Wiring 2 switches on one circuit

[mikey111k]

Hi everyone. This is my first post, i have been lurking for a while and have learned alot and been inspired. I am working on redoing my 2 car garage and am ready to do the electrical but i wanted to find out if what i am thinking is correct.

I am running a sub panel to the garage and feeding everything out of that. What i need to confirm is my wiring scheme for my lights. I will have 4 1 gang outlets in the ceiling (8 plugs total) to power hanging shop lights and ~8 pot/recessed lights in my soffit storage area (got this idea from this forum). All of these will be feed from one breaker or circuit from the sub panel but will work off of two individual switches, one for the shop lights and one for the recessed lights. Due to the location of my panel and switches i will have the power coming into the lights and the switch will be at the end of the circuit. Attached is my best guess on how i will need to wire this circuit. Let me know if i am even close to correct. For simplicity i showed each branch with only two lights but one will contain 4 for shop lights and the other will be ~8 for recessed. I assume that once i get the layout right i can keep linking in more lights as needed.

Once i get a little further along with the whole project i will start a thread showing what i have done to the garage.

Thanks for the help.

Michael

 

[porcupine73]

Hm, I'm a little confused on the sketch, it looks like the lights are wired in series?

 

[Charles (in GA)]

Wired in series like a Christmas tree light string "when one burns out they all quit" and the bulbs will be only getting about 60 volts each (in the sketch).

If using Romex, I would use 12/3 w/grd (or 14/3 w/grd) and carry the black straight to the switch, pigtail the white at every box to supply the lights with a neutral, and pigtail the red at every box to supply the lights with a switched hot. (expect to physically cut the entire Romex at each box and make your splices with the Red in/Red out/Red pigtail and White in/White out/White pigtail and the Black in/Black out).

You could use 12/2 w/grd (or 14/2 w/grd) from the breaker thru the initial junction box and on to the first light fixture. From the first fixture in each run, it would need to be 3 wire w/grd.

Current code requires you carrying a neutral to the switch box, even if you don't use it, so at the switch, hook the black and red to the switch and cap the white.

The ground, of course, will also be pigtailed at each box to supply the fixture and box (if metal) with a ground.

Charles

 

[Steevo]

The way you've drawn it, I believe a bulb failure in one can light will shut them all down, and you may also shorten bulb life by drawing downstream current through the filaments of the bulbs upstream.
The fluorescents may pose different issues. I'm not sure you can wire the ballasts in series like you'll end up with.

Why not just run a 14/2 from each switch back to the junction box, and splice your switches in there, or better yet, use 14/3 and put 3-way switches at both ends.

 

[mikey111k]

Thanks guys,

I definitely don't want the whole line going down if one light goes out. That's something i did'nt even think of. Attached is my attempt to do what Charles explained. Hopefully i understood it correctly. I have it shown using 12/2 from the panel to the first light then 12/3 for the remaining lights in series. I could use 12/2 from the last light to the switch but i kept the red color for clarity.

On a side note this will be all Romex with no metal boxes of conduit.

Steevo - Good point about shortening bulb life when pulling for a down stream load.

Let me know if this looks right.

Thanks
Michael

 

[Charles (in GA)]

Thanks guys,

I definitely don't want the whole line going down if one light goes out. That's something i did'nt even think of. Attached is my attempt to do what Charles explained. Hopefully i understood it correctly. I have it shown using 12/2 from the panel to the first light then 12/3 for the remaining lights in series. I could use 12/2 from the last light to the switch but i kept the red color for clarity.

On a side note this will be all Romex with no metal boxes of conduit.

Steevo - Good point about shortening bulb life when pulling for a down stream load.

Let me know if this looks right.

Thanks
Michael

That looks correct. The way you had it, the bulbs would last forever since they would be running at half voltage (each) and about half brilliance.

Friend of mine wanted to heat the plumbing at the well head on her deep well. Someone had built a little 4x4x4 "dog house" over the slab of the same size to protect her tank and pipes and wiring. I had hand dug the trench to the well and connected the wires and plumbing for her, but never thought to carry 120v out there, just 240v with no neutral. I took a section of 2x6 and routed some groves in it and screwed two porcelain sockets to it and wired them in series, came off the hot side of the pressure switch with a piece of SO cord and a 20 amp 240 cord end receptacle, and put a matching plug on cord for the lights. Both lights work perfectly, just that if one burns out, the other doesn't work. I simply told her to always change them in matched pairs.

Charles

 

[mikey111k]

Thanks Charles.

I have one other question. The 'lights' in the ceiling are actually outlets that the shop lights plug into. I assume that the recomendations that you guys made are the same if they are outlets or lights? If outlets are wired as I showed in my first diagram they would have the same issues as described earlier?

Thanks
Michael

 

[porcupine73]

It doesn't matter if they are outlets or lights, for this purpose you want them wired in parallel, not in series.

The two switches you show - will they be located right next to each other or in the sam box?

 

[mikey111k]

Yes, the switches will be in the same box right next to each other. Does this pose a problem or offer another wiring option?

I attached another diagram. I made the one branch outlets so i could visualize it a little better. I think i have it right now????

Michael

 

[McDowell]

Yes, the switches will be in the same box right next to each other. Does this pose a problem or offer another wiring option?

Jump your power from one switch to feed the other and then feed back to your second set of lights. You can eliminate your junction box this way.

You'll need to run 12/2 from your panel to the first receptacle then switch to 12/3 from there to the next 2 receptacles and to the switches. You can then switch back to 12/2 from the switches to the remaining 3 lights. See my revision of your diagram (attached). For simplicity sake I 've shown the feed to the switches as red the whole way through.

 

[buzz4041]

Why are you putting GFCI receptacles in ? Sounds like added cost and a waste. Wire light fixtures up directly. Run a romex from the panel to the switch box. Install a romex to each string of lights from switch box. Twist all nuetrals together and wire nut. Twist 2 pigtails to hot from panel and wire nut and hook up pigtails to switches. Twist grounds together and put pigtails to each switch. Wire up switch legs from each romex to string on each switch. No extra JB needed.

 

[MrMack]

That looks correct. The way you had it, the bulbs would last forever since they would be running at half voltage (each) and about half brilliance.

Friend of mine wanted to heat the plumbing at the well head on her deep well. Someone had built a little 4x4x4 "dog house" over the slab of the same size to protect her tank and pipes and wiring. I had hand dug the trench to the well and connected the wires and plumbing for her, but never thought to carry 120v out there, just 240v with no neutral. I took a section of 2x6 and routed some groves in it and screwed two porcelain sockets to it and wired them in series, came off the hot side of the pressure switch with a piece of SO cord and a 20 amp 240 cord end receptacle, and put a matching plug on cord for the lights. Both lights work perfectly, just that if one burns out, the other doesn't work. I simply told her to always change them in matched pairs.

Charles

Note! I am not a professional Union Electrician! and you may want to consult a Professional Electrician about what I have posted.

All you might have to have done to get 120VAC power for lights or heat tape was come off one side of the 240 (either side) L1 or L2 and return the common to the earth ground via a ground stake, if the main breaker box was grounded to earth ground. I often check this with a meter, to be sure, otherwise I'll run a single copper ground back to the main meter box. As you know, 240VAC works by having two 120 VAC leads which are 90 degrees out of sync, one on each side of the circuit, and a neutral third lead or, (a cheapskate method of just using a 2 wire power cable to the well pump) to check out what I said, by using your multimeter (300 AC Volts position) red lead on L1 120V, black lead on L3 Neut. and it will read 120VAC, red lead on L2 and black lead on L3 neut and read 120VAC...Now! red lead on L1 and Black lead on L2 and read 240 VAC. On a normal house main breaker box the three inputs from the meter are L1 120VAC, L2 120VAC, L3 neutral, sometimes earth ground, but not too good, I like to use 3 insulated and a seperate earth ground (connected to a driven copper ground stake) Also on the bus bar where your breakers plug in each bar is connected and alternates from L1,L2,L1,L2,L1,L2 from top to bottom. notice that a 120V (single)breaker contacts only one bar and a 240 Volt breaker (double breaker)contacts two adjacent bars giving you 240 volts.

The breaker box will also have two other contact busses, one is a common for the common leads of your 120 VAC leads and a ground buss for the green 120V ground leads, many electricians connect the two bus bars together making the common and earth ground leads the same potential.
Note! I am not a professional Union Electrician! and you may want to consult a Professional Electrician about what I have posted.

 

[mikey111k]

Thanks for the input.

McDowell - Thanks for the diagram. I think i understand what your saying and it looks like it will save on a junction box and some wire.

Buzz4041 - If i understand correctly i need to have GFCI outlets in the garage. My plan was to have a GFCI on the first outlet then all the other outlets in that line would be protected. Maybe i'm wrong about the need for a GFCI all together.

Michael

 

[porcupine73]

If you are putting the switch before the GFCI, I would make sure the GFCI you select does not trip when the power is removed. I have seen some types that do that, I think more as a failsafe. But that would stink having to reset the GFCI every time.

you may want to consult a Professional Electrician about what I have posted.

Yes, I agree, that would be a very good idea.

 

[Charles (in GA)]

Note! I am not a professional Union Electrician! and you may want to consult a Professional Electrician about what I have posted.

All you might have to have done to get 120VAC power for lights or heat tape was come off one side of the 240 (either side) L1 or L2 and return the common to the earth ground via a ground stake, if the main breaker box was grounded to earth ground.

That uses the ground as a neutral, and causes current flow in the ground system, a huge NO-NO in electrical work.

Charles

 

[mikey111k]

I am slightly confused on the GFCI outlet. In my diagram for branch 1 will Outlet 1 or 3 be the GFCI outlet? I assume it would be Outlet 1 (closest to the breaker).

How many outlets can be hooked up to a single GFCI outlet?

Thanks

Michael

 

[porcupine73]

GFI shown in '1st outlet position' needs to be in '3rd outlet position' (or the first outlet after the switch). Many GFCI's have subfeed lugs, so those can feed your other outlets, but you must use both the hot and neutral of the subfeed lugs on the downstream outlets. This may complicate your setup to need 4/c wire, or just run a 2/c w/gnd all the way to the box with the two outlets, then from there feed out to your outlets and lights, then you can use 2/c w/gnd for everything.

 

[Alchymist]

Note! I am not a professional Union Electrician! and you may want to consult a Professional Electrician about what I have posted.

All you might have to have done to get 120VAC power for lights or heat tape was come off one side of the 240 (either side) L1 or L2 and return the common to the earth ground via a ground stake, if the main breaker box was grounded to earth ground. I often check this with a meter, to be sure, otherwise I'll run a single copper ground back to the main meter box. As you know, 240VAC works by having two 120 VAC leads which are 90 degrees out of sync, one on each side of the circuit, and a neutral third lead or, (a cheapskate method of just using a 2 wire power cable to the well pump) to check out what I said, by using your multimeter (300 AC Volts position) red lead on L1 120V, black lead on L3 Neut. and it will read 120VAC, red lead on L2 and black lead on L3 neut and read 120VAC...Now! red lead on L1 and Black lead on L2 and read 240 VAC. On a normal house main breaker box the three inputs from the meter are L1 120VAC, L2 120VAC, L3 neutral, sometimes earth ground, but not too good, I like to use 3 insulated and a seperate earth ground (connected to a driven copper ground stake) Also on the bus bar where your breakers plug in each bar is connected and alternates from L1,L2,L1,L2,L1,L2 from top to bottom. notice that a 120V (single)breaker contacts only one bar and a 240 Volt breaker (double breaker)contacts two adjacent bars giving you 240 volts.

The breaker box will also have two other contact busses, one is a common for the common leads of your 120 VAC leads and a ground buss for the green 120V ground leads, many electricians connect the two bus bars together making the common and earth ground leads the same potential.
Note! I am not a professional Union Electrician! and you may want to consult a Professional Electrician about what I have posted.

So much wrong here I don't know where to begin.