wiring code ? for a detached garage

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I'm building a detached garage with 2nd story living space that is about 14 feet from the house. The two are connected by the deck that also wraps around the house. Basically you go between the house and garage via the deck. I powered the garage via a 100amp breaker on the main box to a subpanel in the garage.
But I've also installed an outdoor light fixture on the door of the garage that opens on to the deck. And I extended the 3-way switches out to a box just inside the door. I did this by running two pieces of uf, 14/3 and 14/2 out to the garage inside the deck joists.
So I have a lighting circuit from the house system extended into the garage and not sharing any of the wiring connections in the garage off it's subpanel. Is this ok code wise? If not is there a way to make it ok?
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jamesgangnc wrote: ...

Don't see anything electrically in violation so as long as the workmanship, etc., meets provisions looks ok to me.
Would recommend a label on circuit at switch where it's breaker is just for posterity.
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On 11/9/2009 11:11 AM jamesgangnc spake thus:

Don't know the answer to the question you asked here, but I wonder about using UF as you did: is it OK to have it exposed like this? I thought it was only supposed to be buried, as its name suggests.
Seems like conduit would be the way to go here.
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Uf does not have to be buried but I can't say for sure if my putting it under a deck is acceptable or not. The deck joists are 2x10's and I have stapled the uf on the inside of one up close to the decking. So it would be very difficult to damage.
The problem with conduit is then I have to transition to the inside wiring. That means an accessible box at each end inside the two structures where the conduit cables can be spliced to normal 14/2 and 14/2. Or running the conduit inside the walls all the way to the boxes. Not very practical on the house side because it is all old work. Just seemed a lot simpler to use the uf so I could run all the way.
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jamesgangnc wrote: ...

I don't have a problem w/ it assuming as you say it's well protected; but then again, I'm not your local inspector... :)

Which harkens back to my comment earlier about workmanship. What are you doing at the entrance(s) now and where are these penetrations?
Would seem there would be the termination/transition points.
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Penetration is 3/4" holes drilled through the framing. Both sides have 2 by lumber inside, 1/2" sheathing, and 2 by pt lumber outside. Both holes are clean and the wire passed through easily. I stapled it at both sides of the holes. Seems just like any other holes through a doubled joist or framing lumber. I did not transition the uf, I ran it inside the walls to the boxes. I don't know of any reason uf can not be usd inside? The boxes are located pretty much right above where the wire comes into each structure. So I have no splices.
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wrote:

Penetration is 3/4" holes drilled through the framing. Both sides have 2 by lumber inside, 1/2" sheathing, and 2 by pt lumber outside. Both holes are clean and the wire passed through easily. I stapled it at both sides of the holes. Seems just like any other holes through a doubled joist or framing lumber. I did not transition the uf, I ran it inside the walls to the boxes. I don't know of any reason uf can not be usd inside? The boxes are located pretty much right above where the wire comes into each structure. So I have no splices.
The UF cable is fine. It must be protected from physical damage, which you've done by stapling it on to the side of the framing.
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jamesgangnc wrote: ...

"Seems like" as compared to "is" as per Code aren't necessarily at all the same... :)
I don't know the specific Code section pertaining to that issue otomh; I'd think it might be addressed to require weatherhead or similar protection at entrance to/from a structure.
My concerns would have to do w/ weather protection and possible rodent damage or similar as well as those unsealed holes being accesses for insects, etc., besides the air leakage from a HVAC standpoint. Again, how concerned I'd be would have to do w/ where they're physically located wrt to the rest of the structure(s), ground, etc,. etc., etc., none of which have anything specific to go on. And, while not big, it is a break in a fire barrier.
You are correct in that there is nothing wrong at all about using the UF internal structure; it's simply more than required there.
Again, I'm not an inspector nor even terribly knowledgeable about the details of Code other than the basics to "get safe" as opposed to "fully-compliant" and certainly on the farmstead have places where expediency has played a role. :)
But, at an entrance/exit like this I'm pretty sure I'd have at least put a weather seal on the outside at each location in a residential location unless it is really very well protected and I'd think there wouldn't be a vermin problem, etc., as mentioned (but out here, we got enough stuff that anywhere there's a nook or cranny there's gonna' be some critter/bug/whatever ya' don't want inside looking at it as a wonderful place to nest or use as a freeway. :( I've been other places that wasn't such a big deal as didn't seem to have so many pests for some reason (or at least different ones; we don't have squirrels here to put up with is one advantage. :) )
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David All of the type UF cable presently sold in the US is listed and labeled as sunlight resistant and is perfectly acceptable for exposed runs except were subject to physical damage. I have used a fair amount of type UF as indoor wiring in barns were it's resistance to moisture and the corrosive fumes of animal waste make it the cost effective cable of choice. -- Tom Horne
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Do you have any squirrel insulation eaters? ww
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are separated in the garage sub panel, and a grounding electrode system is installed at the garage and bonded to the grounding buss in the garage panel, your 3 way system should be fine.
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This is an interesting situation and a judgement call: does the deck connecting the two habitable spaces make the whole thing one structure? You should ask your local electrical inspector. If it is one structure, then there is no extra complexity, so let's assume for discussion they are separate structures.
Given two structures, did you install the required grounding electrode system at the garage? Did you provide a main disconnect, or arrange for six or less breakers in the garage subpanel? I assume you used a 4 wire feeder and kept the grounds and neutrals separate.

See <http://forums.mikeholt.com/showthread.php?t 5699> Apparently 225.30(D) of the 2008 NEC allows what you have installed.

Hopefully you stayed 1.25" away from the edge of the deck joists, as is required when running parallel to the framing members.
I'm curious to ask why you needed to run 14/3 and 14/2 to the garage 3-way switch. 14/3 would have been enough to provide two travelers and a common; what does the 14/2 provide? If you were to provide power for any other garage loads from the 14/3 and 14/2 UF, then that would be a violation of 225.30.
Cheers, Wayne
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Not part of my question, but yes, I ran 4 conductors in conduit from the main panel to the panel in the garage. I have a main breaker in the garage panel. I tried to keep it to 6 breakers but I couldn't. The garage has a heat pump with backup resistance heat and its own hot water heater. Neutral and ground are separated in the garage panel.
I ran the 14/3 uf to the three way switch. The existing switch in the house was a 3-way at the termination of a 14/3. I replace it with a 4- way and continued on with the new piece of 14/3 to the new 3-way in the garage. The 14/2 uf runs from the existing outside light circuit in the house to the exterior light fixture on the garage just ouside the entrance door on the deck.
The house does not have "front" and "rear" doors, rather it has doors on each side of it with the deck wrapping around one side. In this old picture the garage is now located where you see stairs in the lower right corner. I wanted a person located in either structure to be able to turn on the outside lights on the deck.
http://www.jamesgangnc.com/bighouse.jpg
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All sounds great, although you didn't mention anything about a grounding electrode system at the garage.

So you have:
House Garage Garage House Other House Power --14/2-- Light --14/3-- 3-way --14/3-- 4-way --14/3-- 3/4-way Fixture Switch Switch Switches
That makes sense and explains having both a 14/2 and 14/3 between the house and garage.
So to reiterate the answer to your original question is that NEC 225.30(D) provides the necessary exception in your case to allow both a feeder and branch circuit to serve the garage from the house. For good measure, you could put a note on the main disconnect on the garage warning that the exterior light and switch are served by a separate branch circuit from the house, although it is not required.
Cheers, Wayne
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Wayne Whitney wrote: ... Wayne, you obviously know Code particulars at least reasonably well, what about the question of the mechanics of the penetration thru the exterior walls? Does that have any specific provision? Seems like would, but I don't know if does or where it would be other than for a service entrance which this lighting circuit isn't.
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I can't be 100% sure, but I don't think the National Electrical Code would address that. If your building rots out, the NEC probably won't care, as long as the cable isn't exposed to damage. :-) Maybe the building code would address penetrations? Common sense says the penetrations should be weather tight and properly flashed.
Cheers, Wayne
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The penetration under the house is in the crawl. I usually squirt some caulk or stuff a bit of fiberglass into the holes. The crawl is by no means completely sealed now.
Your list of items basically captures what I have but there is also house fixtures on the same switches. On the house walls where the deck is there are 6 wall mounted light fixtures. There are no additional switches, in the house a 3 way and a 4 way, in the garage a 3 way. In the picture you can see a couple of the wall fixtures on the windows. It's a lake house, that's why the "back" has all the windows and the ext doors enter form the sides.
Truth be told I am still installing the garage feeder system. I do have the conduit and wires run and a box put up. I still need to install ground rods at the garage. It's 2 now isn't it? That seems pointless to me. Perhaps it's to provide redundancy after the satellite tv guy disconnects one of them, yukyuk.
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jamesgangnc wrote:

Ground rods are a rather poor electrode. The NEC requires a resistance to earth of 25 ohms or less for a rod. If not, a second rod is added and there is no required resistance. Resistance is not easy to measure, so it is easier to install 2 rods. For new house construction a "concrete encased electrode" is usually required, which is a good electrode and eliminates the ground rods.
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The earth's not really much of a conductor for low voltage, low cycle ac anyway. I have serious reservations that a short from a "hot" conductor directly to an earth ground would pop even a 10 amp breaker.
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jamesgangnc wrote:

The earth connection is not intended to trip a breaker (and such a use is not allowed by the NEC). There has to be a metal path starting and ending at the transformer. That involves the neutral-ground connection required at US services. If you have a drill with a ground wire, and there is a hot-to-case short, the path is drill ground wire to branch circuit ground wire through service neutral-ground bond to service neutral wire to transformer. Much of the "ground" wire function is a "bonding" function. The term "ground" does not help understanding this function.
Your garage has a ground wire back to the house service. Some older garages don't have a ground wire, but the feeder neutral and garage grounds are bonded at the garage, just like at the service. (No longer allowed in new wiring.)
The "earthing" function of the "ground" keeps the house voltage at a reasonable potential with respect to the earth, provides a sink for some surges, and is likely to blow high voltage fuses if a high voltage distribution wire crosses with the wires to houses.
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