A few stupid code questions

[kyle242gt]

Hi all-

My electrician buddy who's helping/advising on the side is hard to get ahold of, hope someone here can answer a few questions before I do anything else lame.

Lame? Why yes, I made about 15 very nice jumpers for grounds in my quad boxes before finding out I can only put one wire on a screw.

Here's what I've got:
15 2x4' T8s on four circuits.
That works out to less than 15A, so I can run one 15A circuit on 14/2 to the box, right?
Do I need a GFCI?

6 quads for the workbench, with a GFCI first in line on 12/2. 20A breaker, 15A outlets.
Do I need a 20A GFCI? Are 11 duplex receptacles in a row okay?

Second circuit is working out to about 4 duplex and 9 quads. Same drill, 20A breaker, 15A circuits.
Can I run that many outlets (22!) on one circuit off one GFCI? Most of these outlets will probably never get used, not that it matters...
One of these is for the garage door opener, should that be pre- or post- GFCI?

I'm in California, and didn't see any mentions of this stuff in the local code. NEC is a little overwhelming for a layman.

I have yet to run the feeds from the box, so now's the time to plan the layout. Lots of room in the panel, lots of open breakers.

 

[nehog]

Hi all-

My electrician buddy who's helping/advising on the side is hard to get ahold of, hope someone here can answer a few questions before I do anything else lame.

Lame? Why yes, I made about 15 very nice jumpers for grounds in my quad boxes before finding out I can only put one wire on a screw.

I'm a little confused, but that's normal with me...

Here's what I've got:
15 2x4' T8s on four circuits.
That works out to less than 15A,

Assuming the balasts or lamp specification says so, yes. Just 2x4' T8s doesn't tell enough about how efficient they really are.

so I can run one 15A circuit on 14/2 to the box, right?

What is the total amperage draw of all the fixtures. IOW, how much less than 15 amps? You're shooting for 80% there. Personally I always run 12 and never 14, as some day you may want to add more (whatevers) to the circuit.

Do I need a GFCI?

Do not GFCI a lighting only circuit. Only GFCI outlets.

6 quads for the workbench, with a GFCI first in line on 12/2. 20A breaker, 15A outlets.
Do I need a 20A GFCI? Are 11 duplex receptacles in a row okay?

Depends on how/where the outlets are, too.. Ceiling mounted, probably no GFCI. Wall mounted, and possibly having the lights where they can be accessed by someone standing on the floor, different...

Second circuit is working out to about 4 duplex and 9 quads. Same drill, 20A breaker, 15A circuits.
Can I run that many outlets (22!) on one circuit off one GFCI? Most of these outlets will probably never get used, not that it matters...
One of these is for the garage door opener, should that be pre- or post- GFCI?

I'm in California, and didn't see any mentions of this stuff in the local code. NEC is a little overwhelming for a layman.

I have yet to run the feeds from the box, so now's the time to plan the layout. Lots of room in the panel, lots of open breakers.

I'm unclear on what you are doing exactly, maybe someone else understands better? A drawing might help as well, perhaps with an idea of ceiling heights, too?

 

[kyle242gt]

Thanks for the reply - I tend to go overboard on the text, so I kept it brief.

Outlets:
The workbench area has 6 quads at 50". I was planning to put a GFCI at the feed end of the circuit, but was worried that 11 duplex outlets in the chain were too many. (Red)

The rest of the garage has 12" height quads (green)
And two (or more, maybe) ceiling (12') mounted duplex for the GDO lights and cord reels (blue) and one for the GDOs (purple) at 8'.

I'd like to run one feed to green, blue, purple. Load on them will be minimal. But that's a damn lot of plugs, and not sure I can run that many in a chain (branch? sorry, not good with terminology).

I'd run the feed to the green near the purple, then on to the blues, branching to the greens on the other walls.

Don't know if GDO should be pre or post GFCI, I can do either way.

But if that many outlets for green, blue, purple, are too many for one circuit, I need to rethink things.

 

[pattenp]

A 15A light circuit can carry a max of 12A which is 80% of 15A or 16A which is 80% of a 20A circuit. I think you'll find you can only put 12 of the 4' 2 tube T8 fixtures on a 15A circuit. If you using outlets in the ceiling for plugging in the T8 fixtures then I believe those outlets will need to be on a GFCI if the outlets are in a garage.

 

[pattenp]

One thing is those 12" off the floor outlets have to be a minimum of 18" off the floor. All 120V outlets in a garage have to be GFCI protected.

 

[kyle242gt]

Thanks for the input - are you sure about the outlet height? I briefly dug around for that spec, and didn't see anything.

The shop lights are plug-in, but are 10-12' from the floor.

Can I run 12/2 from the panel to the switches, and then 14/2 or /3 to the light circuits?

 

[pattenp]

Someone will correct me if I'm wrong, but all 120V outlets in a garage need to be on GFCI, I don't think it matters if it's 12" or 12' off the floor.

You can run 12/2 from the panel to the switches, and then 14/2 or /3 to the light circuits but it can only be protected by a max of a 15A breaker. If you want it to be a 20A circuit then it needs be be all 12/2 or 12/3.

And I believe the 18" min off floor in a garage is correct. I'll try to look it up.

 

[pattenp]

I can't find the 18" min height for outlets in a garage. I must have dreamed that up. But my memory tells me it was because of the possible gas vapor ignition when plugging something in.

2011 NEC all 15A and 20A 125V single phase outlets in a garage need to be on a GFCI. No exceptions.

 

[kyle242gt]

Good deal. Not what I wanted to hear, but that's okay, better from you than the inspector.

Sounds like there's no limit on the number of downstream outlets, which is nice.

 

[pattenp]

There is a code section on calculating receptacles. And again this is based on my understanding and may not be totally correct. On a 15A circuit you should not have more than 10 outlets and 13 to 14 on a 20A circuit. If I understand the calculation correctly it's amps*volts/180. So 15A*120V/180=10 and 20A*120V/180=13.333. It's most likely not this simple and may be one of the electrical gurus will chime in.

 

[BigJohn20]

There is a code section on calculating receptacles. And again this is based on my understanding and may not be totally correct. On a 15A circuit you should not have more than 10 outlets and 13 to 14 on a 20A circuit. If I understand the calculation correctly it's amps*volts/180. So 15A*120V/180=10 and 20A*120V/180=13.333. It's most likely not this simple and may be one of the electrical gurus will chime in.

Does not apply at all to a residence, and you only use this for load calculation/# of circuits.

Also, there is no minimum height requirement for a residence. You have ADA requirements (not applicable to residence) and the NECA-1 standards (not enforceable).

 

[kyle242gt]

Ran across the above items googling aboot, and found a great ******* match:
http://www.electriciantalk.com/f2/max-number-receptacles-gfi-protected-circuit-5868/index3/

 

[pattenp]

Ran across the above items googling aboot, and found a great ******* match:
http://www.electriciantalk.com/f2/max-number-receptacles-gfi-protected-circuit-5868/index3/

Forget what I said. I have no clue as to how many outlets can be on a circuit.

 

[kyle242gt]

Funny thing is, my electrical friend said something similar. I think it's either old code, or a rule of thumb, or commercial installs, or something else along those lines.

Hence my confusion!

 

[BigJohn20]

Funny thing is, my electrical friend said something similar. I think it's either old code, or a rule of thumb, or commercial installs, or something else along those lines.

Hence my confusion!

Talk to your town or AHJ (Authority Having Jurisdiction). The NEC may not even be adopted by your local AHJ. Additionally, the AHJ can revise, change, omit, or supplement whatever they see fit.

There are tons of best practices, opinions, and lore that are cited very often as code.

 

[kyle242gt]

Left a message "to be promptly returned within one business day" and never heard back from them... and I even called between 10 and 2 M-Th except for between 12 and 1 and days that have temperatures above 60F.

I read their guidelines, and other than stuff about kitchen outlets and so on, no mention of anything. http://www.sonoma-county.org/prmd/docs/rcm/rcm_sec17.pdf

 

[Norcal]

CA has been on the 2008 NEC since Jan. 2011.

 

[bjcouche]

My opinion is that 13-14 outlets on a 20A breaker isn't code in your case but it is still good practice to follow. You never know when you'll need to plug more things in and have them operating at the same time. My recommendation is to run two separate circuits, especially for your "quads" ( 2 duplex outlets in 1 box). Thus you would have in one quad box two duplex outlet's each off different breakers. I wired every quad box in my garage this way and I love it. I placed a label on the outlet plate above each outlet indicating which breaker it was wired to. That way when I go to plug stuff in, I know how much is on each circuit. A prime example is when I'm operating a 2hp router and want to also run my shop vac simultaneously. From the same quad box location I have access to two circuits so I can plug the shop vac into one and the router into the other. Plug them into the same one and the breaker trips.
Also on your GFI questions, a 15A GFI is usually rated for 20A pass through so you can put a 15A GFI outlet on a 20A circuit. One gotcha on the 2011NEC is that all GFI outlets need to be accessible. Since your garage door opener also by code needs to be GFI protected, you have two choices, use a GFI outlet in an accessible location prior to going to the outlet on the ceiling, or use a GFI breaker. You can't place a GFI outlet on the ceiling. My preference would be to have a GDO on a dedicated circuit although the pocketbook would hurt buying the GFI breaker.
You didn't mention if you have a subpanel in your garage or are wiring everything from the house panel?

Brian

 

[bjcouche]

I just read through the PDF that you linked to for your county and it reminded me that I forgot to warn you to buy the tamper resistant duplex outlets instead of the normal ones. Your county requires them along with the 2008 code for every outlet without exception. This means your outlet cost changed from $0.50 to $1.00 per outlet. This also means your GFI outlets heed to be tamper resistant too. I've heard the 2011 code makes a couple exceptions for allowing non tamper resistant outlets in non accessible locations but your county does not. Lots of folks have to swap their outlets out as soon as the inspector arrives, or was that as soon as the inspector leaves? Thought I would save you the hassle of learning the hard way.

Brian

 

[kyle242gt]

oh the hard way, man I learn everything like that.

!#$%@ at this point, I'd be money ahead hiring it out (pro's in the audience, I can hear you cheering!).

My friend quoted the 10-15 length as well, but when challenged for a cite came up empty. On the up side, he said local inspectors haven't been worrying about the tamper resistant outlets. We'll see, I already have four boxes of them installed. What? I was supposed to call for a rough-in inspection first? How was I supposed to know that? What? Hire a pro? Madness.

Thought about the dual-circuit quads, but abandoned that for simplicity's sake. I have a different circuit in the old garage with the heavy draw tools. The new shop will have stereo, computer, soldering iron, dremel, battery chargers, etc....

I think at this point I'll leave things as they are, finish rough-in, and get the inspection process started.

Wish me luck. Man, all I wanted was a place to park my cars.

 

[Charles (in GA)]

Regarding the number of receptacles per outlet, code actually does not specify at all for residential, however it does specify for commercial, you use 180VA per "yoke" as a calculation point, and on a 20a breaker, 12 ga wire, 120v circuit, this comes out to 13 "yokes", which according to code can include up to three receptacles per yoke (the common duplex receptacle not even meeting this max) The specific code section is 220.14(L)

(L) Other Outlets. Other outlets not covered in 220.14(A)
through (K) shall be calculated based on 180 volt-amperes
per outlet.

(J) actually covers residential but expects you to do a load calculation, including them in the "general lighting load calculations"

One could probably argue that (L) above is more suited to a garage than including receptacles in the general lighting load calculations.

Charles