I lost power to my garage and discovered that the breaker had not tripped but yet the garage had no power whatsoever.
Cutting to the chase: The previous owner had an ‘electrician’ install an everyday electrical junction box below ground about a foot from his new garage, at that time. I could not believe my eyes. Anyway, checking this gooey mess out, I discovered that on of the leads heading back towards the house had shorted itself in two. Can’t imagine why this happened …
So, these may be my only hope of getting this right.
Plan A
If I can pull the old wires out (2 wires in this case), I would like to replace them with three wires: hot, neutral and a ground. The pipe is large enough to accommodate these wires. These wires will run un-cut from house to garage, so this shoud be safe and this old junction box will serve only as an elbow:
Plan B – maybe
If I cannot pull the old wires out, I then may have to cut the pipe leading to the house back about a foot to gain access to some good wire to make a splice, but then what? Problem now is, just how do I repair this in a safe fashion? This splice will have to be waterproof.
Any suggestions will be gratefully appreciated.
Phillip
P.S. Does anyone know why the inside of the junction box is purple as seen in the image?
Replies
I am NOT an electrician, and you should get some advice from some, but I'd consider a "pull elbow" (what we called it, there's probably a better name), which can be sealed. It won't keep water out, necessarily - nothing will keep water out of an underground box except maybe welding it shut - but it will keep critters out. This will work if you have a continuous wire from house to garage; it's not a splice box, as it's too small.
If you do splice, make sure you use one of the waterproof splice approaches. When I worked with a public school maintenance electrician, we used to use split bolts, vulcanizing rubber tape, and electrical tape for mechanical protection, but this was more than 30 years ago. I understand there are some waterproof wire nuts now, filled with an epoxy or something like.
Hello Houghton123.Thank you for your advice.I do not plan to do any splicing, if I can help it. Everything depends on whether or not I will be able to remove this old wire. I certainly hope that will be the case. I will know more in a few hours and get back to all of you.Thanks again.
For God's sake, man, get enough juice to that garage to do something more than open the door! This is a re-engineering project, not a repair job.
If it were mine I would rip out that non-burial conduit and replace it with something larger, then pull a more substantial supply to the garage. The guage size depends on the distance - there are formulas to calcualte voltage drop in conduit based on distance, guage, etc.
Disclaimer: I'm not an electrician, this advice is worth exactly what you paid for it.
Hello wrudiger,I hear you on getting the juice to the garage. You would not believe what I found when I rewired our old bungalow, so this is not much of a surprise to me. I cannot remove the old conduit as this would be a major investment and we've over spent on this house as it is. My only concerns are (1) restore electrical service to the garage (3 wire) and (2) make it as safe a repair as possible. I used 12-gauge wire throughout the house so this will be no different.I appreciate all of your comments and suggestions.
How far is the garage from the house? I understand the "no money" issue, but am concerned that you may be undersizing the wire even for the minor load you plan to place on it. Over, say, 50 feet, you could have enough voltage drop in 12-ga. wire that you couldn't support a 20-amp circuit, leading to more cost than you anticipated in fried garage door opener motors, etc.
Well, depending on which voltage drop calculator you use, 12 AWG wire with a full 20 amp load at 120volts is good for right around 50 feet, but the point is well taken - voltage drop should be taken into consideration for any length of wire.
I thought he was being too conservative also but checked one I have and it says #10.
http://www.elec-toolbox.com/calculators/voltdrop.htm
I tried the first couple voltage drop calculators that Google turned up
http://www.csgnetwork.com/voltagedropcalc.html
http://www.southwire.com/voltagedropcalculator.jsp
and they both came up with 12AWG (I could sit down and figure it out by hand but I'm lazy... :-) ) However, I suppose that there won't ever realistically be a full 20 amp load on the circuit, so if you figure say 18 amps it will be okay.
The garage is very close to 40' from the house, so I think I'm OK with 12 AWG. The wire that is currently installed is 14 AWG, so I don't think that I will be under sizing in this case, but you do make a very good point in loosing voltage over distance. Thanks for your comments.
If you can replace the wire that is the way to go. You need a wet rated wire. Underground conduit, no matter how well sealed is a wet area because of condensaiton.
The common THNN wire is usually dual rated at THWN which is wet rated.
I am not sure, but I don't think that the junction box or conduit body is legal underground because you can't pull through it.
The idea situation would be to cut the conduits and replace the box with an elbow. But looking at the pictures it does not look practical.
You can get underground splice that can be used on direct burial cable. I think that HD and Lowes has them. They have a heat shrink sleave and a goo in then that flows out and seals.
Again this would not be leagal because you can't pull a replacement.
But you could cut back and then install another box for the splice.
If you would going to go that far then I would use a plastic box for the splice and then instead of trying to match up to the other conduit cut it also and then use some flexable PVC conduit to finish it up.
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Hello Bill,Thanks for your post and all of your suggestions and comments.The wire I intend to use is dual rated: THHN and THWN, so I'm OK there. I will measure the OD of this pipe - I think it's 7/8-inch - and see if I can find couples and an elbow to match. Then I'll go from there.However, all of this depends on whether or not I will be lucky enough to get that old wire out of there. My feeling is that if it went in, it just might come out. I'll know more later today. One thing that is very puzzling to me is that as you look at the image of the unopened junction box you see that the pipe 90's to the left, well, the garage is not in that direction: it is directly in line with the short pipe! I will expose more of this pipe this morning and see where it leads. At some point it will have to head back towards the basement where the other end of this wire and pipe enters the house.Thanks for all of your great advice. I check back later with more info once I know a bit more.
Well, there's pipe. You got a major bit of good luck there. You found the junction box quickly as well ... another stroke of luck.
On the 'down' side: small pipe. Regardless of what the code says, pulling even a few small wires in 1/2 PVC is a royal pain.
Anyway ... get the old wire out, and flush / clean out the pipe Pull the old wire with your car if you must. Attach a pull string to the old wire, and have the old wire pull it into the pipe at the same time.
Now ... for the repair ....
You will have some more digging. You will need a hole about the size of a 5 gallon bucket. This hole will be for an "N-9" fiberglass 'box' that you can find at most electrical supply houses.
This box will be quite different from any box you've ever used. Basically a tube with a removable top, it will be open at the bottom. You usually dig the hole a bit deep, than use gravel to raise it up, and level it. The gravel also helps water to drain.
Pull your new wires ... use #10 (#8 won't fit in 1/2" pipe), and run at least four of them. Black, Red, White, Green would be usual.
At the box, leave at least a foot of wire free. Make your connections with the 'direct burial' type of wire nuts, then place in the box .... pointing them so that they will tend to drain.
Why #10? Why 4 wires? I'm having you lay the groundwork for future expansion. While there will be a few other things to do when that time comes, you've made a good start. Just put a wire nut on either end of the red wire, and label it as 'spare.'