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#87283 02/05/04 05:51 PM
Joined: Feb 2003
Posts: 24
I have a 400 amp meter socket, 2- 200 amp disconnect feeding out of this to 2 - 200 amp MLO panels in the house. 175' away from disconnects. This is done by 2-2" conduits 1 from each disconnect to panel, 4-3/0 cu. wires. Panels in the house are next to each other.
Question is. Is this allowed under 230-71 (1999). Something is just telling me that there is something wrong with this.

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#87284 02/05/04 06:29 PM
Joined: Feb 2003
Posts: 169
I don't see a problem.
408.16 requires the panel to have over current protection on the line side of the panel. The 200amp mains comply with the code.

230.70 allows the disconnect to be outside of the building.

#87285 02/06/04 10:02 AM
Joined: Jun 2003
Posts: 681
The disconnects are grouped as per 230.72. The 'main power feeders' as described in 310.15(B)(6) seem to be in compliance. What do you believe to be the problem?


Pierre Belarge
#87286 03/04/04 06:02 PM
Joined: Mar 2001
Posts: 345
If the disconnects are not on or in the same building as the panels then you are right that the installation has some things wrong with it.

Two identical feeders with the same voltage characteristics may not be used to feed the same building.


225.30 Number of Supplies.
Where more than one building or other structure is on the same property and under single management, each additional building or other structure served that is on the load side of the service disconnecting means shall be supplied by one feeder or branch circuit unless permitted in 225.30(A) through (E). For the purpose of this section, a multiwire branch circuit shall be considered a single circuit. COPYRIGHT 2001 National Fire Protection Association.

The house must be equipped with a building disconnecting means if those two two hundred amp disconnects are not mounted in or on the house.
225.31 Disconnecting Means.
Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure. COPYRIGHT 2001 National Fire Protection Association.

I hope that helps.
Tom H

Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous for general use" Thomas Alva Edison
#87287 03/05/04 08:20 AM
Joined: Dec 2003
Posts: 751
I don't know of too many 175 foot houses, so I assume the disconects are remote from the house. If so, then, you need a disconnect on a single feeder in or on the house as previously mentioned.

#87288 03/05/04 09:41 AM
Joined: Feb 2003
Posts: 169
Maybe my first response was wrong!

Ok it's been stated there is a 200 amp disconnect 175 feet from the building.

I think the real answer is in 225.32.

The way it's worded, I'm not sure the diconnect mounted outside, has to be nearest the point of entrance, or any where near the building.

Then we have Exception No. 1:. It would seem that it is implying the disconnect is required at the building location

#87289 03/06/04 07:17 PM
Joined: Dec 2000
Posts: 4,294
Read the original post.
"2-200 amp MLO panels in the house. 175' away from the disconnects".......
"Panels are located next to each other"
As described, there is absolutely no Violation.
(I'm wondering, though why there would be 4-#3/0 wires to a panel in a house. Does it have 3Ø power, or "Superground"?)
Do you mean 3-#4/0?

[This message has been edited by electure (edited 03-06-2004).]

#87290 03/06/04 08:57 PM
Joined: Feb 2003
Posts: 169
I question my answer because I feel 225.32 requires the disconnect to be at the building being served.
If it doesn't require that, would it be ok if the disconnects mentioned were 1000 ft or a mile away instead of 175ft.

[This message has been edited by russ m (edited 03-07-2004).]

#87291 03/06/04 08:59 PM
Joined: Apr 2001
Posts: 449
Electure, I believe it is a violation of 225.32 Location. If the disconnects are 175' away from the (2) 200A MLO in the house how are they at a "readily accessible location nearest the point of entrance of the conductors."? The only way this would not be a violation is if the house is 175' long and the disconnects are located on the house where the conductors enter. 225.31 tells us disconnecting means must be provided for all ungrounded conductors that supply or pass through a building or structure. 225.32 gives us the location for that disconnecting means.

#87292 03/07/04 12:18 PM
Joined: Dec 2000
Posts: 4,294
I think that we just read it differently.
I did think that the service was mounted on the house, and the panels were 175' away in the same structure.
It's not that odd to have a situation like that on a big house (we have lots out here).
I fully agree that if the service was mounted on another structure (detatched garage for instance), there would have to be disconnecting means at the house. [Linked Image]

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