Junction box as first thing after service panel?

[MeentSS02]

I want to install a few new circuits in my attached three car garage w/ attic access and finished walls (sheet rock). Currently, the only outlets available are on one circuit, and that circuit is a 15 amp circuit, most of which is fed by 14-2 wire. Needless to say, it isn't sufficient even for what little I will end up doing in there (car detailing, basic maintenance, etc).

My current plan is to do a few different circuits so I can power a few things at the same time (think lights + a buffer, grinder, etc) without worrying about overloading a single circuit, but I'd like to be able to expand the circuit if I so desire. In my search of the vast interwebs, I came across a site that said that the first thing in a circuit after the connection to the service panel could not be a junction box, but I'm unsure why they said that?

I wanted to run 12-2 wire for at least one or two circuits in the six I have planned from the service panel straight into a junction box, and from there to my planned outlet(s). I know I'm making this more difficult than it needs to be, but I will probably add additional outlets once I do some work in there and figure out where else I need power, and I would rather expand the circuit from an easy to access junction box in the attic than try to fish a wire to the installed outlet.

So is a service panel -> junction box -> outlet permissible? Or should I rework this plan before I go any further?

 

[rockwithjason]

let me see if i understand you. you have a breaker panel and you want to come out of that panel into a jbox and then onto the circuit locations? I see nothing wrong with that.

 

[MeentSS02]

That is correct. The idea is that I can run the line in to the junction box, and from there drop a single line to an outlet on the wall, and continue another line to another outlet somewhere else in the garage. It is one less line to worry about fishing down through the top plate since the splices will be made in the attic and stuffed in said box. I just wasn't sure if that was legit or not.

 

[kb2tha]

Nothing wrong with that as long as the number of conductors in the junction box does not exceed the rated capacity. If so, just upsize the box or use an extension on it. Make sure to use a cover plate on the box.

 

[bczygan]

OK,
Your description below is a little hazy. Maybe because you don't have a clear idea yet about what you will need. If that is the case, then you need to sit down right now and make a list of what you will need, or might foresee needing. When you start talking about things that have motors like buffers and grinders and then throw lighting into the mix, then you need to do more than a junction box. If your main service is in or close to the garage then put breakers in and pull circuits for what you need and run each one separately. If there is a distance, then you need a subpanel. Start by making a list of each item that may be powered. Lighting should go on it's own circuit. Items with motors, depending on their starting load may also need a dedicated circuit for each one of them. There should be a general power circuit for electrical hand tools. In other words, you need a master plan. Here are some items to think about:

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.

I want to install a few new circuits in my attached three car garage w/ attic access and finished walls (sheet rock). Currently, the only outlets available are on one circuit, and that circuit is a 15 amp circuit, most of which is fed by 14-2 wire. Needless to say, it isn't sufficient even for what little I will end up doing in there (car detailing, basic maintenance, etc).

My current plan is to do a few different circuits so I can power a few things at the same time (think lights + a buffer, grinder, etc) without worrying about overloading a single circuit, but I'd like to be able to expand the circuit if I so desire. In my search of the vast interwebs, I came across a site that said that the first thing in a circuit after the connection to the service panel could not be a junction box, but I'm unsure why they said that?

I wanted to run 12-2 wire for at least one or two circuits in the six I have planned from the service panel straight into a junction box, and from there to my planned outlet(s). I know I'm making this more difficult than it needs to be, but I will probably add additional outlets once I do some work in there and figure out where else I need power, and I would rather expand the circuit from an easy to access junction box in the attic than try to fish a wire to the installed outlet.

So is a service panel -> junction box -> outlet permissible? Or should I rework this plan before I go any further?

 

[MeentSS02]

I have a pretty clear idea of what I want - I will be adding 6-7 separate circuits to power various outlets around the garage perimeter, not including extra lighting (that will be yet another circuit) or 240V for a compressor (and potentially down the road a welder). All new circuits are being wired with 12-2 NM-B. Some outlets will be mounted high for electric cord reels, some mid-level for other things, and some mounted low for when I'm working under cars. All will be protected by GFCI outlets.

The biggest thing I'm powering right now is an 8HP Master Blaster car dryer (the unit has two 4HP-rated electric motors that can be operated independently). The existing outlets in the garage can only handle one of the two 4HP motors being on at the same time, otherwise the breaker trips (not surprising since it is a 15 amp circuit). Each of the 4 walls in my garage will have new 20-amp outlets installed, and each of these will be on a separate circuit so I don't have to worry about overloading any other circuit when I'm running that dryer.

The house has 200-amp service that is accessible in the garage - the only problem is that the service panel is flush mounted with the dry wall, so fishing wire for all these new circuits will be tricky (and might involve cutting the dry wall).

 

[bczygan]

I have a pretty clear idea of what I want - I will be adding 6-7 separate circuits to power various outlets around the garage perimeter, not including extra lighting (that will be yet another circuit) or 240V for a compressor (and potentially down the road a welder). All new circuits are being wired with 12-2 NM-B. Some outlets will be mounted high for electric cord reels, some mid-level for other things, and some mounted low for when I'm working under cars. All will be protected by GFCI outlets.

The biggest thing I'm powering right now is an 8HP Master Blaster car dryer (the unit has two 4HP-rated electric motors that can be operated independently). The existing outlets in the garage can only handle one of the two 4HP motors being on at the same time, otherwise the breaker trips (not surprising since it is a 15 amp circuit). Each of the 4 walls in my garage will have new 20-amp outlets installed, and each of these will be on a separate circuit so I don't have to worry about overloading any other circuit when I'm running that dryer.

The house has 200-amp service that is accessible in the garage - the only problem is that the service panel is flush mounted with the dry wall, so fishing wire for all these new circuits will be tricky (and might involve cutting the dry wall).

First of all, you will be cutting a panel of drywall to access one side of the existing panel to remove knockouts and install fittings for the other circuits anyway, so go ahead for all of the circuits. I would install a removable panel there for future changes or additions. A junction box at the beginning of each circuit would allow for future expansion of the circuit. The JB could be in the attic if it is to remain open, or in the wall or ceiling, with a cover, if not. JB's in the middle or end of your circuit, but placed for convenient access could also be a good idea. Don't be afraid to fish, especially with an open ceiling. And don't be afraid to cut DW. It's easy to patch.

Bill

 

[MeentSS02]

I wanted the junction boxes in a couple of the circuits because I might expand them later down the road once I get other stuff in the garage (or figure out where it's going, like my garage stereo). Most circuits will be wired from the service panel straight to the first outlet, and then on down the line as needed, but I'm installing a couple that will purposely only have one outlet on them with the intent of adding more circuits later on.

I hope that makes sense - so right now, 2 of the 7 circuits I have planned will start in junction boxes...the rest will be wired normally.

 

[bczygan]

I wanted the junction boxes in a couple of the circuits because I might expand them later down the road once I get other stuff in the garage (or figure out where it's going, like my garage stereo). Most circuits will be wired from the service panel straight to the first outlet, and then on down the line as needed, but I'm installing a couple that will purposely only have one outlet on them with the intent of adding more circuits later on.

I hope that makes sense - so right now, 2 of the 7 circuits I have planned will start in junction boxes...the rest will be wired normally.

I changed my response above as I understood what you are trying to do. Yes a JB, located where you can get to it later is a good way to extend a circuit from any point where it will be covered, to an accessible place for future extension. Could be at the start, end or even come off the middle of the circuit, or all 3! You could even put a few covered ones in the ceiling, before drywalling the ceiling, to simplify future fishing.

Bill

 

[MeentSS02]

I guess I forgot to mention that the ceiling is already finished as well Thankfully, I have full attic access above the entire garage with a pull down ladder to access it, so I can hopefully fish all cables down from above to the service panel. I'll have to do some more investigating to see how far the sides of the boxes are from the adjacent studs. Considering how many knock outs aren't used on the sides, I'm guessing the studs are pretty close. The main feed line comes from the bottom, so at least I don't have to worry about getting around those things to get into the box.