Switching from two detached buildings

[dwellselectric]

Question I know it is probably in the code book but to be honest I don't have mine handy. But say you have an outside light on a shed and you want to 3 way it from the house and the shed. Is it legal or would I have to install a remote switch. Also if you don't mind the code art. so I could read it when I get my book back. Thank you in advance

 

[hurk27]

Sure its legal, done all the time, but if you run more then one circuit to the shed you can be required to have a ground rod, so just feed the 3-way circuit from the shed circuit. 250.32(A) exception

also this is the only way your shed disconnect can disconnect all circuit conductors. 225.31

 

[dwellselectric]

Interesting I was going to do it at a job but was told by my friend that he did that and the AHJ failed him because he said that the conductors between two 3 ways had to stay within the same structure and can't leave. It didn't make any sense to me so I thought that I'd ask. Thank you for your help

 

[hurk27]

Interesting I was going to do it at a job but was told by my friend that he did that and the AHJ failed him because he said that the conductors between two 3 ways had to stay within the same structure and can't leave. It didn't make any sense to me so I thought that I'd ask. Thank you for your help

Well its been done for years and if you were to ask the inspector for a code to cite, bet he wouldn't come up with one, its not in there, the above two things is all you will fined on that issue that could be called (as long as every thing else was done to code)

 

[dwellselectric]

Thanks for the info

 

[Dennis Alwon]

If the shed has a mwbc or a feeder going to it and then you install another circuit from the house or vice versa would you not be violating 225.30

It's done all the time does not make it code compliant. I have done it myself but I don't think it complies.

 

[augie47]

If the shed has a mwbc or a feeder going to it and then you install another circuit from the house or vice versa would you not be violating 225.30

It's done all the time does not make it code compliant. I have done it myself but I don't think it complies.

I agree.
I see it fairly often and, although it might be a "stretch", I use 225.30(D) to justify it

 

[hurk27]

If the shed has a mwbc or a feeder going to it and then you install another circuit from the house or vice versa would you not be violating 225.30

It's done all the time does not make it code compliant. I have done it myself but I don't think it complies.

But I don't think this would apply if you feed the 3-ways from the garage/shed building?

heres what I believe, lets say the light outlet is on the garage/shed, if you feed the switching also from the garage/shed then your not adding any more circuits.

now lets say the light outlet is on the house, you feed the switching from the house, is the 3-way a point on the circuit in which current is taken? I wouldn't think so, so your not really feeding the garage/shed but you can run into a problem meeting the requirements of 225.31.

but feeding the circuit from the garage/shed with the load on the garage/shed would be disconnected and your not adding any extra circuits, and also meet 225.31 with one disconnect.

now put the light outlet on the house, and feed the circuit from the garage/shed, you will now have one circuit feeding the garage/shed, and a circuit feeding back to the house from the garage/shed, so the garage/shed disconnect requirement will be satisfied, and the house disconnect will be satisfied, but will this be considered another circuit running to the house?
I wouldn't think so because it originates from the house to start with.

ok last one, put a separate service on the garage/shed and the whole thing changes, now you have a violation either way if the load and branch circuit is not on or from the same building, again I don't think just feeding a 3-way is feeding a load

 

[Dennis Alwon]

But I don't think this would apply if you feed the 3-ways from the garage/shed building?

No but then the house would be fed from 2 sources.

now lets say the light outlet is on the house, you feed the switching from the house, is the 3-way a point on the circuit in which current is taken? I wouldn't think so, so your not really feeding the garage/shed but you can run into a problem meeting the requirements of 225.31.

I disagree but I see your point

I wouldn't think so because it originates from the house to start with.

Not sure I follow that logic. The entire service originates at the house but we still can't add extra circuits. With that thinking I could add 6 uf cables to the shed/garage. No?

I would say the wording is sketchy hench the change in the 2011 draft. Change is highlighted

II. Buildings or Other Structures Supplied by a Feeder(s) or Branch Circuit(s) [ROP 4-38]​

225.30 Number of Supplies.

A building or other structure that is served by a branch circuit or feeder on the load side of a service disconnecting means shall be supplied by only one feeder or branch circuit unless permitted in 225.30(A) through (E). [ROP 4-36, 4-37]

Where a branch circuit or feeder originates in these additional buildings or other structures, only one feeder or branch circuit shall be permitted to supply power back to the original building or structure, unless permitted in​

225.30(A) through (E). [ROP 4-36, 4-37]
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[hurk27]

No but then the house would be fed from 2 sources.

How would the house be fed from two different sources when the branch circuit originates from the house in the first place?

I disagree but I see your point

I feel there has to be a load before you can define feeding? if there is no load at the house or visa versa you are not feeding the other building with just a switch circuit? look at the definition of a branch circuit:

Branch Circuit. The circuit conductors between the final over current device protecting the circuit and the outlet(s

Not sure I follow that logic. The entire service originates at the house but we still can't add extra circuits. With that thinking I could add 6 uf cables to the shed/garage. No?

running 6 circuits from 6 different breakers would be a violation of 225.30,
do you think just because you have put a switch in the circuit it changes to a different circuit? it is still the same circuit that left the house, if this was true then they would be many thing that we couldn't do?

I would say the wording is sketchy hench the change in the 2011 draft. Change is highlighted

This change doesn't even make sense in the discussion at hand, it would maybe apply where a multiwire circuit or feeder maybe fed the out building, where there would be breakers at the out building? but in this discussion we are only talking about one circuit, the same circuit that has left the first building to feed the out building, does this circuit some how change to being a different circuit when it comes back?

The whole reason for 225.30 was so there wouldn't be conductors still live in a building when the disconnects was shut off, this is why they only want one source to a building. the whole reason for the wording in 225.31?

 

[Dennis Alwon]

Wayne, if what you say is true then I could theoretically wire from the shed back to the house with say, 6 MWBC since they are all fed from the house.

I think the change makes sense in that it supports one circuit to go back to the original source from the 2nd structure. This would allow the 3 way setup, IMO.

 

[hurk27]

Wayne, if what you say is true then I could theoretically wire from the shed back to the house with say, 6 MWBC since they are all fed from the house.

I think the change makes sense in that it supports one circuit to go back to the original source from the 2nd structure. This would allow the 3 way setup, IMO.

I think I did an edit after your post.

But no, I agree if you have a feeder then it should change, even though the requirments of 230.70 would still be met even with a feeder?

to me this would be like pooring water from one bottle to another then saying you cant poor it back because it changed.

 

[72gs455]

just put in a single pole at each location and feed them from said location and use motion sensors.