Adding a New Garage Circuit

[Ferrino]

My double-garage (made in 1980) appears to have a single 15A, 110v circuit supplying everything (5 receptacles and 2 recessed lights). This includes powering a washing machine, garage door opener, as well as all tools. I've tripped the breaker more than once when using a circular saw.

I was thinking it would be nice to have a new, dedicated circuit for tools etc., at my workbench.

The breaker panel is in the garage and there is currently a ~22 ft. route from the panel to my workbench that is ~80% not drywalled, so it would be straightforward to run and fasten cable to a fresh receptacle before I complete the drywalling.

I was wondering how much an electrician would typically charge to add a new breaker circuit to the panel and leave a long length of cable to run to the workbench? Would a 20A circuit be recommended?

I'm very new to electrical work, so I'm not sure which parts of the work are easy for a novice and which should be left to the pros. Clearly I will not be messing around with the breaker panel, but I think I could run the cable to and wire the receptacle.

Thanks!

 

[vartz04]

not sure why you couldn't do that yourself. seems pretty straight forward. buy a simple electrical work book from Home Depot and see if you think you can tackle it.

 

[zacker01]

I have done alot of electrical work while rebuilding my houses, if I were you, (do you have 200 Amp service to the house?) Id run a 220v circuit into another, seperate panel for the garage. Then you can put each tool (if you have stuff like table saw, band saw, lathe... ) and run a bunch of outlets around the shop. Id leave the box / panel work to a pro though,esp. if you have never did any work in one. its not hard to do but can be daunting knowing that one wrong touch can kill ya..lol but,
A.) why chance killing yourself or burning down the garage?
B.) taking a job away from some electrician who can probably use the $$$.

All the wiring and boxes you can do yourself. (Like Vartz said above, go buy one of those books from Lowes or HD that show you how to wire everything..they are a great book to have around). So, just stick the new panel box on the wall, mount all your boxes for outlets and switches and run wires from the boxes to the panel box and let the ends hang out about 2 feet. Same for the Switches and outlet boxes, let the ends hang out a foot or so. then mark each wire going into the panel box as to what plug it works... Like, 1, 2, 3, 4, 5, 6, 7, 8. where 1 would be the first one on the run and 8 is the last. Also, Id run 20amp circuits, wire and outlets, esp for machines. nd try to keep machine outlets as close to the machine as possible, theres alot of power lost in extension cords. And dont forget, a 240v outlet near the door in case you want to get a welder!!! lol

 

[eljefino]

I bet the elecrician could do it for an hour or whatever the minimal service call is. You can help by drilling 1/2" holes in your wall 2x4 studs where you want the wires to go. Holes should be right about in the middle so exterior and interior nails can't get them. You can look up the codes about holes to get a general idea; if they're no good the sparky will put new ones in anyway, just at his labor rate.

If you have a bunch of blank spaces in your breaker box there'll be no need for a garage subpanel-- the whole thing is in there anyway.

 

[Ferrino]

Thanks all! I love the idea of a separate sub-panel purely for the garage, but I think it's overkill for my setup, as I don't have that many high-power tools. I think I'd just like to have one new 110v/20A circuit sent to my workbench.

I like the idea of me wiring up the 20A outlets and running the cable through the studs, over to the breaker panel, ready for an electrician to hook up to a new breaker (I don't really want to mess with the breaker). What type of cable would I need for a 22' long 20A circuit? And what is the correct way to secure the cable between the outlet and the breaker panel - do I need specific staples, for example?

 

[acer66]

12/2 romex, stables and such but like it was said before you might want to invest in a book.
But you might just run 12/3 just in case you need a second circuit there in the future.
I would also talk to the electrician of your choice first, he/she might not want you to do anything since the electrician is liable for the work.

 

[sberry]

Run 2 while you are at it, if you hire sparkie wont cost much more to stab a couple wires. I would run one for the washer while I was at it. Buy a roll of wire, toss what you don't use on the shelf. It goes up in value and reduces the pain later if you want something else, Small comps can run from 12 as well as the 200A compact wire welders.

Personally I run a panel, just added one to an upstairs remodel, was short of spaces anyway and puts all the second floor power from it. For me I like a garage power setup I could run a welding machine, comp etc, it can be pretty much a one shot deal but like others said a new wire or 2 will be sufficient especially if you have free spaces.

 

[Ryf]

+1 on a dedicated washing machine circuit.

no need to add a sub if the panels right there.

my garage was the same way, except the box was at the other end of the house, so I DID run a box to get the power I needed, but I use my attached as a metal workshop, will be a GREAT upgrade to have the breaker not trip and get work done with less hassle etc.

 

[NUTTSGT]

Like Acer said, 12/2 Romex, it'll be yellow. All wire is color coded now for easy identification, although older 12/2 was white, it'll still be in use in homes.

12/2 is good for a 20 amp circuit, and it's okay to use it on a 15 amp circuit. Do not put 14/2 on a 20 amp breaker.

 

[coolreed]

You must run 12/3 for a 120 VAC 20 A Outlet. Black (Hot), White (Neutral), Green (Gnd).

If you are going to install a breaker, turn the main breaker off to your breaker panel 'before' changing the breaker or running Romex to the panel. This prevents the possibility of flashover.

Hookup is real easy. Running the wire from the panel to the outlet is the hardest part.
Be safe.

 

[zacker01]

You can help by drilling 1/2" holes in your wall 2x4 studs where you want the wires to go. Holes should be right about in the middle so exterior and interior nails can't get them.
.

They sell (or you can make) small steel squares that you nail onto the studs ovr the spot where the wires pass through the stud, this will keep you from screwing or nailing into the wires. you dont need them unless you drill to close to the edge of the stud. They are more usefull if you have 2x4 studs than if you use 2x6. If you have the panel out side you dont need the sub but..I just like the idea of the sub so I can put it away from the main so other people in the house dont confuse the two or shut down garage power by accident. and you can put it closer to where you spend more time so you dont have to run around to hit the breakers if you pop one. lol maybe im just really lazy??? lol

 

[matt151617]

You must run 12/3 for a 120 VAC 20 A Outlet. Black (Hot), White (Neutral), Green (Gnd).

That is not 12/3, nor does he require 12/3. He needs 12/2 with ground. Romex has a bare copper ground wire.

 

[miketyler]

Was just about to say that. 12/3 actually has 4 conductors and includes a red wire, one more than 12/2.

Also, if you are thinking minimalist and/or your panel is full, they have split breakers that will turn one breaker into two. I have separate 100amp panel in my detached shop and panel was full. I needed to add a new 220v circuit for ceiling mounted electric heater. The dual breakers helped me free up two places on my panel so I could have a deidcated 220V breaker.

Hopefully, there's no downside to doing this. I plan to run AC and may do this again to provide another 220VAC circuit.

 

[pattenp]

That's a good option, but only certain load centers can use the mini tandem breakers.

Was just about to say that. 12/3 actually has 4 conductors and includes a red wire, one more than 12/2.

Also, if you are thinking minimalist and/or your panel is full, they have split breakers that will turn one breaker into two. I have separate 100amp panel in my detached shop and panel was full. I needed to add a new 220v circuit for ceiling mounted electric heater. The dual breakers helped me free up two places on my panel so I could have a deidcated 220V breaker.

Hopefully, there's no downside to doing this. I plan to run AC and may do this again to provide another 220VAC circuit.

 

[hmbemis]

not sure why you couldn't do that yourself. seems pretty straight forward. buy a simple electrical work book from Home Depot and see if you think you can tackle it.

I know you said you're not interested in going in the panel, but figure I'd say this for the sake of saying it...

If you have a disconnect for the main panel that is outside the panel itself--like on the meter--then I'd say tackle it because you eliminate any danger by turning off the power to the panel you are working in. If at any point you feel over your head, just remove what you did and call a pro.

If you do NOT have a disconnect for the main panel outside the panel--meaning your "main breaker" is inside the panel--then you should be aware that you will be working around UNFUSED conductors (the meter side of hte main breaker) probably capable of carrying THOUSANDS of amps before they vaporize violently... when you're yanking wires around in the panel, moving your screwdriver, etc, if you happen swing one these items the wrong way you could hit the live conductors and it will quickly turn into a very bad day.

You might say "Oh, it's no big deal to not hit them", but when you're pulling your wire from the top, and your main service is entering at the top, you realize you've got about 1/8" or less of rubber surrounding those conductors protecting you... and you usually are working with at least one 2' long conductor for the new circuit because you've typically got ground buss on one side and neutral on the other...

I guess my point is: If you are at all not comfortable with working in a live panel, then you should call a pro, the few hundred you might spend is well worth not injuring yourself.

That said, I just added a 15A and 20A circuit to my panel the other night for a dedicated sump pump and air conditioning outlet--I have the kind of panel w/ the main breaker in it (so the meter side of the main breaker always stays live)... I wore two pairs of rubber gloves and I make it a point to stay hyper focused on what I'm doing, where my hands are, and where the ends of the conductors I'm working with are. I've added a few circuits myself to the panel and it's def. do able by a "layman" once you understand what to do.

 

[Ferrino]

Thanks all! I have 3 available slots in my main panel. I called a local electrician and he said that if I run the Romex cable to near the main panel, he would install the breakers and hook them up for $150. Does that sound reasonable?

I was thinking of running 12/2 Romex cable throughout and maybe having one 20A breaker (for tools) and then a couple of 15A breakers for lights etc.

For the 20A circuit, would it be a good idea to have a GFCI breaker or is it better to have that protection at the outlet itself?

 

[vartz04]

20 amp breaker running to 2 outlets near where you usually use the high powered stuff.
15 amp breaker for the rest of the outlets
15 amp breaker for lights


put the GFCI on the first outlet of each run and it will protect them all. Probably cheaper to buy 2 outlets than 1 breaker.

 

[eljefino]

^ if he's buying the wire he should stick to one size... 12 gauge. The more one buys, the more they save-- 25 foot rolls are silly expensive. Of course he could stick a 15 amp breaker on that instead of the 20 it'll take, but why?

If he gets a monster roll he can tip the electrician or just chuck it in the attic, it will probably grow in value.

 

[gibjoan]

I hope to find out how to cut metal clad electrical cable with out a cable cutter.
Thankyou
Gibjoan

 

[Ferrino]

Thanks all! I have a question regarding dropping the 12/2 wire from the ceiling down to the workbench level (and on the other side, from the ceiling down to the breaker box level). Although I understand I can surface-mount and put the wires within conduit, I prefer the cleaner look of having wires behind the drywall. In order to staple the wire to the studs between ceiling and outlet/breaker-box (as per code), I'd need to remove a 16" wide section of drywall, right?

 

[acer66]

Someone might correct me but I think you do not have to remove drywall just to stable the cable.

 

[Ferrino]

Someone might correct me but I think you do not have to remove drywall just to stable the cable.

How do you staple the cable to the studs at the appropriate spacing if you can't access the studs? To reiterate, I will be dropping the Romex cable down from the ceiling to workbench level. Thankyou!

 

[acer66]

You don`t, if my memory serves me correctly, a cable fished through a finished wall is exempt from that.

 

[vartz04]

You don`t, if my memory serves me correctly, a cable fished through a finished wall is exempt from that.

I believe i read the same thing when I was in my electrical class. Thats what I plan on doing anyhow when i set up my tv over the fireplace.

 

[Ferrino]

Ah OK, I misread your reply: you meant that I don't need to remove drywall purely to staple the Romex to the studs. Well that would save a lot of time!

 

[Ferrino]

OK, I've now purchased a 250ft reel of 12/2 Romex and will use this to run new 20A and 15A circuits around the garage in new locations. I bought some 1-gang "old-work" boxes for mounting new duplex outlets to the finished drywall and was wondering where I can find guidelines on where you can place new outlets? For instance, are there rules governing how low they can sit relative to the floor? I'd like to have a few outlets below my workbench.

Also, are there rules on where you have to place the old-work outlets relative to studs, given that they just attach to drywall? Or is the limitation controlled by the maximum distance from the box that you have to staple the Romex to a stud?

 

[acer66]

I do not think there are any real rules about the placement of receptacles besides some, I think, when it come to access for disabled people but I don`t think this applies to you.

In general a lot of people will mount the upper receptacles higher than 48" to be able to lean sheet good against the wall and still be able to access the receptacle/switch.

At your workbench I would just mount them where they are the most convenient for you.

It does not matter how far away the old work boxes are placed away from the studs assuming the framing is done somewhat right and you do not have 1/4" drywall on the walls.

If you do not know what is going on in your walls, existing ducting, cables, water lines, etc.
be careful when you start cutting the holes.

You might also have a fire stop right where you want to place your box.

 

[Ferrino]

Thanks - that's great, as I'd love to conceal some outlets at lower levels.

Another question: my current garage 15A circuit has no GFCI protection, so I was proposing to put a GFCI outlet at the start of the new 20A and 15A circuits. Are there any potential problems with this? For instance, I hear some people mentioning issues with them being tripped even when there isn't a fault. One of the circuits will have a couple of T8 fluorescent tubes downstream of the GFCI - could that be an issue?

 

[eljefino]

If your garage would be a black tomb if the lights went out, you might want to split your lights across your two circuits-- or at least put a work bench light or night light on the other.

If your AHJ runs an older version of the NEC you can still use non-GFCI outlets on your ceiling if you're so inclined, for your lights, although flourescents usually get along with them.

 

[acer66]

Good idea or have the lights on it`s on circuit but I am not sure of how much of rewiring the OP wants to do.

OP, if you run 12/3 instead of 12/2 you could use the extra wire for lights at your work bench area.

 

[Ferrino]

1. Why do I need 12/3 for a workbench light? Can I not just feed off the 12/2 run?

2. On the new 20A circuit: what type of extension cord would I need when working away from the 20A wall outlet? For instance, when running a circular saw (rated 12A peak draw, but which has already tripped my 15A breaker) away from the workbench. I assume I need a 20A-rated extension cord? Or is the weakest link now the cable attached to my saw? The 20A power strips/extensions seem to be very expensive and harder to find?

I should probably add - I don't have any devices which have a 20A pin pattern - they are all designed to work on 15A outlets, but have caused my 15A circuit to trip - hence my desire to install a 20A circuit.

 

[acer66]

Yes you could feed the light from the 12/2 but the extra wire is for having the light on it`s own circuit so if you trip the breaker for the receptacles you still have light.
But you might not need it when you have light(s) on other circuits or have other light sources.

The only time your tool cord is a problem is when it was replaced with a wrong one.
You can kill your tool or put a lot of wear and tear on it with an extension cord which is to small and/or to long.

The reason you saw trips the 15a breaker could be that the saw draws more amps at start up and/or you have some other things running on that circuit.

My miter saw which also rated under 15a, trips 15a breaker quit a bit even nothing else is on the circuit.

What length of extension cord are you looking for?

 

[Ferrino]

I'm looking for a cord maybe 20' long. It seems intuitive to use a 20A cord on a 20A circuit, despite all my tools coming with the standard 15A 3-pin plug design.

 

[eljefino]

There are some nice pricey high amp cords sold under the "yellow jacket" name. Lowes has them as does amazon.

 

[Ferrino]

Given the high price of 20A extension cords and power strips, I'm now wondering if I really need a 20A breaker and outlets. Given that all my devices have 15A plugs, I'm guessing that just having a dedicated 15A circuit for my workbench will be sufficient (i.e. the breaker was tripping before because of over-loading from other loads on my single 15A garage circuit, such as lighting etc).

Worst-case: as long as I wire up the 15A circuit with 12/2, I can always convert it to 20A with a fresh breaker and outlets...

What do you think?

 

[bczygan]

No reason to use 15A receptacles and breaker if you wire for 20A.

 

[pattenp]

It's okay by NEC to use 15A receptacles on a 20A circuit. There's no need to buy the actual 20A receptacles that have the T shaped slot on one side.

 

[Ferrino]

It's okay by NEC to use 15A receptacles on a 20A circuit. There's no need to buy the actual 20A receptacles that have the T shaped slot on one side.

Really? What's the difference between them other than the additional slot then?

Also, I've seen 12AWG power extension cords that are only rated for 15A and not 20A. Why is that, when Romex 12/2 is rated for 20A current?

 

[Alchymist]

Really? What's the difference between them other than the additional slot then?

Also, I've seen 12AWG power extension cords that are only rated for 15A and not 20A. Why is that, when Romex 12/2 is rated for 20A current?

12 Gauge cords rated for 15 amps is because of the connectors. As to the 15 amp receptacles not having the slot, it's to prevent 20 amp loads (that have the sideways prong in the plug) from being plugged into a 15 amp receptacle.

 

[Ferrino]

Thanks. I also read that extension cords are stranded (rather than solid core) and therefore need to be sized up a level to match their Romex equivalents in current capacity. That's why 10AWG is needed on an extension, when 12AWG will suffice for Romex.