switch gear main

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actually it is regarding gear that was specked on a job I have. 120/208 400 amp there are two 200 amp pull out discos, but I was curious why there would not be a disco for the 400amp gear itself. Aswitch or 400 main for instance. Are you saying that it would only be required if there were more than six loads?
 
A lot of variables.
If you are talking service switchgear, you are allowed to have up to 6 disconnecting means.

If a panel, other than service, has a main ahead of it then you can have an unlimited number of branch circuits in the subpanel with no main (within the panel)
 
230.71 Maximum Number of Disconnects.
(A) General. The service disconnecting means for each service
permitted by 230.2, or for each set of service-entrance
conductors permitted by 230.40, Exception No. 1, 3, 4, or 5,
shall consist of not more than six switches or sets of circuit
breakers, or a combination of not more than six switches and
sets of circuit breakers, mounted in a single enclosure, in a
group of separate enclosures, or in or on a switchboard. There
shall be not more than six sets of disconnects per service
grouped in any one location.
 
A lot of times, it is to get around the ground fault rule by dividing up the load, also it can save from having to buy a main, then smaller breakers, say, you have a 1200 amp service with 3-400 amp panels feed from this service, you can eliminate the 1200 amp main and just use 3-400 amp breakers that you have to buy anyway as a major cost savings.
 
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