6 disconnect rule violation?

[George Stolz]

Re: 6 disconnect rule violation?

Originally posted by jwelectric:
A real close reading of 408.36 will find an exception;

No reading things closely - the thread will die.

Exception No. 1: Individual protection for a lighting and appliance panelboard shall not be required if the panelboard feeder has overcurrent protection not greater than the rating of the panelboard.

This exception is knocked down by the rule found in 225.31 and 32 which states that the separate building is required to have a disconnecting means either inside or outside.

I think you're confusing "overcurrent protection" and "disconnecting means", Mike. Nothing gets knocked down, I think these two codes work hand in hand.

The feeder protecting the panelboard to a detached structure is necessarily going to have overcurrent protection, agreed?

I'm not saying that this remote OCPD acts as the disconnecting means at the remote structure, it's acting as the overcurrent protection. The feeder is protected, as is the panelboard. So 408.36(A) is satisfied when you're talking about a 225-governed installation.

408.36(A) makes no comment about where the overcurrent protection is, it doesn't care.

So:

If a lighting & appliance panelboard is to be used for service equipment, then 408.36(A) states that it does need a main, and that is reinforced by Exception No 2, which states that existing installations used as service equipment can sit as they are, without individual protection.

If a lighting & appliance panelboard is to be used for a (225-governed) detached building, the one-line would be as follows:

Service >
Main Breaker >
Main Feeder >
Main Panel >
Feeder OCPD >
Underground Feeder Cable (UF/ URD) >
L&A-BC-PB enclosure >
Up to 6 handles, or main over that >
Branch circuits

A detached building would be able to use any size MLO panel, provided:
</font>

• <font size="2" face="Verdana, Helvetica, sans-serif">225.32, It's outside, give or take</font>
• <font size="2" face="Verdana, Helvetica, sans-serif">225.33(A), There are not more than 6 handles,</font>
• <font size="2" face="Verdana, Helvetica, sans-serif">225.36, it's marked as suitable for use as service equipment</font>
• <font size="2" face="Verdana, Helvetica, sans-serif">225.39(A)(B)(D), the one handle is rated 15, the two handles add up to 30, or all of them add up to 60.</font>
• <font size="2" face="Verdana, Helvetica, sans-serif">225.40, the feeder OCPD from the originating building is readily accessible or the crutches offered are used.</font>

<font size="2" face="Verdana, Helvetica, sans-serif">
Whadya think?

 

[jwelectric]

Re: 6 disconnect rule violation?

George I agree with every thing that you said.

Now if the remote panel has more than ten percent of its over current devices protecting lighting and appliance circuits then this panel will need to be protected by not more than two mains as outlined in 408.34 and 408.36.

The fact that I have a panel with six single pole fifteen, twenty or thirty amp breakers protecting six circuits does not relieve the requirement of a main, it mandates the main.

 

[George Stolz]

Re: 6 disconnect rule violation?

Originally posted by bphgravity:
I guess it comes down to whether you think (or the AHJ thinks) the language in 230.80 has been intentionally left out of Article 225 or if the ommission is by mistake.

How about this for some food for thought on this portion of the topic. The following is purely speculative, conversational, and throwing it out there for discussion. It's a concept invented by me, off the cuff, to account for this oddity in the code. With that disclaimer:

For all practical purposes, a service "rating" is only as good as the conductors supplying it. The NESC will govern many of these conductors, so the NEC basing a rating on the supplying conductors would be kinda tenuous.

So perhaps the solution was to numbly add up the handles, since the handles would be supplying loads in accordance other sections of the NEC and would be safe.

Once they got around to writing 225, they knew the NEC would be governing the conductors supplying the disconnecting means at a detached structure. So perhaps the detached structure's rating should be in accordance with the rating of the OCPD supplying the feeder.

Thoughts?

 

[George Stolz]

Re: 6 disconnect rule violation?

Originally posted by jwelectric:
George I agree with every thing that you said.

I get all excited, and then...

...this panel will need to be protected by not more than two mains as outlined in 408.34 and 408.36.

There is overcurrent protection at the originating structure, Mike. 408.36(A) is satisfied without a single breaker in the panel at the remote structure.

The fact that I have a panel with six single pole fifteen, twenty or thirty amp breakers protecting six circuits does not relieve the requirement of a main...

No, those breakers have nothing to do with it.

The breaker at the originating house does.

I think I figured it out.

 

[jwelectric]

Re: 6 disconnect rule violation?

Originally posted by georgestolz:


So perhaps the solution was to numbly add up the handles, since the handles would be supplying loads in accordance other sections of the NEC and would be safe.

Thoughts?

Let?s look at this handle tying that is being talked about so much in this remote panel.

225.33 (B) Single-Pole Units. Two or three single-pole switches or breakers capable of individual operation shall be permitted on multiwire circuits, one pole for each ungrounded conductor, as one multipole disconnect, provided they are equipped with handle ties or a master handle to disconnect all ungrounded conductors with no more than six operations of the hand.

As is stated in 225.33(B) just any two or three breakers can not be tied together. They must be on a multiwire circuit.

 

[George Stolz]

Re: 6 disconnect rule violation?

Mike, Bryan and I discussed in this thread and the last one: How does one determine the "rating" of a disconnecting means?

Bryan believes there needs to be a 60 amp breaker to comply with a non-dwelling structure with more than two circuits.

I believe that, well, I don't know what to believe.

To me, the rating of the OCPD supplying the structure is the logical choice to determine the "rating."

See the second or third page of this thread for the links to the other threads, you'll see what we were discussing and the various viewpoints.

 

[jwelectric]

Re: 6 disconnect rule violation?

I fail to see where there is any difficulty in the rating of the disconnecting means. Let me explain.

If I decide to use a knife disconnect as the disconnecting means at the remote building then this would be an easy answer as they only sell them at the following ratings: 30, 60. 100, 200 ect?..
If I decide to use a breaker as the disconnecting means the rating of the breaker will be right on the handle.

Where is the problem in the rating of the disconnection means?

 

[russ]

Re: 6 disconnect rule violation?

I agree with Bryan thinking that a 60 amp main is what the code is calling for.

With that said, I'm sure when this was debated by the code panel, average home garages probably were not the main purpose of the article.

I think this would be a good time to use 90.4 to allow this installation rather than reject it.

 

[George Stolz]

Re: 6 disconnect rule violation?

Originally posted by jwelectric:
Where is the problem in the rating of the disconnection means?

You're allowed up to six handles.

In 230.80, you're asked to add the handles together to get the rating (60 amps).

In 225, you're not given a method.

Bryan believes that each of the six handles must be rated 60 amps. I believe you could technically have 6 handles that total 60 amps, although it's not outlined for 225-governed installations.

I believe the best method would be to look at the OCPD at the originating structure. Given the permanent nature of direct-buried conductors, the conductors in the ground are likely the most permanent feature of the installation, IMO.

 

[George Stolz]

Re: 6 disconnect rule violation?

What about the other issue, what do you think of my answer, Mike?

(...and other members.)

 

[jwelectric]

Re: 6 disconnect rule violation?

Originally posted by georgestolz:
What about the other issue, what do you think of my answer, Mike?

(...and other members.)

 

[jwelectric]

Re: 6 disconnect rule violation?

Originally posted by mdshunk:
Has anyone ever been violated for installing 1 single pole breakers in a 8 circuit MLO panel at a residential accessory structure? (assume breaker had required hold down). I'm having a discussion with an inspector on another site who insists that this would be a 225.33 violation, because the panel has the potential for 8 breakers. I maintain that you can't inspect for the potential for a future violation.

His quote:
"My area with your panel having 8 circuits available would make me react saying you have capacity of more branch circuit breakers calling for more than the 6 sweeps of the hand in replacement of a main breaker and I would call for the main breaker in that detached structure.

Problem is your panel is listed and labeled for more than 6 sweeps of the hand unless all the breakers are double pole breakers. If you have one breaker installed in that panel then you have listing and labeling of more than 6 sweeps of the hand. I am inspecting what is. 8 circuit listed for use installed with one being a single pole breaker potentially exceeding the 6 sweeps of the hand."

That mentality really strikes a nerve with me.

I am quoting the original post again here for ease in addressing his post.

I agree that the inspector is using the wrong train of though for turning down this job although he is correct for rejecting this installation.

You state that this panel has only one single pole breaker. The fact of a breaker tie down would indicate that the single pole breaker was being back fed for a main disconnecting means which I have never seen. I am not sure that a panel is listed for a single pole main.

The fact that this panel has only one single pole breaker means that it has 100% of its overcurrent devices using the grounded neutral conductor. This is a violation of 480.36 and was justly rejected.

 

[George Stolz]

Re: 6 disconnect rule violation?

Mike, it's a given that we are working with a lighting and appliance branch ciruit panelboard. I think we know this, there's been no debate on that one. None. Not a bit. So, moving on...

Originally posted by jwelectric:
Once again I look at 408.34 and .36....the six disconnect rule is mute. A main will be required as these circuits will be lighting and appliance circuits.

What is muting the six-disconnect rule?

 

[jwelectric]

Re: 6 disconnect rule violation?

225.31 Disconnecting Means.
Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure.
225.32 Location.
The disconnecting means shall be installed either inside or outside of the building or structure served or where the conductors pass through the building or structure. The disconnecting means shall be at a readily accessible location nearest the point of entrance of the conductors. For the purposes of this section, the requirements in 230.6 shall be utilized.

These two rules.

408.36 Overcurrent Protection.
(A) Lighting and Appliance Branch-Circuit Panelboard Individually Protected. Each lighting and appliance branch-circuit panelboard shall be individually protected on the supply side by not more than two main circuit breakers or two sets of fuses having a combined rating not greater than that of the panelboard.

This one if more than 10% of the OCPD is 30 amps or less and use the neutral.

The fact that a disconnect is required at the remote building will not allow the over current protection device for feeders to be the main for the panel as you have drawn. If this panel was in the same building then the panel could be protected by the OCPD for the feeders.

It is not in the same building so the breaker in the house is nothing more than protection for the conductors going out to the building. Sorry.

 

[George Stolz]

Re: 6 disconnect rule violation?

Originally posted by jwelectric:
These two rules.
225.31 Disconnecting Means.
225.32 Location.
408.36 Overcurrent Protection.

225.31 - The panel with up to six breakers in it is the disconnecting means, check
225.32 - It's outside already, check.
408.36(A) - There are no more than two circuit breakers, there is one circuit breaker providing overcurrent protection for the panel, check.

The fact that a disconnect is required at the remote building will not allow the over current protection device for feeders to be the main for the panel as you have drawn.

Where does it say that? 408.36 says overcurrent protection shall be provided on the supply side. It is. Nowhere does 408.36 state that the OCPD must reside on the same structure. 408.36(A) is satisfied.

If this panel was in the same building then the panel could be protected by the OCPD for the feeders.

Cite me a reference.

It is not in the same building so the breaker in the house is nothing more than protection for the conductors going out to the building.

Something I feel I need to add: You stated that a regular knife switch or safety switch rated 60 could be used instead of a panel. What would be protecting that switch, and the conductors on the load side of that switch?

Overcurrent protection is not the same as a disconnecting means.

edit grammar

[ November 27, 2005, 11:59 PM: Message edited by: georgestolz ]

 

[hurk27]

Re: 6 disconnect rule violation?

The fact that this panel has only one single pole breaker means that it has 100% of its overcurrent devices using the grounded neutral conductor. This is a violation of 480.36 and was justly rejected.

480.36?????? did you mean 408.16?
Not if the feeders are protected with an OCPD that is not over the rating of this panel board. 408.16 exception 1.

Lets look at the differant wording of 255.39(A) and 230.79(A)

225.39(A) One-Circuit Installation. For installations to supply only limited loads of a single branch circuit, the branch circuit disconnecting means shall have a rating of not less than 15 amperes.

Now we are allowed 6 of these in one cabnet or seperate cabnets, Right?

230.79(A) One-Circuit Installation. For installations to supply only limited loads of a single branch circuit, the service disconnecting means shall have a rating of not less than 15 amperes.

A 15 amp service disconnect? is the breaker protecting the branch circuit and the service disconnect one in the same?
What reason would there be any benifit to protecting any circuit with two breakers in series that have the same rating?

And as far as 408.16 goes, Why do they state not more than two main circuit breakers??? why would we have two main breakers???? And if we did does this make any sense?
"having a combined rating not greater than that of the panelboard"
How if you added the breakers could you keep them under the rating of the panel?
100 amp panel with what two 50 amp breakers feeding it? or a 60 and a 40? In series?
Would it not make more sense if they were talking about two breakers installed to serve two circuits, then at least the statment "having a combined rating not greater than that of the panelboard" would at least make sense?

Why is it important that a lighting and branch circuit panelboard be protected and a power panelboard not? Both are used in dwelings
both have the same risk's.
And the power panel board if anything has more of a chance of being over loaded because of only line to line loads which will mean higher amperage circuits most of the time?

I think there are some errors here that have been jumbled around over the years and nobody has or wanted to take the time to sort them out.

I would like to look at or access the risk of each type of installation that has been disscussed that don't seem to meet the NEC requirments and ask this simple question, what is the danger with it?

Maybe I'll start a new thread titled NEC errors.

 

[George Stolz]

Re: 6 disconnect rule violation?

Originally posted by hurk27:

This is a violation of 480.36 and was justly rejected.

480.36?????? did you mean 408.16?

2005 change, Wayne. Now it's 408.36.

Man, and I thought the picture would sway Mike.

 

[jwelectric]

Re: 6 disconnect rule violation?

Slow down a little George and look at what has been posted over these pages and reread the articles pointed out.

I will try once again:

225.31 requires a disconnect. 225.39 requires it to be rated per the installation.

Now lets try to remember that an overcurrent device when a breaker can also be the disconnect.

Now let?s put it all together and use the original post as we work through this.

A breaker is installed to protect feeders going to a detached building. This building is required to have a disconnect rated for the installation located at the building.
Knowing this much tells us that exception one of 408.36(A) can not be applied for the disconnect at this detached building.
We are required to install a disconnect at this remote location regardless of what is located inside the house.

So how is this requirement achieved? Simple answer is found in 408.36(A).
The requirement found in 225.39 makes it very clear that we can either install a disconnect and then feed the panel or we can install a panel with a disconnect already in it.

What we can?t do is install handle ties over two or three single pole breakers and call this one disconnect. This panel will require a main as outlined in 408.36(A) or a disconnecting means as outlined in 225.39.

Another way to look at this using your train of though is;

Originally posted by georgestolz
In 230.80, you're asked to add the handles together to get the rating (60 amps).

In 225, you're not given a method.

Bryan believes that each of the six handles must be rated 60 amps. I believe you could technically have 6 handles that total 60 amps, although it's not outlined for 225-governed installations.

Let?s say that I have 12 15 amp breakers with handle ties on two breakers giving me a total of six disconnecting means. Would I now have a disconnect rated at 180 amps or 90 amps? Would I be required to install #3 feeders and a 100 amp breaker at the house or a 3/0 and a 200 amp breaker?

This is so simple that a child could do it. The choices are to install a disconnect or a main breaker panel. Which would be the most cost effective?




Edited for corrections

[ November 28, 2005, 01:49 AM: Message edited by: jwelectric ]

 

[jwelectric]

Re: 6 disconnect rule violation?

Originally posted by hurk27
And as far as 408.16 goes, Why do they state not more than two main circuit breakers??? why would we have two main breakers???? And if we did does this make any sense?

To allow one of these

 

[hurk27]

Re: 6 disconnect rule violation?

Mike
I think you getting requirements a little mixed up here.
408.36 only requires overcurrent protection of a lighting and branch circuit panelboard, it does not require a disconnect, when the overcurrent protection exception #1 to 408.36 has been met it's done.
1. 225.31 only requires a disconnect for "conductors" that supply or pass through a building. the disconnect is not there for the feeders, as they are allowed to enter the building to the disconnect 225.32.
the busbars in a panel become another link in the feeders when 225.33 is used. since the busbars (panel) have overcurrent protection as required by 408.36 exception #1 we have not hit the disconnect yet. we are allowed 6 disconnects as per 225.33,
each of these disconnects only have to be rated for the circuit conductor for which they supply current to. If a 15 amp fuse will limit the amount of current that it will ever see to just 15 amps then 225.39 has been satisfied because it has a "rating for the load to be carried"

would a breaker would not be allowed in a panel that has its busbars protected by a 200 amp breaker? I think not. nether would a 15 amp breaker in a panel protected by a 60 amp or 100 amp circuit.
225.39 is only to make sure the disconnect can handle the load that might be imposed on it. another words you cant use a 60 amp rated panel on 100 amp feeders and put 6 20 amp breakers in it, with a 16 amp load on each circuit, as they would exceed the rating of the panel, If this was a power panel you could very easily do this,

Any switch when used used as a disconnect only has to be at least the rating of the load it will see and can be more. overcurrent protection is the opposite, it can not be more that the rating of what it protects but can be less in some circumstances.