Running Wiring To Attached Garage

[FarmerPete]

So, I am planning on outfitting my garage to some extent, and I decided I should check on the wiring situation. Long story short, it's not good. It looks like the garage has a single 15a fuse that it shares with 3-4 light fixtures in the house.


Currently I just have two Edison lights, a garage door opener, and two plugs in the garage. I'd like to add 2 or 4 T8 fixtures in the garage. I also would like to add 2-4 additional outlets. I'd like to have a little bit of overhead in case I want to run a compressor or a 110 welder in the future (I don't have either currently).

I took a look at my fuse box, and unless I'm mistaken, I'm running very underpowered. So my house has a main fuse panel in the basement (100a & full). Since the house was built, they added a ~600 sq ft addition. Later, they added a sunroom with a hot tub. They put in a second 60a breaker box for the sunroom in the basement near the sunroom. I've removed the hot tub, and there is very little currently running off of my secondary box. Just some outlets in the basement where the previous owner had a workshop, and there is an empty 220 plug that looks like they had plans to hook up a generator to it.

My question would be this, what do you think would be advisable? The way I see it, I have two options that don't involve replacing my main box. I could run two 20a lines to the garage with 2 or 3 outlets on each. Or could I run a line from my secondary breaker box to my garage and put in a third box inside the garage? Would there be any benefit to that? In theory, I could use beefy wire so that if I ever did upgrade my panels in the basement, I could up the amperage in the garage as well? Thoughts?

 

[MTW]

Don't cobble it any more than it is, add on after add on. Remove the sub-panel from the basement and the unused circuits connected to it. Relocate the sub-panel to the garage and re-feed it from the existing 60 Amp breaker that it's connected to now. Rewire the garage, and remove and cap the circuit that is now shared with the house. Later when you change the the service panel nothing extra will need to be done for the garage. Make sure you install a 4 wire feeder to the garage panel. And back-feed a 2 pole 60Amp breaker to use as a main disconnect (required)

 

[pattenp]

If the sub-panel is installed in the same structure as the main service panel a main disconnect is not required in the sub-panel. But it is a good idea to have a main disconnect in the sub-panel. Also use a main breaker panel instead of a main-lug panel for a sub-panel because it eliminates the need to use a back fed breaker as a disconnect.

Don't cobble it any more than it is, add on after add on. Remove the sub-panel from the basement and the unused circuits connected to it. Relocate the sub-panel to the garage and re-feed it from the existing 60 Amp breaker that it's connected to now. Rewire the garage, and remove and cap the circuit that is now shared with the house. Later when you change the the service panel nothing extra will need to be done for the garage. Make sure you install a 4 wire feeder to the garage panel. And back-feed a 2 pole 60Amp breaker to use as a main disconnect (required)

 

[FarmerPete]

So, if I was going to move my sub panel from the basement to the garage, what would I do with the few things that are currently running to the sub panel? It is running the power for the 3-seasons room (3 lights, ceiling fan, and multiple outlets) and a room in the basement's outlets. It also has a 220 going to an empty plug where I could (in theory) hook up a generator. Now, I don't mind moving that 220 hook up to the garage. I'm sure I could use a generator from the garage just as easily as from the 3 seasons room (I'd need a long cord either way). It also doesn't have a generator disconnect, so I don't think I could legally use it to backfeed the generator into my home's power regardless. However, while I wouldn't mind running the appropriate sized cable from the current sub panel location to the garage and tieing it in to the new sub panel, but I'm not about to mess with the current structured wiring in the 3-seasons room or basement.

Is this the kind of thing that an electrician n00b can handle? My current electrical experience involves replacing switches/outlets. I don't mind buying a book or whatnot. I've got a friend who was an electricians helper for a year that may be willing to help me for a nominal fee. I'm just looking to how much work this would be. I feel like the hard part would be running the wire from the garage to the current sub panel, which isn't exactly technical. I've run CAT5 in my house, and I'm good at researching stuff.

 

[pattenp]

The down and dirty way would be to run another 60A sub off of the existing sub providing the feed to the existing sub is 60A. I not going to say this is the best way to go, but it will most likely serve your purpose. On a side note... do not back feed an outlet with a generator..... it's not safe.

 

[FarmerPete]

The down and dirty way would be to run another 60A sub off of the existing sub providing the feed to the existing sub is 60A. I not going to say this is the best way to go, but it will most likely serve your purpose. On a side note... do not back feed an outlet with a generator..... it's not safe.

I was under the impression that as long as your panel was setup to have a lockout such that the generator fuse and the main fuse could not be on at the same time, that feeding a generator into your fuse panel was a legal and safe.

 

[pattenp]

You are right with what you are saying. I should have said it's not safe to back feed a standard outlet with a generator. You should use a power inlet, not an outlet, that is on a breaker that has an interlock.

I was under the impression that as long as your panel was setup to have a lockout such that the generator fuse and the main fuse could not be on at the same time, that feeding a generator into your fuse panel was a legal and safe.

 

[RickP]

I was under the impression that as long as your panel was setup to have a lockout such that the generator fuse and the main fuse could not be on at the same time, that feeding a generator into your fuse panel was a legal and safe.

True, but the problem is that you'd be backfeeding a sub-panel rather than your main panel. The lockout needs to be setup so that it disconnects the power company main feeder, which can only happen if the generator is wired directly to your main panel. You could use an automatic transfer switch instead of a lockout, but that will be a bit more $$$. The easiest way to use a portable generator is with extension cords. But if you want to wire it into your house, a transfer panel would give you a safe way to get it done:
Generac Transfer Panel

(pattenp beat me to it today! I'm typing a little slow right now...)

 

[RickP]

I'd like to have a little bit of overhead in case I want to run a compressor or a 110 welder in the future (I don't have either currently).

For future expansion in an attached garage, the quickest way to go is to run 6-3 romex inside the walls/floors. That will be plenty big enough for a 240v compressor, or it could feed a garage sub-panel. It sounds like you wouldn't need to use bigger cable than that, but you might be able to go slightly smaller if you know what your loads are going to be. If romex isn't an option, you could run conduit now and then pull whatever size wire you need later.

The big question is whether to feed the garage from your main panel or the basement sub-panel. Are you planning to upgrade your 100A service anytime soon? That's pretty undersized by today's standards, but you might be able to get by with it for a while longer. How far from your garage to each of the existing panels? Adding a sub-panel yourself is do-able, as long as you're willing to read about it until you're confident you can do it right. I recently added a small one in my garage and it wasn't too hard. An attached garage is a lot easier than detached.

 

[FarmerPete]

The big question is whether to feed the garage from your main panel or the basement sub-panel. Are you planning to upgrade your 100A service anytime soon? That's pretty undersized by today's standards, but you might be able to get by with it for a while longer. How far from your garage to each of the existing panels? Adding a sub-panel yourself is do-able, as long as you're willing to read about it until you're confident you can do it right. I recently added a small one in my garage and it wasn't too hard. An attached garage is a lot easier than detached.

I hadn't planned to upgrade my panel any time soon. I really didn't want to spend the money unless there is a reason. I have lived here for 6 years, and I've only ever blown one fuse maybe 2-3 times. Both panels are about the same distance away from the garage. The subpanel may be a little easier since I could run the line with the floor joists. Plus, the main panel is full up right now. I figured I'd use the empty space in the sub before I run off and buy the smaller fuses.

 

[FarmerPete]

True, but the problem is that you'd be backfeeding a sub-panel rather than your main panel.

I agree. The wiring was setup by the previous resident. I'm not sure what they were intending. I know I could manually turn off the main and then open the generator circuit. I just would always have the fear that my wife/kids would screw it up and do something bad. I'm not planning on getting a generator any time soon, so it's not really a big deal anyways. I'd much rather spend my money on fun stuff. The power hasn't gone down here for more than a few seconds in 10 years.

 

[RickP]

I hadn't planned to upgrade my panel any time soon. I really didn't want to spend the money unless there is a reason. I have lived here for 6 years, and I've only ever blown one fuse maybe 2-3 times. Both panels are about the same distance away from the garage. The subpanel may be a little easier since I could run the line with the floor joists. Plus, the main panel is full up right now. I figured I'd use the empty space in the sub before I run off and buy the smaller fuses.

That'll work. But as soon as you add garage lights and outlets, you're definitely gonna need a beer fridge out there...
Then add the compressor, welder, etc. and you might see the power dip more often inside the house. You might end up needing to upgrade your main panel sooner -- I just didn't want you to have to run wire to the garage twice.

You've got space and a spare breaker in the basement subpanel, so you could feed the garage from there. Just make sure the wire feeding that sub-panel is the right size for the breaker protecting it.

But a better solution is to move the sub-panel to the garage. You could still use the existing wire feeding the basement sub-panel -- just connect it to a new wire (of the same size) in a junction box and extend it to the garage. Then run 3 cables back to a j-box in the basement for these circuits:

It is running the power for the 3-seasons room (3 lights, ceiling fan, and multiple outlets) and a room in the basement's outlets.

As long as all your cables are inside walls and joist pockets, you could probably use romex for everything. It's time-consuming, but not all that hard to learn. For the connections, you could take pictures of the current sub-panel and use that as a good starting point, and then post up the photos here to check your work.

 

[MTW]

Pete.

For your consideration, the right way to do it and be permanently done is suggested below. I know it's probably more than you want to spend, but it will pay dividend's in the future, even if selling the home.

The whole reason you have an existing sub-panel, is because the main service entrance panel is too small for the expanded home.

The main panel you have now is a Pushamatic brand, these are now obsolete and the breakers are expensive compared to a newer type. However if you install a new 200A panel that has a generator transfer provision built in, such as this.
http://www.homedepot.com/p/Reliance-Controls-200-Amp-Generator-ready-Loadcenter-with-Meters-TTV2003C/202216485#.UgsmUj-J7RY

Then you could connect all of your house loads to it, including the existing sub-panel loads. Have room for future additions, connect a sub-panel for the garage, and have a legal and "idiot proof" generator connection point.

Then you would have your choice of either old panel for the garage use. The bigger one would also future proof the garage, for tool and equipment expansion.

Making the mistake of back-feeding the house with a generator and forgetting to shut off the service main could kill or injure a lineman working down the street at worst. At best it would damage your generator from trying to run the neighborhood. If you do the generator panel install, then anyone could connect the generator without causing harm or liability.

Just a suggestion, food for thought...

 

[FarmerPete]

you're definitely gonna need a beer fridge out there...

I already have a kegerator out in the garage.

 

[FarmerPete]

Pete.

For your consideration, the right way to do it and be permanently done is.....install a new 200A panel that has a generator transfer provision built in

Thanks for the suggestion. I think what I'll end up doing is getting an electrician or two to come out and give me an estimate on upgrading to 200a service. I may move my subpanel out to the garage myself, as I probably will want one out there anyways, and it's hardly being used as is. If the retrofit was going to cost more than $1500 (which it probably will), I'd have a hard time justifying it to myself (and more importantly my wife) unless I had a clear need to do it. I.E. we start tripping breakers or the main, or I can justify getting a welder and the upgrade would be required for it.

Thanks for the help. You all have been informative.