specified by the panel manufacturer for that panel bus, or you use a different brand breaker that that has been "classified" for use with that panel bus.
 
don_resqcapt19

don_resqcapt19

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wwhitney said:
When that connection is 2 or 3 bolts, if the spacing matches, is there plausibly a functional issue, or is it just a listing issue (it will work but it hasn't been tested)?

Cheers, Wayne
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Most likely just a listing and/or approval issue....but those can be a real issue when there is some type of incident that ends up involving lawyers :D
 
dkidd

dkidd

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don_resqcapt19 said:
The enclosure is not the issue...the connection between the bus and the breaker is the issue.
You either use a breaker that is specified by the panel manufacturer for that panel bus, or you use a different brand breaker that that has been "classified" for use with that panel bus.
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OP didn't say that there was a panel(board) or bus involved, just an enclosure
 
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cottora

Senior Member
Location
Atlanta, GA
oldsparky52 said:
I agree, it sounds like maybe he's wanting to replace an enclosed 400-amp breaker. Doesn't want to switch enclosures, can't get the GE but can the SQ D.
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This is correct. We actually want to use a UL-listed Susol 400A MCCB, but we cannot source a listed enclosure made for it.
 
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jap

Senior Member
Occupation
Electrician
cottora said:
I can run that idea to ground. The 400A breaker is also the disconnect. Can a service disconnect be inside of a cabinet/box?
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Doubt it.

I would think a service disconnect would have to have a way to be externally operable.

JAP>
 
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jap

Senior Member
Occupation
Electrician
electrofelon said:
Code reference?

On another note there is 230.66 that requires service equipment be marked to identify as being suitable for you to service equipment. That may be a deal breaker for a DIY service disconnect enclosure.
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Used to be this:


1637698534135.png

JAP>
 
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jap

Senior Member
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We've been shot down before because of the door on a MLO panelboard with a single large breaker in in attempts to reduce the cost of a larger 3r ECB fo this very reason of it not being externally operable.

Right or wrong it just stuck with me.

May not be the case by actual the rule of the NEC.

Never had a reason to question it.

JAP>
 
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jim dungar

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jap said:
We've been shot down before because of the door on a MLO panelboard with a single large breaker in in attempts to reduce the cost of a larger 3r ECB fo this very reason of it not being externally operable.

Right or wrong it just stuck with me.

May not be the case by actual the rule of the NEC.

Never had a reason to question it.

JAP>
Click to expand...
Pull out style switches are typically not externally operable, nor are most meter mains.
Manufactures sell 'flat front' 3R enclosure for circuit breakers.
 
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