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Need a wiring diagram

66K views 47 replies 15 participants last post by  Still_Learning 
#1 ·
Ok so is this possible? I have a 3 gang box... I have one power supply coming in that needs to run 3 switches and a receptacle...

Switch 1 controls the overhead light

Switch 2 controls the exhaust fan

Switch 3 controls the vanity lighting

The catch is I would like switch 1 and switch two to be run to the light and the fan in series together (only one wire rather than running a wire from each switch to each device) I have a feeling it can be done but my question is how? 3 wire likely comes into play somewhere I am just unsure as to where.

Can someone hook me up with a wiring diagram of what is required please?


Here is a graphical representation of what I mean

Hey I am new here and this is my first thread. I have a good idea how this should be done but I just need confirmation that it can be before I ask my contractor to do it and have him look at me like an idiot...

I want a 3 gang box in my bathroom... In the gang box itself I want 3 switches... One to control my overhead light, one for my exhaust fan and one for my vanity lights... off of that I am running a standard receptacle... the catch is i want only one wire run from the gang box to the over head light and exhaust fan... here is how i want it to work out... i just need confirmation it can be done and a diagram to show me how if possible... thanks alot

 
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#6 ·
I can't make drawings but I can write.
Run a three wire cable+grd to each fan/light from the switch boxes.
Take the power in black wire and connect three short balck wires to it with a wire nut. Connect one of these pigtails to each switch.
Connect al the white wire together.
Connect all the ground wires together and to the switches if they have green ground screws.
Connect the black wire from the cable to one switch.
Connect the red wire from the same to the other switch.
Repeat for as many fan/light you have.
At the fan
Connect the black wire fro the cable to the black wire (fan)on the fan.
Connect the red from the cable to the blue wire(light) on the fan.Connect The white from the cable to the white from the fan.
 
#9 · (Edited)
I take it the fan and the overhead light are not the same unit and are seperated by some distance? If so and your diagram seems to suggest it, then do exactly as Joe or 221 said run a 2 wire with ground from the light to the fan and connect the red of the three wire cable coming from the switch box to the black in the cable to the fan the white of that cable to the other whites at the fan black to black white to white and ground it.

If this is new bathroom a 20 amp branch circuit is required for the bath and gfci for the receptacle this circuit cannot supply anything else but this bathroom.
 
#10 · (Edited)
This is what I believe you want. Click the image to enlarge. I would also suggest you use push connectors at the switch box for the grounds and hots and neutrals. This many wires going into the wirenuts is not easily done by someone not doing this everyday.
 

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#12 ·
Thanks Stubbie I appreciate it... It is pretty much what I was thinking except I wasnt sure where the red from the three wire came into play... seeing it clears everything up...

Also I ground everything in the box so that takes some of the wires out of play for me... I will take the push connectors suggestion too...

Also as Silk asked what program did you use or are you just a perfectionist at MS paint lol
 
#14 · (Edited)
1. Yes there is a limit by code, must be used as listed.

110.3(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

2. Yes, you must calculate the box fill.

314.16(B) Box Fill Calculations. The volumes in paragraphs 314.16(B)(1) through (B)(5), as applicable, shall be added together. No allowance shall be required for small fittings such as locknuts and bushings.
(1) Conductor Fill. Each conductor that originates outside the box and terminates or is spliced within the box shall be counted once, and each conductor that passes through the box without splice or termination shall be counted once. Each loop or coil of unbroken conductor not less than twice the minimum length required for free conductors in 300.14 shall be counted twice. The conductor fill shall be calculated using Table 314.16(B). A conductor, no part of which leaves the box, shall not be counted.
Exception: An equipment grounding conductor or conductors or not over four fixture wires smaller than 14 AWG, or both, shall be permitted to be omitted from the calculations where they enter a box from a domed luminaire or similar canopy and terminate within that box.
(2) Clamp Fill. Where one or more internal cable clamps, whether factory or field supplied, are present in the box, a single volume allowance in accordance with Table 314.16(B) shall be made based on the largest conductor present in the box. No allowance shall be required for a cable connector with its clamping mechanism outside the box.
(3) Support Fittings Fill. Where one or more luminaire studs or hickeys are present in the box, a single volume allowance in accordance with Table 314.16(B) shall be made for each type of fitting based on the largest conductor present in the box.
(4) Device or Equipment Fill. For each yoke or strap containing one or more devices or equipment, a double volume allowance in accordance with Table 314.16(B) shall be made for each yoke or strap based on the largest conductor connected to a device(s) or equipment supported by that yoke or strap. A device or utilization equipment wider than a single 50 mm (2 in.) device box as described in Table 314.16(A) shall have double volume allowances provided for each gang required for mounting.

Table 314.16(B) Volume Allowance Required per Conductor
Free Space Within Box for Each Conductor
Size of Conductor (AWG) cm3 in.3
18 24.6 1.50
16 28.7 1.75
14 32.8 2.00
12 36.9 2.25
10 41.0 2.50
8 49.2 3.00
6 81.9 5.00
 
#16 ·
Also as Silk asked what program did you use or are you just a perfectionist at MS paint lol
:whistling2:

Actually I am retired and over the months I have generally drawn up 4 or 5 diagrams per week that are commonly asked for on DIY forums. I just found one that was close to what you have then quickly modified it. When I was working we had auto cad and that program software was 3 thousand bucks so.... I use paint and photo shop. There are better ways to go that aren't too terrible expensive I just haven't spent the time to research that software yet.
 
#18 ·
It would be fine to do that but it always depends in old construction where power is easiest to access and the route you must take to get there. If this is new construction with open walls then yes I would say routing power to the receptacle then to the switches is fine but other than having one two wire cable less in the switch box it makes little difference.
 
#20 ·
Ok so is this possible? I have a 3 gang box... I have one power supply coming in that needs to run 3 switches and a receptacle...
Inphase277

I might mention that based on the above and post #9 ... I considered the bathroom new construction or a complete remodel. The op isn't clear on it but he makes no mention that it is not anything else. Based on this it is not a violation of 210.11 (C)(3). Please explain your reasoning.

Also... how is the gfci a probem?
 
#21 ·
I was just saying that if it were a remodel...

But 210.11(C)(3) says that a 20 A circuit shall be provided for the bathroom receptacle outlet(s), and that no other outlets can be served from this circuit. This means that the GFCI is required to have it's own circuit, and that the lights cannot be on that circuit.

The problem is that if you plug in the hair dryer, and the circuit trips, you are standing there in the dark, naked and wet:eek:!

InPhase277
 
#22 ·
A single 20 amp circuit serving a single bathroom is allowed to serve anything in that bathroom including the receptacles. The only requirement is that it cannot leave the bathroom to serve anything else. Also those things served by that single 20 amp branch circuit other than the receptacles cannot supply a total load that would violate 210.23 (A)(2). Those things considered he is compliant with current code requirements.

Exception: Where the 20A circuit supplies only a single bathroom, it can supply power to outlets for other equipment within the same bathroom, such as lighting outlets or an exhaust fan. In that case, follow the requirements of 210.23(A)(1) and (A)(2) for circuit loading.

If the gfci is located as shown it will be wired to the line terminals and will only lose power to the gfci not the rest of the circuit.
 
#24 ·
I disagree but it isn't worth arguing over. The exception you cite is to refer you to the requirements of 210.(C)(3) where it gives you the single bathroom exception telling you the other utilization equipment must comply with 210.23(A)(1) and (2). It's rather clear to me and and your going to have to change thousands of new construction bathrooms it your right. Cause this exception is a common practice in the field.
 
#25 ·
Of course it is worth arguing over! That's most of the fun. Sometimes we learn something.

210.23(A)(1) is for cord and plug connected equipment, which we know is not lighting.

210.23(A)(2) is for utilization equipment fastened in place, that is, in this instance, something like a hand dryer or wall mounted hair dryer. The mention of lighting fixtures in that section is a generalization for branch circuits.

I have never ever seen a bathroom GFCI circuit supply lighting in a new installation. It may be one thing to sneak power to a GFCI where there previously wasn't any, or to sneak power for something else from a GFCI in a remodel, but I don't know any electrician worth his salt that would, in a new residence, pull the lighting off the GFCI circuit. I think you are taking reading the code wrong in this instance, which isn't hard to do by any means.

InPhase277
 
#26 ·
OK, I dozed a bit, and woke up to that stupid infomercial about 60's music...

But anyhow, with a little more clarity now, I guess you are right as far as it goes for a single bathroom. At least that's how the code reads.

Having said that, I still don't know a single electrician who would do that. Even putting GFCI's in different baths on a single circuit is frowned upon where I'm from. Like I said, if you plug something in, and the breaker trips, then there you are, in the dark. If you have 5 bathrooms, look in the panel and you will find 5 breakers for each GFCI. And none of those will turn the lights out..

But, you are right as far as the Code goes, I can admit when I'm wrong.

InPhase277
 
#27 · (Edited)
Well you got that part right a person darn sure can read the code wrong...:)

Well only thing I can say is which is worse having the receptacle branch circuit serve multiple bathrooms and their receptacles or one bathroom and lights? ....speaking of tripping the breaker that is.

And to this day I have never had a problem finding my way out of a bathroom with the lights out....:wink:

If an exception appears in a section of code it is permissible to use it. And if not can you explain that exception in 210.11(C)(3)??

Why the exception is valid and points you to 210.23 A1 and A2 is to alert you to the load requirements of that exception in 210.11(C)(3) in order to use it. What it is saying is that if you supply the bathroom with a single 20 amp branch circuit and elect that exception then the other lights and fans or whatever can not exceed a total combined load of 10 amps.

And as far as how a bathroom is supplied it of course depends on the bathroom. If I'm running to a small bath ..ie..one basin, one duplex, shower, toilet fan and light combo I'm darn sure not going to dedicate a 20 amp to one receptacle. I rarely ever used the multiple bathroom receptacles on one 20 amp. But I'm retired now so I won't be doing it wrong anymore.....:thumbsup:

Hey I just saw your last post and you actually had me scratchin my head a bit...no sweat I've been wrong more times than I like to remember...:thumbup: Besides having code discussions at this hour takes a lot of guts.
 
#28 · (Edited)
The illustration previously given, electrically will work but also at the same time violates NEC Code. The gfci receptacle should be on a dedicated 20 amp circuit. 210.23 A (2) allows a light/vent which is an utilization equipment fastened in place to be on the same circuit with gfci receptacle being that is not more than 50% of the circuit rating. BTW a hand held hair dryer is not considered an UFIP.
 
#29 ·
The illustration previously given, electrically will work but also at the same time violates NEC Code. The gfci receptacle should be on a dedicated 20 amp circuit.
You know, I thought so too because I never do it that way. Turns out, however, that 210.11(C)(3) Exception allows it as long as that circuit doesn't supply anything else outside that bathroom.

Still isn't a good idea in my opinion, though:wink:.

InPhase277
 
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