main distribution panel

[Scott K]

I'm being told by my supplier that a 400 mdp with 4 breakers (Main disconnects) and provisions for 4 more requires a single main disconnect in it as well because more breakers could be added later to exceed the 6 main disconnect rule. I can't find anything in the nec that supports this. Does anyone know the article number where I can find it? Thanks in advance!

 

[kwired]

I'm being told by my supplier that a 400 mdp with 4 breakers (Main disconnects) and provisions for 4 more requires a single main disconnect in it as well because more breakers could be added later to exceed the 6 main disconnect rule. I can't find anything in the nec that supports this. Does anyone know the article number where I can find it? Thanks in advance!

No such rule in NEC.

Done this with I-line panels before - no way to limit how many breakers can be installed - you had a 400 amp panel but say it were larger and you had combinations of 600, 400 and 225 amp frame sized breakers in it. Each of those takes up a different amount of space in the panel, plus if you should install a single or double pole that also adds to the handle count but takes up different amount of space as well.

It is the person that installs the seventh handle that has violated code.

 

[Jraef]

I'm being told by my supplier that a 400 mdp with 4 breakers (Main disconnects) and provisions for 4 more requires a single main disconnect in it as well because more breakers could be added later to exceed the 6 main disconnect rule. I can't find anything in the nec that supports this. Does anyone know the article number where I can find it? Thanks in advance!

You can't find the "6 hand rule" because that's not what the NEC says, it's (as per usual) a lot more wordy...

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 or in switchgear. There shall be not more than
six sets of disconnects per service grouped in anyone location..

So if you had a panel with 8 "main" breakers in it, you have violated the rule. But just having SPACES for 2 additional breakers in it does not in itself constitute a violation until those spaces get filled with breakers. You can buy a 42 circuit panel and only put in 6 breakers as mains, still not a violation until the 7th breaker goes in.

 

[kwired]

You can buy a 42 circuit panel and only put in 6 breakers as mains, still not a violation until the 7th breaker goes in.

That said most of your "loadcenters" are not rated for use as service equipment unless there is a single main breaker installed and the supply lands on it. Other panelboards - read the instructions.

I line's I mentioned earlier - the one's I have installed did state they were suitable for use as service equipment when no more then six breakers are installed or something to that effect, though depending on what breakers you did install you may be able to get more then six in there.

Like I said 250 amp and smaller frame size takes less mounting space then 400 and 600 amp frame sizes breakers.

 

[Jraef]

Good point on the SUSE listing issue.