# explain 225.33(A)



## RIVETER (Sep 26, 2009)

Do you suppose you can use a split buss panel?


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## uber stein (Aug 20, 2010)

Had to google what a split buss panel was. Am just being curious, hence trying to understand 225.33, *if* my assumption was correct as the code can be a pain to decipher


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## Magnettica (Jan 23, 2007)

uber stein said:


> My understanding of this is any single detached building one feeder or branch circuit is allowed with 6 disconnects. So basically if i have a detached garage or shed and have a sub panel the most breakers i can have in sub is 6 circuits. What if more than 6 is needed? Or can i have a main breaker in sub and have more than 6 disconnects/breakers?


Even if you have less than 6 circuit breakers you still need a means of disconnect at the detached garage if they are feeders. Don't forget 250.32 and the ground rod while you're at it. 230.70


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## RIVETER (Sep 26, 2009)

uber stein said:


> Had to google what a split buss panel was. Am just being curious, hence trying to understand 225.33, *if* my assumption was correct as the code can be a pain to decipher


Your question is actually a great question. The code says a lot of things but maybe someone can tell why the writers made that ruling.


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## uber stein (Aug 20, 2010)

250.32 exception says no ground rod if supplied by a single circuit and includes an EGC, hence the 4th wire, or am i misreading that?


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## Magnettica (Jan 23, 2007)

uber stein said:


> 250.32 exception says no ground rod if supplied by a single circuit and includes an EGC, hence the 4th wire, or am i misreading that?


That rule applies for branch circuits only.


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## uber stein (Aug 20, 2010)

How can it only apply to branch circuits only? When 250.32(A) states :

Building(s) or structures supplied by *feeders* or *branch circuits* shall have an grounding electrode, etc..

Exception: A grounding electrode shall not be required where only a single branch circuit, *including a multiwire branch circuit*, *supplies* the building or structure and the branch circuit includes an EGC, etc..

Not trying to be argumentative but want to understand, and appreciate all the help i can get.. no help at work, they are stuck in stone ages


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## RIVETER (Sep 26, 2009)

uber stein said:


> How can it only apply to branch circuits only? When 250.32(A) states :
> 
> Building(s) or structures supplied by *feeders* or *branch circuits* shall have an grounding electrode, etc..
> 
> ...


Is what you posted the "08" code. I was thinking about just that yesterday, at least the exception part.


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## uber stein (Aug 20, 2010)

yes.. 08, is only code book i have.. will be getting 11 next year,


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## RIVETER (Sep 26, 2009)

uber stein said:


> yes.. 08, is only code book i have.. will be getting 11 next year,


It should be out in October. I don't quite understand the reasoning of not "having" to drive a ground rod at the structure. Other than a service mast possibly extending in to the air what would be the difference in mandating one at the primary service and not at the branch at the structure? Unless the code writers were just thinking about the OTHER possible aberrant voltages, only. When the code says a rod is not mandated when the wiring to the second structure has an egc, it seems to me that if a strike event occurs at the second structure it could possibly find its way into the panel of the first structure. To me there is no sense in that.


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## uber stein (Aug 20, 2010)

Going to bed, but tomorrow night hopefully i can explore this further on the 6 disconnects.. am still a bit confused. 

With a MLO sub only 6 disconnects/breakers? If MB sub more than 6?


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## ohmdoctor (Oct 5, 2007)

250.32 exception (A) would be say if you had 120 or 220v circuit at the building for a receptacle or two. not an entire panel

If your going to have a panel at that building than it would need a disconnecting means at the building for that panel and the building would need to be grounded to meet 250.32

I think you may have the whole six handles/ breakers confused with the main service of a building/ dwelling if you have Six handles or less at a main service there is an exception that does not require a main disconnect for that service. 230.71(a)


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## TOOL_5150 (Aug 27, 2007)

Nevermind.. found it.

~Matt


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## TOOL_5150 (Aug 27, 2007)

Magnettica said:


> Even if you have less than 6 circuit breakers you still need a means of disconnect at the detached garage if they are feeders. Don't forget 250.32 and the ground rod while you're at it. 230.70


Wrong. 

225.33 Maximum Number of Disconnects.
(A) General. The disconnecting means for each supply
permitted by 225.30 shall consist of not more than six
switches or six circuit breakers mounted in a single enclosure,
in a group of separate enclosures, or in or on a switchboard.
There shall be no more than six disconnects per
supply grouped in any one location.


~Matt


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## jwjrw (Jan 14, 2010)

Magnettica said:


> Even if you have less than 6 circuit breakers you still need a means of disconnect at the detached garage if they are feeders. Don't forget 250.32 and the ground rod while you're at it. 230.70



I missed the part where you said feeders. But the breaker in the panel you are feeding from should be your disconnect for the feeders. 6 or less throws is legal on a detached structure and IS considered the disconnect for the structure.If you will have more than 6 you either have to use a main breaker panel or back feed a main lug panel and use a tie down kit.


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## Dennis Alwon (May 9, 2009)

uber stein said:


> My understanding of this is any single detached building one feeder or branch circuit is allowed with 6 disconnects. So basically if i have a detached garage or shed and have a sub panel the most breakers i can have in sub is 6 circuits. What if more than 6 is needed? Or can i have a main breaker in sub and have more than 6 disconnects/breakers?


First you cannot have a branch circuit with 6 disconnect because that would make the branch circuit a feeder. And yes you can have 6 disconnects or a main disco or breaker with more than 6 branch circuits.

Except allows a single branch cir. , including a MWBC, to be used without any electrodes, however you still would need a disconnect at the separate structure. This could be a DP or SP switch.


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## Bob Badger (Apr 19, 2009)

Dennis Alwon said:


> Except allows a single branch cir. , including a MWBC, to be used without any electrodes, however you still would need a disconnect at the separate structure. This could be a DP or SP switch.


What would prevent you from using up to six single pole switches as the disconnecting means for a single branch circuit? 

Kind of odd but I am not sure it would be wrong.


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## Dennis Alwon (May 9, 2009)

Bob Badger said:


> What would prevent you from using up to six single pole switches as the disconnecting means for a single branch circuit?
> 
> Kind of odd but I am not sure it would be wrong.


You can do that if you want but why would you. That would look like crap and waste a lot of material to gain what exactly? Are you just looking for trouble this morning????


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## Bob Badger (Apr 19, 2009)

Dennis Alwon said:


> You can do that if you want but why would you. That would look like crap and waste a lot of material to gain what exactly? *Are you just looking for trouble this morning????*


No more than usual. :thumbsup:

You had said that you could not use multiple switches I was just pointing out that you can.


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## Dennis Alwon (May 9, 2009)

Bob Badger said:


> You had said that you could not use multiple switches I was just pointing out that you can.


Well you can but then it wouldn't be a feeder as I stated. My point was to correct the op's sentence to establish the difference between a branch circuit and a feeder. 



> My understanding of this is any single detached building one feeder or branch circuit is allowed with 6 disconnects.


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## Magnettica (Jan 23, 2007)

TOOL_5150 said:


> Wrong.
> 
> 225.33 Maximum Number of Disconnects.
> (A) General. The disconnecting means for each supply
> ...


Wrong.

You're still going to need a main disconnect if you run more than a MWBC. 

What are you going to do, run 6 branch circuits through a conduit and hook up single pole switches at the garage door? :laughing:


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## jwjrw (Jan 14, 2010)

Magnettica said:


> Wrong.
> 
> You're still going to need a main disconnect if you run more than a MWBC.
> 
> What are you going to do, run 6 branch circuits through a conduit and hook up single pole switches at the garage door? :laughing:



If you pull a feeder to the garage you can use a main lug with no main disconnect. The 6 throws are your disconnect as long as you have no more than 6 throws. If you have more than 6 throws a main must be added.


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## uber stein (Aug 20, 2010)

Thanks for all who responded and I think I understand it now.. now for the ground rod at the detached building 250.32


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## Dennis Alwon (May 9, 2009)

uber stein said:


> Thanks for all who responded and I think I understand it now.. now for the ground rod at the detached building 250.32


You need two unless you use a MWBC then you don't need any. Under the 2008 code you need a 4 wire feeder where the ground and neutral are separated. The rods will get connected to the EGC bar not the neutral bar.


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## uber stein (Aug 20, 2010)

Dennis Alwon said:


> You need two unless you use a MWBC then you don't need any. Under the 2008 code you need a 4 wire feeder where the ground and neutral are separated. The rods will get connected to the EGC bar not the neutral bar.



After reading 250.32 many times and many more times, i have to agree that ground rods have to be placed at the detached building. Looking back at the sheds I have put a sub in at, it would have been a chore to run a ground wire out to a ground rod. 

And, Yes, there still has to be 4 wires ran even though there will be a ground rod, to bond the grounding system


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## John Valdes (May 17, 2007)

Magnettica said:


> Wrong.
> 
> You're still going to need a main disconnect if you run more than a MWBC.


Still Wrong.
A sub panel in a detached structure with six or less breakers requires no main disconnect. You could even use a 42 space MLO panel and not use a disconnect.
Now, this makes no sense and I would not use this rule period. I would use a main breaker panel in every case. Inspectors cannot inspect for future additions (breakers) in this case, they can only inspect what is installed now and is under inspection. So six breakers in a 42 space panel requires no disconnecting means. 

On the other hand a branch circuit or MWBC does require a disconnecting means. And both require ground rod or rods.


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## Dennis Alwon (May 9, 2009)

John Valdes said:


> On the other hand a branch circuit or MWBC does require a disconnecting means. And both require ground rod or rods.


John I have to disagree with you on this. Look at the exception to 250.32(A)


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## TOOL_5150 (Aug 27, 2007)

Magnettica said:


> Wrong.
> 
> You're still going to need a main disconnect if you run more than a MWBC.
> 
> What are you going to do, run 6 branch circuits through a conduit and hook up single pole switches at the garage door? :laughing:


Prove me wrong, seriously. The way I read it, you can have up to 6 disconnects.

I have run 4 circuits to a detached structure, and used 4 toggle switches as disconnects. It passed inspection.

~Matt


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## TOOL_5150 (Aug 27, 2007)

John Valdes said:


> On the other hand a branch circuit or MWBC ......... And both require ground rod or rods.


2005 NEC 250.32 exception. NO rods needed.

~Matt


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## Jlarson (Jun 28, 2009)

I got to go with Matt here. I read it to say six handles or less no main needed, and that is how I have done a lot of detached structures, with a 60 amp feeder and a 6 space MLO panel no main involved.


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## Funkyjunk (Sep 29, 2010)

uber stein said:


> My understanding of this is any single detached building one feeder or branch circuit is allowed with 6 disconnects. So basically if i have a detached garage or shed and have a sub panel the most breakers i can have in sub is 6 circuits. What if more than 6 is needed? Or can i have a main breaker in sub and have more than 6 disconnects/breakers?


The permitted number of circuits FEEDING the second building is 6 and that is ONLY if the building falls under the special conditions 225.30 A thru E. 

Most people would run 1 feeder if they are doing 1 sub panel. It does not say that the sub panel can only have 6 circuits.

Thats how I read it. Make more sense?


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## jwjrw (Jan 14, 2010)

Funkyjunk said:


> The permitted number of circuits FEEDING the second building is 6 and that is ONLY if the building falls under the special conditions 225.30 A thru E.
> 
> Most people would run 1 feeder if they are doing 1 sub panel. It does not say that the sub panel can only have 6 circuits.
> 
> Thats how I read it. Make more sense?




You could pull a mwbc and have no panel.......just a sp switch as a disconnect....
You could pull your feeder to a main lug panel. As long as you had no more than 6 breakers no main is needed. But if you have more than 6 circuits you need a main.


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## McClary’s Electrical (Feb 21, 2009)

Funkyjunk said:


> The permitted number of circuits FEEDING the second building is 6 and that is ONLY if the building falls under the special conditions 225.30 A thru E.
> 
> Most people would run 1 feeder if they are doing 1 sub panel. It does not say that the sub panel can only have 6 circuits.
> 
> Thats how I read it. Make more sense?


 

You're wrong, you can't have 6 circuits feeding one building

Dennis, Matt, and JR have it right


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## Dennis Alwon (May 9, 2009)

mcclary's electrical said:


> You're wrong, you can't have 6 circuits feeding one building


Actually he is right in fact you can have 7 feeders. He did say under special conditions. So you have the original feeder and if you have all the 6 special conditions listed in 225.30(A) then you can have 7. Not very likely. And then you can have more based on b-e


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## Magnettica (Jan 23, 2007)

This is directly from the 2005 Handbook. 

The basic requirement on locating the disconnecting means for a feeder or branch circuit supplying a structure is essentially the same as that specified for services in 230.70(A), but an important difference applies to feeder and branch circuit sources. Unlike a premises supplied by a service, *where a building or structure is supplied by a feeder or branch circuit, there always needs to be a feeder or branch circuit disconnecting means at the building or structure supplied* unless one of the conditions in exceptions 1-4 can be applied. (225.32 exceptions 1-4).


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## Bob Badger (Apr 19, 2009)

Magnettica said:


> This is directly from the 2005 Handbook.
> 
> The basic requirement on locating the disconnecting means for a feeder or branch circuit supplying a structure is essentially the same as that specified for services in 230.70(A), but an important difference applies to feeder and branch circuit sources. Unlike a premises supplied by a service, *where a building or structure is supplied by a feeder or branch circuit, there always needs to be a feeder or branch circuit disconnecting means at the building or structure supplied* unless one of the conditions in exceptions 1-4 can be applied. (225.32 exceptions 1-4).


And that is correct, but that disconcerting means can be up to six breakers in a MLO panel.


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## Magnettica (Jan 23, 2007)

So, not to sound like a wise-ass, but you can't attach a 2 single pole switches to a #6 copper feeder and call it a day. A means to disconnect the feeder (if you have a feeder) has to be there, either inside or outside the structure.


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## Magnettica (Jan 23, 2007)

Bob Badger said:


> And that is correct, but that disconcerting means can be up to six breakers in a MLO panel.


How can it be if we have a 4-wire feeder?


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## McClary’s Electrical (Feb 21, 2009)

Magnettica said:


> How can it be if we have a 4-wire feeder?


 

you lost me there, what does the feeder have to do with the disconnecting means


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## Magnettica (Jan 23, 2007)

mcclary's electrical said:


> you lost me there, what does the feeder have to do with the disconnecting means


where it says, "there always needs to be a feeder or branch circuit disconnecting means at the building".


So how do you disconnect from the feeder without a main breaker?


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## McClary’s Electrical (Feb 21, 2009)

Magnettica said:


> where it says, "there always needs to be a feeder or branch circuit disconnecting means at the building".
> 
> 
> So how do you disconnect from the feeder without a main breaker?


 


with 6 single breakers:whistling2:

this is ele 101 mag, come on


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## Bob Badger (Apr 19, 2009)

Mag, if you were and inspector using only the code book what section would you cite if I install a MLO panel with six or less breakers?


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## Dennis Alwon (May 9, 2009)

Magnettica, try this article for size and see what you think.



> 225.33 Maximum Number of Disconnects.
> (A) General. The disconnecting means for each supply permitted by 225.30 *shall consist of not more than six switches or six circuit breakers mounted in a single enclosure*, in a group of separate enclosures, or in or on a switchboard. There shall be no more than six disconnects per supply grouped in any one location.


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## Magnettica (Jan 23, 2007)

The basic requirement on locating the disconnecting means for a feeder or branch circuit supplying a structure is essentially the same as that specified for services in 230.70(A). 




> VI. Service Equipment — Disconnecting Means
> 230.70 General. Means shall be provided to disconnect all
> conductors in a building or other structure from the serviceentrance
> conductors.
> ...



So are you saying it's ok to install a brand new main panel with only 6 circuits and no main breaker?


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## McClary’s Electrical (Feb 21, 2009)

Magnettica said:


> The basic requirement on locating the disconnecting means for a feeder or branch circuit supplying a structure is essentially the same as that specified for services in 230.70(A).
> 
> 
> 
> ...


 


yes.....


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## Jlarson (Jun 28, 2009)

Magnettica said:


> So are you saying it's ok to install a brand new main panel with only 6 circuits and no main breaker?


:yes: :yes:


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## Dennis Alwon (May 9, 2009)

Magnettica said:


> So are you saying it's ok to install a brand new main panel with only 6 circuits and no main breaker?


Absolutely. That was a common install in this area years ago. They used a WP 12 circuit panel and installed 6 DP breakers-- usually the well pump motor, dryer, range, a/c, heater and sub panel feeder.


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## Bob Badger (Apr 19, 2009)

Magnettica said:


> So are you saying it's ok to install a brand new main panel with only 6 circuits and no main breaker?


Yes, absolutely and we do this very often in commercial work.

We will install a MLO switchgear section that will contain up to 6 breakers.

Say we have a store that needs a 1600 amp 480 volt service. If we install a single 1600 amp main breaker it would have to be a GFP type $$$$$

If we install a 1600 amp MLO panel with say a couple of 800 amp breakers, a couple of 600s and a couple of 400s none of the breakers will have to be GFP.


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## Magnettica (Jan 23, 2007)

Bob Badger said:


> Yes, absolutely and we do this very often in commercial work.
> 
> We will install a MLO switchgear section that will contain up to 6 breakers.
> 
> ...




So no main disconnect whatsoever?


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## Bob Badger (Apr 19, 2009)

Magnettica said:


> So no main disconnect whatsoever?



Nope, just two to six service disconnecting means.

You can even push it to seven if you have a fire pump.


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## Magnettica (Jan 23, 2007)

Well that's good, got everyone in an uproar over some disconnects. :laughing:


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## Jlarson (Jun 28, 2009)

Magnettica said:


> Well that's good, got everyone in an uproar over some disconnects. :laughing:


See what its like to be a troll. :laughing: J/K


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## Magnettica (Jan 23, 2007)

Jlarson said:


> See what its like to be a troll. :laughing: J/K


Next detached garage I do guess what... I'm putting in a main breaker panel.

Honestly, oh nevermind. :no:


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