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Advice needed on overhead wire from house to detached garage

Advice needed on overhead wire from house to detached garage


  #1  
Old 07-28-05, 06:13 PM
apoole
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Advice needed on overhead wire from house to detached garage

Background:
We recently bought an older house, and I knew up front that there was a lot of work to do. The house still had some knob & tube wiring, with some of it running through a mixture of blown-in and fiberglass insulation. Mapping out the circuits before cutting power to the knob & tube, I also discovered that almost half the house (including bathroom, dining room, refrigerator and the detached garage) were all on one 20 amp circuit - and some of that was being powered by the knob & tube.

I've put new circuits in for the bathroom & kitchen lights, but I'm concerned that the previous installation for the detached garage wasn't done correctly (given all the half-a## stuff I've found so far).

My Question:
Is 12-2 sufficient for running a single 20 Amp circuit about 120 feet to the garage? All I'll have in the garage is a light, one receptacle and the garage door opener. This isn't a workshop-just a parking place.

The existing installation had the wire leaving the house, running about 30 feet to a light pole, powering the light and a receptacle on the pole, then underground (and under the road) to the garage. The existing wire running underground is 12-2.

The overhead wire supplying the garage is at the opposite end of the house from the service entrance, although both the light pole and the utility pole are next to each other (the utility pole is higher so the wires aren't near each other).

Any thoughts/advice would be helpful.
 
  #2  
Old 07-28-05, 08:53 PM
J
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Is 12-2 sufficient for running a single 20 Amp circuit about 120 feet to the garage?
12/2 is marginal. I'd probably recommend you step up to 10/2. For future expandability, you might consider 10/3.

But you say that you have an existing 12/2. Are you talking about adding a second one? If so, that's not allowed. You aren't allowed more than one feed to a detached structure.
 
  #3  
Old 07-29-05, 07:45 AM
apoole
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Thanks for the feedback. I am amazed at how much information is shared on this forum and am very happy to have found it.

To clarify what I meant about the existing 12-2:

First, this isn't a primary residence, it's a lake cottage, and I have a long list of items (and associated expenses) that need attention. As long as I can achieve safe and servicable, I'll settle for sub-optimal for the short-term. Much further down on my list is some landscaping work that would be a better time to replace the overhead cable and run the 10 gauge wire.

Inside the house, power was running on the knob & tube to a point that it was wired to (not sure of gauge, older fabric covered three wire cable). That left the house in a pseudo-service head arrangement where it was spliced to (again not sure of gauge) cable that ran overhead to the light pole. From there it powered the light, down to an outlet (that isn't GFI - on my list to do) and from there under the street (maybe 30 feet) to the garage. The wire coming into the garage is 12-2. I was hoping to simply replace the part of the circuit that runs between the panel and where it leaves the house.

What are the risks with leaving this with 12-2? If I'm going to ruin a garage door opener motor because it's not getting enough power then maybe I have to bite the bullet and upgrade the cable.

Again, thanks for the feedback.
 
  #4  
Old 07-29-05, 08:37 AM
S
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I am not sure about all the rest of this, didnt take time to digest it but 12 will run a common garage door opener without problem for quite a ways.
 
 

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