separate strutures disconnects

[stew]

if a separate structure such as a garage is fed with a single branch circuit or a feeder to a subpanel is a disconnect required at the separate stucture or is the disconnecting means in the main building which feeds the stucture sufficient? Or say a pool house ,kennel etc?

 

[electrofelon]

250.32(D). Basically you dont need the disco in the detached structure if an EGC is run with the feeder. Oh and then there is 225.32 ex 1, so the homeowner has to be considered "qualified"

 

[iwire]

IMO you are required to have a disconect at the separate structure.

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 permitted to be utilized.

There are four exceptions to 225.32 which are more or less;

1 Documented safe switching procedures/qualified individuals

2 Industrial wiring systems

3 Light poles

4 Signs


This disconect must also be suitable for use as service equipment.

225.36 Suitable for Service Equipment.

The disconnecting means specified in 225.31 shall be suitable for use as service equipment.

Exception: For garages and outbuildings on residential property, a snap switch or a set of 3-way or 4-way snap switches shall be permitted as the disconnecting means.

 

[jwelectric]

You go Bob

 

[stew]

bob how about 250 (D) does that section not apply? That section tells me that as long as the bonding is done correctly and the egc is separated at the subpaneland an egc is run then the disconnect which is referenced in this section can be remotley located. Your thoughts please

 

[electrofelon]

I could see how one could take thiss either way, but to me the phrases, "Documented safe switching procedures" and "qualified individuals" seem to be addressing more complicated, typically commerciall/industrial installations not a 50 amp panel with seven circuits in a residential garage. Only way to be sure is ask AHJ.

 

[stew]

electro. that phraseology is not part of 252.31 0r 250.32 (D) however as I have read it anyhow. It seems to me to be permitted in (D) and furthermore gives specific instuctions as to how it may be done. the only thing I see here is bobs comment and cite as to being suitable as service equipment which a circuit breaker in a panel is as far as I know

 

[iwire]

Stew 250.32(D) can only be used in conjunction with exceptions 1 and 2 of 225.32 or in other words when you have Documented safe switching procedures/qualified individuals or Industrial wiring systems.

250.32(D) Disconnecting Means Located in Separate Building or Structure on the Same Premises. Where one or more disconnecting means supply one or more additional buildings or structures under single management, and where these disconnecting means are located remote from those buildings or structures in accordance with the provisions of 225.32, Exception Nos. 1 and 2, all of the following conditions shall be met......

That being the case 250.32(D) does not apply to a residential buildings.

Edit spelling

 

[chevyx92]

I agree with Bob. I learned the hard way. I had a installation where this warehouse was to be subfed from another building about 25ft away. I subfed it and set a MLO panel and got written up because I had no means of diconnect on that structure. I argued with the inspector that it was subfed and didn't need it, but he pulled the code out and referenced 225.32 and showed me that I did need a disconnecting means. I had nothing to say after that and had to put a main breaker in the panel.

 

[George Stolz]

...and cite as to being suitable as service equipment which a circuit breaker in a panel is as far as I know

Not exactly. This is a tricky subject - I can't remember the end-all result of a heated discussion we've had on the matter.

Click here for the 24 page debate heard 'round the world. The point I linked to is while the discussion was in progress, but at a pivotal moment.

I believe, if memory serves, the this works is this:

• The panel must be labelled "Suitable for use as service equipment..."
• Likely, after that it says "...when installed in accordance with Article 408 of the NEC." Regardless, it needs to comply with 408.
• It might also say "...when not more than 6 OCPD's are installed and the panel is not used as a lighting and appliance branch circuit panelboard.
• Chances are, the panel in question is usually used as a L&ABCPB.
• However, since there is overcurrent protection ahead of this panel, then it gets a green-light from (2005) 408.36(A) to be the first panel on the structure, since it is protected according to it's rating.
• There is a paradox here if the panelboard is used as a L&ABCPB, because it is suitable as service equipment unless it's used that way. But the only reason that it wouldn't be permitted to be used as service equipment as a L&ABCPB is because there's no overcurrent protection at a service.

It's a good read, recommended.

 

[stew]

bob where do you get the verbage Industrial wiring systems from that article? Also a residence is a structure under single management isnt it? Is ythe homeowner not a qualified individual to know what the safe proceedures are.? I guess not eh?

 

[iwire]

Morning Stew.

bob where do you get the verbage Industrial wiring systems from that article?

Good question, I agree it is not readily apparent.

225.32Exception No. 2: For buildings or other structures qualifying under the provisions of Article 685. the disconnecting means shall be permitted to be located elsewhere on the premises.

ARTICLE 685 Integrated Electrical Systems

I. General

685.1 Scope.

This article covers integrated electrical systems, other than unit equipment, in which orderly shutdown is necessary to ensure safe operation. An integrated electrical system as used in this article is a unitized segment of an industrial wiring system where all of the following conditions are met:

(1)An orderly shutdown is required to minimize personnel hazard and equipment damage.

(2)The conditions of maintenance and supervision ensure that qualified persons service the system.

(3)Effective safeguards, acceptable to the authority having jurisdiction, are established and maintained.

You can see in order to apply 225.32 Exception 2 you must jump through a number of hoops even once you are at an industrial facility.

There is no way I can see a way to use 225.32 Exception 2 at a residence and it looks like it rarely applies in other locations.

Also a residence is a structure under single management isnt it? Is ythe homeowner not a qualified individual to know what the safe proceedures are.? I guess not eh?

I agree that a residence is usually under single management.

However I do not see that a typical homeowner would qualify as a qualified person.

From Article 100.

Qualified Person. One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training on the hazards involved.

In most cases I think it is well beyond a stretch to say a homeowner meets that definition.

Even if we get by that we hit this

where documented safe switching procedures are established and maintained for disconnection,

That requires written policies and procedures IMO this basically means lock out tag out training.

If I was the inspector I would have a hard time accepting that a homeowner will meet the criteria.

and cite as to being suitable as service equipment which a circuit breaker in a panel is as far as I know

The breaker is not the only concern, the panel itself will have to say on the label that it is rated for service equipment, not all panels are listed for use as service equipment.

I have no idea why this is a requirement as the equipment will not be used as service equipment.

Keep in mind the exception to the service rated requirement for residential applications.

A standard single pole switch can be the service disconect for a residential outbuilding as long as you remember to locate it in the correct location "The disconnecting means shall be at a readily accessible location nearest the point of entrance of the conductors".

If we stop and think about it nearly every type of electrical installation requires a local means of disconnection.

Bob

 

[allenwayne]

I have scenario which I thought I dealt with this weekend.At least until I read the posts. :?: I just bought 3 acres with a home and a seperate rental building it is a residense(grandfathered in).The residense had an interior 6/12 circuit 60 Amp panel fed with 3 # 2 use CU.I felt that the best thing was to place a service rated disc. on the exterior and sink a ground rod replace the existing panel due to other reasons and seperate grounded and grounding conductors when it was replaced.The disc. was fed from 300 ft away and adding a grounding conductor was not an option so I left it fused at 60 amps as original set a 60 amp disconnect and fed 4 wires from there to the replaced panel.Any thoughts other than was this inspected I`m sure that will raise eyebrows.

 

[jwelectric]

The rule concerning a separate building or structure supplied by a branch circuit or feeder is so simple that we just can?t grasp it. Some electricians will stand pat and argue 408.36(A) Exception 1 till they turn blue in the face. This exception states:

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 does not negate 225.31;

225.31 Disconnecting Means.
Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure.

Now that this disconnect is required just where is it required to be located?

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.

There are a couple of exceptions to 225.32 but each and every one of them has some restrictions that will fall outside the scope of a residential setting.

This disconnecting means is required to be suitable for use as service equipment as outlined in 225.36

225.36 Suitable for Service Equipment.
The disconnecting means specified in 225.31 shall be suitable for use as service equipment.
Exception: For garages and outbuildings on residential property, a snap switch or a set of 3-way or 4-way snap switches shall be permitted as the disconnecting means.

Notice the Exception to 225.36. Should a single 120 volt circuit be installed to this separate building then a snap switch will sacrifice for the disconnecting means as long as it conforms to 225.32.

What is so hard about this?
It is obvious that 408.36 is directed to the panelboard and 225.31 ? 225.40 is directed to a separate building and the way I read this there is a big difference between a building and a panelboard.

 

[iwire]

Mike you drooling to bring 408.36 into this when none of what stew has asked has anything to do with that. :lol:

But since you brought it up since our last discussion I did come across another (in addition to the one I posted a photo of) MLO panel that was listed and labeled as service equipment when no more than six OCPDs are installed in it.

The one I posted a picture of was a 600 amp or larger panel this other one I saw was a 100 amp plug in 30 circuit Siemens panel if I recall correctly.

I could use this 100 amp Siemens MLO panel that was listed as service equipment with no more than six breakers as the disconnecting means for a residential outbuilding. 8)

 

[George Stolz]

The rule concerning a separate building or structure supplied by a branch circuit or feeder is so simple that we just can?t grasp it. Some electricians will stand pat and argue 408.36(A) Exception 1 till they turn blue in the face. ... This exception does not negate 225.31;

Whoa up, there. Mike, this goes back to the disconnecting means versus overcurrent protection discussion we had at the end of the thread I linked to above. They are not the same thing.

We can continue discussing that in the thread linked to, I agree with Bob that Stew's thread will get a little messy if we go in depth on that here.

If overcurrent protection is provided (even remotely), then 408.36 is satisfied. Then, up to six handles can serve as the disconnecting means at the remote structure.

 

[mario]

In a Nutshell/Bottom Line ??

In a Nutshell/Bottom Line ??

considering its only 7 am here in AK and I'm still a bit asleep ... do I need a "Disconnect" located "On/In" a Garage/Shop with a 6 ckt panel fed with a 50 amp 2 pole breaker 3 wire/w/grd from my "House Panel ??

Again forgive me if I sound dumb here but wjth all the referenced code sections, I'm still confused ...

 

[iwire]

If this panel you have is indeed rated as service equipment with up to six breakers installed and you have 6 breakers or less installed in it IMO you are all set.

If the panel is not rated as service equipment with up to six breakers installed than IMO you have a violation.

 

[mario]

Thanks Bob ... those were my thoughts also, but its nice to have some one else agree with me ... m

 

[George Stolz]

Mario:

• Yes, you need a disconnecting means at the detached garage/shop. 225.31
• It can be up to six handles by code. 225.32(A).
• Therefore, the six-circuit panel you're referring to, with six breakers installed in it, can be considered one disconnecting means.
• If the overcurrent device supplying the feeder to the garage/shop is not readily accessible, then an overcurrent device must be located at the garage/shop and a lower rating than the breaker supplying the feeder. 225.40.
• The panel must be marked as "Suitable for use as service equipment." 225.36.
• Since you've run an equipment grounding conductor with the feeder conductors, then the neutrals and grounding conductors are kept seperate.
• You must use all grounding electrodes present at the detached structure, or install ground rods if none are present. They are to be connected to the grounding (bonding) conductors in the panel. 250.32(A).

Don't feel bad, it's confusing. Which is why we all argue about it.