Is 14-3 ok for receptacle run?

[sideways]

I just bought 250' of 14-3 type NM-B wire. I planned on running this in my garage to connect about 15 -18 receptacles that will be used for bench grinder, desktop drill press, sander, and various "plug in" tools. Other than my son-n-law joining me in the shop occasionally, its usually only me so, I don't foresee more than one tool being used at a time very much. Then, I read a couple posts last night where someone said #14 was really useless because it limited your flexibility with different breakers. I'm definately not an electrician and am learning a lot on this site. Do I need to exchange the 14-3 for #12? I was also planning on running the same wire over the ceiling to connect approximately 10 shop lights and I was going to put it on a separate breaker.

 

[bww_mnm]

14g will limit you to 15A circuit. For a little additional $ ($20?), you could use 12g which will allow you to use 20A breaker.

15A were installed by my builder in garage. I added 20A circuits.

 

[sideways]

Thanks...that's what I was afraid of. This is a new shop and I don't want problems down the road that could be easily avoided now...for a couple dollars more. How many receptacles then, are recommended for a single line from the 20A breaker?

 

[Steevo]

Although NEC will allow more, most stay at 6 or less 20a receptacles per 20a breaker/circuit.
Also, you only need 12/2 with ground, not /3 for 120v/20a circuits.

 

[sideways]

Thanks Steevo...that'll require a few more breakers for the total number of receptacles I had planned. Don't really know if I need that many receptacles, but from reading the site, got the idea to put a few higher on the wall for clocks, signage, etc. and basically just space them around pretty evenly. Its a 30x50 building with 10' ceiling. I guess I could use fewer and walk a couple feet further to get to one....thanks again..

 

[kb2tha]

3 wire will allow you to run two separate circuits with one cable. You would use the neutral (white) for both circuits and alternate the hot, black outlets 1,3,5,7, etc. and red 2,4,6,8, etc. This is pretty commonly done.

I will either wire the entire building with 12 wire or use 12 for outlets and 14 for lighting circuits or switched outlets for signs, traffic lights etc.

Each garage receptacle circuit needs to be ground fault protected.
Ken

 

[aandpdan]

If you have the opportunity to add the extra outlets now, do it. One thing that gets to be a pain, and a safety hazard, are extension cords. It's not just a matter of walking a couple of feet, it's using your shop to the fullest.

I'm not sure what you use your shop for but 30x50 is good sized. Do you have a subpanel in it?

 

[sideways]

I have no electricity at all as yet...running all the wires before engaging the utility co. to run a feed to my building. I was going to install a 100 amp service when the power comes in and just want to have everything connected properly. Will run a separate circuit for the 225A Lincoln welder which is 50A and probably the biggest draw that I have. Not sure what the over head lights will use...but plan on using a number of 4 ft fluorescents. I will use the shop for simple tinkering, maintaining my grandkids quarter midget racers and simply having a nice place to do what I want...just want it to be nice..

 

[Steevo]

Those convenience outlets up high for stuff like clocks, drop lights and beer signs can be 15a and 14/2 wire, and you can put all of 'em on a single circuit. Unless you plan to feed a power tool or electric motor from them.

 

[bczygan]

The way I approach electrical capacity for a shop (Or any space) is to do the highest and best test. I imagine the highest and best use I might ever make of the space and plan to supply that capacity. I at least put in a sub panel of adequate capacity to serve that maximum. Then just populate it with the breakers needed now. Especially if the garage or shop is detached, it is easier to take 1 big supply line out there now. The advice above, about lighting and power on separate circuits is good. Also, put alternate power outlets on different circuits. More wire but less chance of overloading a circuit. Also, you can put a box and not fill it with an outlet. Start with a maximum equipment and lighting list and work backwards to get total loads. Think of things like:

Power:
Equipment:
Welder
Compressor
Blast cabinet
Lathe
Disc sander
Vertical or horizontal band saw
Mill
Drill press
Grinder (horizontal and pedestal)
3 phase power?

Woodworking equipment:
?
?
?

Misc.:
Furnace or heaters
Fridge
Freezer
Microwave
Coffepot
TV
Stereo
DVD
Subwoofer
Clock
Smoke and fire detectors
Alarm system and horn power
Fans
Computer (Dedicated isolated circuit)
?
?
?

Lighting:
General lighting
Task lighting
Emergency lighting?
Security lighting (Outside)
Also think of running wiring for security, phone, computer, TV, speaker and intercom service.
Do you have all the hot and cold water, gas and drainage you need?
How are you heated?

And I never use 14ga. (That way I can later get power from any circuit.) Also, carefully label and record all circuits and photo all wiring and plumbing in walls before covering.

 

[Charles (in GA)]

3 wire will allow you to run two separate circuits with one cable. You would use the neutral (white) for both circuits and alternate the hot, black outlets 1,3,5,7, etc. and red 2,4,6,8, etc. This is pretty commonly done.

I will either wire the entire building with 12 wire or use 12 for outlets and 14 for lighting circuits or switched outlets for signs, traffic lights etc.

Each garage receptacle circuit needs to be ground fault protected.
Ken

I would suggest that anyone who is not very familiar with multi-wire circuits stay away from them. As you noted, you need GFCI protection, and getting a successful, functional GFCI installation with a multi-wire circuit is problematic. Do it just right, it works, do one thing wrong, it doesn't work and you cannot figure out why.

Charles

 

[MrMark]

Can't share neutrals upstream of a GFI. Can't be done. Forget it. Downstream it's OK, but why bother. Stupid concept to begin with. There is even 12/2/2 now if you don't want to run two 12/2 cables.

 

[Aceman]

Can't share neutrals upstream of a GFI. Can't be done. Forget it. Downstream it's OK, but why bother. Stupid concept to begin with. There is even 12/2/2 now if you don't want to run two 12/2 cables.

You realize your service wires coming into your panel share a neutral right?

Hopefully, you just said it backwards and meant you can't share a neutral AFTER the GFCI.

 

[Falcon67]

Seems like a **/3 run with GFCI protection at the head end requires a dual GFCI breaker. Not sure how else you would do it. 12-2-2 would work well, wonder how that compares in cost to individual spools.

 

[mrb]

dont run MWBC in garage (multiwire branch circuit, 12/3 with shared neutral) as you will be forced to install a GFCI receptacle for every outlet instead of being able to use a GFCI for your first receptacle and feed the downstream outlets from its load side. You also have to feed it from a breaker with a handle tie, so everything goes out if you trip a breaker.

take back the 14/3 and get 12/2

supply the lights from their own circuit, dont have them on the same breaker as receptacle outlets.

 

[MrMark]

You realize your service wires coming into your panel share a neutral right?

Hopefully, you just said it backwards and meant you can't share a neutral AFTER the GFCI.

That is what I meant. To me upstream means "after" the GFI although I am not entirely comfortable with that terminology and probably messed it up. Does upstream not mean "after"?

 

[MrMark]

I looked up downstream and upstream and I'm still not comfortable with those words. They appear to depend on current (water) direction and the source of the water so I am just going to banish them from my vocabulary as they are imprecise at best.

 

[walrus]

dont run MWBC in garage (multiwire branch circuit, 12/3 with shared neutral) as you will be forced to install a GFCI receptacle for every outlet instead of being able to use a GFCI for your first receptacle and feed the downstream outlets from its load side..

Huh? If you pigtail the neutral to 2 different GFCI recepts and go with the load side you only need 2 GFCIs and regular outlets downstream

 

[MrMark]

Huh? If you pigtail the neutral to 2 different GFCI recepts and go with the load side you only need 2 GFCIs and regular outlets downstream

Umm, yeah, but you're still going to have to use 2 12/2 cables to do it this way from the first box where the 12/3 comes in so it is kind of pointless. The whole thing is kind of pointless and that has been my point that it is pointless and leads to nothing but confusion and screw-ups so that someone can save one white wire to the first box. I could review 100 of these set-ups and probably find 10 done correctly.

 

[walrus]

Umm, yeah, but you're still going to have to use 2 12/2 cables to do it this way from the first box where the 12/3 comes in so it is kind of pointless. .

Its not pointless if you have a long run, Wire is expensive. I don't see it as confusing at all, maybe some folks do?

 

[MrMark]

If it wasn't confusing then it wouldn't get screwed up as much as it does, including by people doing it for a living. Let's see one white wire in 12 gauge is what .16 foot? 100 feet equals 16 dollars. Compared to the other factors involved, e.g., the cost of breakers, the cost of labor, the cost of screw-ups, the cost of safety, the cost of later confusion, the cost of tying up more panel space with double pole breakers and inconvenience of tripping both sides, the 16 whole dollars doesn't seem real big. And 100 feet is unrealistic too.


edit: fixed wire cost

 

[mrb]

Huh? If you pigtail the neutral to 2 different GFCI recepts and go with the load side you only need 2 GFCIs and regular outlets downstream

yeah but the MWBC only gets you to the first set of receptacles, then you need neutral per circuit after. This combined with the hassle of having the 2P breaker makes it not worthwhile.

 

[walrus]

yeah but the MWBC only gets you to the first set of receptacles, then you need neutral per circuit after. This combined with the hassle of having the 2P breaker makes it not worthwhile.

Ok but thats not what you said originally. MWBC are a common practice, I've seen them screwed up, I've seen them work fine. If the loads are balanced you'll generate less heat in the conduit or cable. It may save derating hassles depending on the application. In a basic garage who knows if its worth it but its not wrong to do

 

[MrMark]

It's not wrong but you need to be fairly advanced to do it right. I wouldn't suggest any homeowner attempt it unless highly skilled and educated on electrical.

 

[MrMark]

Kinda on this same topic, is the hot ticket on garage electrical design for receptacles to run two recepacles in each box (doubles) and have two separate circuits at each box. Label the plugs "A" and "B" and that way you can plug two heavy loads right at the same spot?

 

[sideways]

Guys - I appreciate the informed debate and it appears to me, that 12-2 is what the doctor is ordering here for my basic receptacles. I think I could alternate the hots on every other receptacle in order to get two separate circuits from a single run, but the GFCI requirements have honestly confused me. I have a close friend who is a licensed electrician and he's coming over in the morning and we're going to walk through the layout and wiring plan. You made me think of the things I might potentially add in the shop, such as bandsaw, grinders, sanders and I remembered that I want to put at least one Resnor heater...maybe two, so I suspect they will need to be on a separate circuit, or perhaps a separate circuit for each...if it turns out that I need two, but I haven't determined that as yet....Great ideas, and good information....this is great site. I was in Lowes today and was looking at 100amp panels. they have a mix of different numbers of 15 amp, 20amp and other breakers, with various amounts of remaining space, so I'm going to have to figure out what I need and install it. I will return my 14-3 wire and buy less of it to use for my "special" wall items and for the ceiling lights. Thanks again guys...

 

[kb2tha]

I will return my 14-3 wire and buy less of it to use for my "special" wall items and for the ceiling lights. Thanks again guys...[/QUOTE]

Shouldn't need less of it unless you are wiring in some 3 way switches. For those will need some 14-3. For your regular lighting circuits, 14-2 is what you want. Even the spacial wall items (clocks, signs etc.) can run off of 14-2. Some of my signs I have controlled through a switch. Circuits using 14 ga. wire are protected with a 15 amp breaker.

I didn't intend to get a big debate going over the 3 wire with alternating circuits. Only stating that it is possible.
Ken

 

[sideways]

ooops...you're right. 14-2 is all I need. Thanks. The debate is healthy. I asked my friend about using the 3 wires, alternating hots and creating 2 circuits and he agreed it could be done and said he knows how to do it....so, I may end up saving some wire and getting everything wired intelligently in the process. At the end of the day, in addition to having a properly functioning shop, I want people to say it was planned well and done smartly....

 

[Kevin54]

Anytime you can run 12/2 w/g vs. 14/2 w/g I would run the 12/2. It may be a little more expensive initially, but the safety factor makes up for it. I have seen a lot of circuits ran in 14/2 connected to a 20 amp breaker. Not a good thing.
As far as the upstream/downstream meaning, I always looked at upstream as starting at the breaker panel or the "source" and downstream everywhere afterwards. I may be wrong on that also but that's the way I have always known it.

 

[MrMark]

Kevin, you are right on the upstream/downstream water reference meaning. I never get these terms straight so I shouldn't use them.

 

[Gooch]

Anytime you can run 12/2 w/g vs. 14/2 w/g I would run the 12/2. It may be a little more expensive initially, but the safety factor makes up for it. I have seen a lot of circuits ran in 14/2 connected to a 20 amp breaker. Not a good thing.

that doesn't make 12-2 any safer than 14-2, they make plenty of different size breakers and there is physically nothing keeping me from putting 12-2 on a 30A breaker or larger. which would be just as dangerous if not more so than 14-2 on a 20A breaker.

 

[Kevin54]

that doesn't make 12-2 any safer than 14-2, they make plenty of different size breakers and there is physically nothing keeping me from putting 12-2 on a 30A breaker or larger. which would be just as dangerous if not more so than 14-2 on a 20A breaker.

I didn't mean one outlet or a couple of lights on a 20 amp breaker, I mean multiple banks of lights and outlets, running high draw equipment, saws, etc, all ran to one 14 amp breaker. Heck a lot of new houses around here, all they run is 14/2 for ease of installation and the fact that they can backstab the outlets

 

[Gooch]

I didn't mean one outlet or a couple of lights on a 20 amp breaker, I mean multiple banks of lights and outlets, running high draw equipment, saws, etc, all ran to one 14 amp breaker. Heck a lot of new houses around here, all they run is 14/2 for ease of installation and the fact that they can backstab the outlets

all i'm saying is the exact same thing can be done with #12. in fact the other day i found a pair of #12s tied to a 60A breaker. was about 10-12 rec. in the run.