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Discussion Starter · #1 ·
The way I read this is what I'd call a "Class 320" CSED, e.g. a "400 Amp" Panel with 2x 200 Amp breakers
would no longer be OK as it doesn't meet the conditions listed. These are common, e.g. Square D
CU816D400CB or SU3040D400CBs which are commonly installed for residences here.

Do I have this wrong? They don't seem to be:
(1) Separate enclosures...
(2) Panelboards with a main service disconnecting means in each enclosure
(3) Switchboards where there is only one service disconnect means in each
separate vertical section.
(4) Service disconnects in switchgear or metering center where each disconnect is located
in a separate compartment.

Maybe 3 is met since the second main doesn't have a vertical section, but that doesn't
seem to be the intent.

So are these panels illegal under 2020? We're still on 2017, but planning for the future....

I must be missing something.
 

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It is perfectly legal to have a panel with two to six mains; they just can't be service disconnects. I don't know about lobbyists, but I do know lots and lots of sparkies have hit live bus working in split-bus panels. In subpanels, well, you had the option to kill the feeder upstream. In service panels . . . that's part of how we got this rule. I like using MB panels as subs; just have to float the neutral and separate any wire grounds.
 

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Discussion Starter · #4 ·
It is perfectly legal to have a panel with two to six mains; they just can't be service disconnects. I don't know about lobbyists, but I do know lots and lots of sparkies have hit live bus working in split-bus panels. In subpanels, well, you had the option to kill the feeder upstream. In service panels . . . that's part of how we got this rule. I like using MB panels as subs; just have to float the neutral and separate any wire grounds.
There is no definition of "service disconnect" in Article 100, but 230.70 General says: "Means shall be provided to disconnect all ungrounded conductors in a building
from the service conductors." Maybe I misunderstand what is meant by "service disconnect" since it's not defined, but since this is what the "mains" in the panels
I am talking about do, it's my understanding that they are "service disconnects." If so, these very common panels would appear to be illegal under the 2020 NEC,
unless a separate disconnect were provided on the service side of the meter, which seems awkward.

I hope I'm misinterpreting this.
 

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I agree with your Code interpretation, Rex. Under the 2020 NEC these very common panels, that used to be used for service panels, meaning panels that include the first service disconnects, will be illegal when installed for that purpose (as opposed to being installed as subpanels). They're still Listed panels, and still have legit uses, but the installations you're talking about will earn red tags.

Just to underscore a point you made, you can use them as distribution panels if you install a service switch outside, and that incidentally can also satisfy 230.85 as a firefighter's disconnect. HOWEVER, even if that outside switch is rated for service duty, if the firefighter's switch is not marked as the service disconnect and/or you ground the neutral of its load cable, then that would be a service cable, not a feeder, and this panel mounted inside would be serving as the service. This use would be illegal under the 2020 NEC, barring local amendments. In my teddibly 'umble opinion.
 
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