I keep popping the breaker on the one circuit that feeds my (detached) garage. Which is a nuisance, if nothing else, because the panel’s back in the basement of the house.
I know, it’s more than that, it’s the system telling me I’m asking it to do to much. I need more juice.
Currently, there’s a 15 amp breaker, with a direct run of 2 conductor (no ground) armored cable out to the garage. I have more room on the panel: there’s an unused 50 amp breaker for a circuit that used to run an electric plenum heater for the furnace.
I had thought about running new wire, but the problem is the section between the foundation and the garage. The cable is fed through a buried 3/4″ conduit. This whole set-up is probably 30 years old. I’d rather not dig up this area if there’s any way to avoid it.
What are my chances of being able to remove the armored cable and put in something new and heavier gauge? Any tips?
thanks.
Amateurs talk strategy, Generals talk logistics.
Edited 11/17/2008 9:03 pm by PaulC
Replies
Yes, if you can pull the wire, assuming that the conduit integrity is good, then you can easily pull new wires. For room and ease of pulling I suggest pulling heavier single strand wires. You may also want to rearrange things so that you can install a sub panel in the garage instead of relying on the house panel. there are plenty of good reasons to do this aside from convenience.
I refuse to accept that there are limitations to what we can accomplish. Pete Draganic
Take life as a test and shoot for a better score each day. Matt Garcia
Thanks, the sub-panel is a good idea. But first, I need to get the wires out there. I'm still nervous about messing up what I've got now, and ending up with nothing (until I tear up the driveway to put new conduit).Amateurs talk strategy, Generals talk logistics.
If you really have conduit you should be able to pull out the existing conductor, and pull new.
But, I am afraid that what you are seeing is just a sleeve through the wall, and the armoured cable is direct buried.
I have seen some really old conductors, (WW-II era), back pulled out of old conduit by pumping lube in until it was forced out the other end, and using a pulling machine.
The conduit comes through the wall above grade, makes a 90 and goes underground. At the other end, condiut comes out of the ground and runs up the outside wall of the garage for four feet before going in. It might not be continuous, but I *think* it probably is. Of course, it still might be rusted to dust.Amateurs talk strategy, Generals talk logistics.
I am not completely clear here. Do you have armored cable up to where it goes into the conduit? Is it possible you have flexible conduit up to where the wire enters the EMT? Or do you have something like BX that is fed through the conduit? I have not seen that, but I guess that the BX diameter is small enough that it could be done. Conduit that is buried in concrete can remain in pretty good condition. If you have two individual wires going through the conduit, if you have some slack at one end or can easily disconnect one end, you can try pulling on one end and see if the other end moves (you can put some tape on the wire and see if it is pulled toward the conduit). It might take a bit of a pull if there are several bends in the conduit, but if you only have two number 15 wires, it shouldn't take too much to pull it out. You can attach the new wires to the old wires to pull them through, or tie a pull cord or rope to the old wires and then use that to pull the new wire through or, if you forget to attach anything, run a fish tape through the conduit to use to pull the wire through.
The BX runs through the conduit.Amateurs talk strategy, Generals talk logistics.
Slim to none.
Armored cable isn't intended for direct burial, or being buried in a slab. And, after 30 years, that 3/4, assuming it's steel, is probably corroded to dust.
Still, keep looking. You might get lucky. If individual wires were pulled, and they had plastic insulation, you'll probably be able to pull them out without a lot of fuss.
If the armored cable was passed through the pipe, and you're able to pull it out ... run some pipe 'sweeps' up to above the ground, and cap with a junction box. Either use PVC sweeps, or wrap the steel ones with 'pipe wrap' tape. This is especially important for the first 6" in the ground.
A 3/4 pipe ought to have room in it for three #6 wires, and a #8 for ground. That can give you the possibility of having 50 amps in your garage panel. Might as well pull the big wire now.
When you do put a panel in the garage, be sure to bang in a ground rod as well.
I think I'll have to cross my fingers any try it. Sure would be nice to have that much power out there. Right now, I've got it set up as my shop space, with my miter saw, router table, 13" planer and Bosch table saw out there. As soon as I ask the table saw for anything, the lights go out. Thanks for the response.Amateurs talk strategy, Generals talk logistics.
You are not getting 3 #6s in a 3/4", you need a 1" for that. The good news is you can use #8 with a #10 ground for 50a (THHN/THWN) per 310.16 in the 75c column.
The real question is what kind of conduit is it. If this is PVC or rigid it should be OK but if it is EMT, it is probably red dust.
The conduit is steel. I see no sins of corrosion above ground, but below, yes I have some fear.Amateurs talk strategy, Generals talk logistics.
Thank you for the correction, Greg. I was 'winging it."