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Distance of Disconnects Within Groups

Francis Vineyard said:
"Groups of disconnects" spread out along the exterior wall; what limits the distance between them?Francis
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Your feet.
 
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Francis,

Refer to Article 230.70, 230.71 & 230.72, in the `08 NEC.

It does not state that a specific distance is to be applied when

installing them.....That decision is left up to the AHJ.....The

length of raceways and conductor bends does come into the

equation of location & "grouping" though!

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I agree with North Star but I am not sure if these disconnects are on the exterior wall inside or outside. If you have 6 meters and the service entrance conductors are run outside the building then there is no limit on the length of the conductors. It changes once you enter the building and states as near as possible to the point of entry. Some areas have amendments that allow "X" feet. The NEC gives no length. 230.70(A)(1)

In terms of the grouping that is totally arbitrary. Obviously if the wall is 100 feet long and you have them spread out the entire length then that may be an issue--Obviously the size of the disconnects can keep them apart but how far apart is too far is anyone's call.

It seems the reason I hear is so the FD can get to it quickly. Well that theory is ridiculous when you consider the fact that I can have the meters on one side of the building and the disconnects on the opposite end if I run the services wires on the exterior or below grade.
 
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Dennis,

I have come to believe that the location & "grouping"

of the exterior disconnects has more to do with

[ some ] EC's convenience factor, than practicality,

or Fire Dept. access. :o

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I don't really understand why it is there other than convenience as you said. If the NEC were that concerned they would have a limit on distance
 
Dennis said:
I agree with North Star but I am not sure if these disconnects are on the exterior wall inside or outside. If you have 6 meters and the service entrance conductors are run outside the building then there is no limit on the length of the conductors. It changes once you enter the building and states as near as possible to the point of entry. Some areas have amendments that allow "X" feet. The NEC gives no length. 230.70(A)(1)In terms of the grouping that is totally arbitrary. Obviously if the wall is 100 feet long and you have them spread out the entire length then that may be an issue--Obviously the size of the disconnects can keep them apart but how far apart is too far is anyone's call.

It seems the reason I hear is so the FD can get to it quickly. Well that theory is ridiculous when you consider the fact that I can have the meters on one side of the building and the disconnects on the opposite end if I run the services wires on the exterior or below grade.
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Could it be that when you run it on the exterior or underground that if there was a short circuit there would be less chance of a fire considering the limited overcurent protection from the POCO
 
Gregg Harris said:
Could it be that when you run it on the exterior or underground that if there was a short circuit there would be less chance of a fire considering the limited overcurent protection from the POCO
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Sure, that is why it is allowed on the exterior in unlimited length but not why they must be grouped.
 
$ $ $

When they are grouped, it is easier to take a reading on

the "old style" meters......The new meters are all digital

and can be monitored via the internet.

Dennis [ and others ],

Is there any commentary or historical background on the "grouping"

thingy?

$ $ $
 
I am sure there is but I don't know it. Don at MH seems to be up on that stuff.

If there are multiple service drops from the poco then you can have them spread out. You can have up to 6 disconnects group for each set of service conductors. You see this on larger buildings where you have many tenants. You may have a power drop at both ends of the building.
 
grouping is so that in an emergency ( fire, collapse, etc) emergency personnel can go to one location and kill the power rthey need to ( all or some, whatever the situation dictates
 
codeworks said:
grouping is so that in an emergency ( fire, collapse, etc) emergency personnel can go to one location and kill the power rthey need to ( all or some, whatever the situation dictates
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I disagree for the reasons stated above.
 
The poster that originally posted for old analog style meter reading was the most correct. However, the grouping of disconnects has been a godsend to emergency responders when immediate actions were neeeded to isolate the electrical utilities....

You can do what you want, but if the FD needs the power isolated for safety and/or rescue, are you going to be willing to wait for 30 to 45 more minutes for the power company to show up to isolate power?
 
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