Staggering receptacles?

[6togo]

I'm in the process of laying out receptacles in my 35x50' garage and have them spaced about 6' apart. I'm wondering if I should stagger them like a kitchen A-B-A-B? What amount of receptacles would you limit per 20A circuit in a garage with a fair amount of equipment?

 

[oldtractors]

I put 2 duplex in a box every 8'. 1 on one circuit and 1 on another. 6 separate 20 amp circuits to go around the shop.

 

[mike93lx]

How much stuff can you run at once?

A shop vac with a tool?

Quantity of tools doesn't really matter if it's a one-man shop

Having a duplex every 8' fed from 2 different circuits should do just about everything. Maybe 3 or 4 circuits for the whole shop.

 

[Jim greengo]

I usually try and use a circuit for each wall in a garage.

 

[sparky 1971]

When I wire a home shop, my own included, it's been a 20 amp 120 volt circuit per wall and spaced about 10 feet apart. Additionally I will put in dedicated circuits for equipment if the customer wants. If there is going to be a 120 volt air compressor, I will suggest a dedicated circuit for that. A table saw, miter saw, etc can only be used one at a time, but if the compressor is on, it could start at any time depending on how bad it leaks.

 

[TobeyA]

I put 2 duplex in a box every 8'. 1 on one circuit and 1 on another. 6 separate 20 amp circuits to go around the shop.

I did this also. I have 4 separate 20-amp circuits.

 

[Innovate1]

I alternated circuits. That lets you have two large loads when working in an area without long cords. Also put a few larger boxes with conduit back to the panel so I could pull in whatever might be needed down the road for larger equipment, car charger, RV hookup, etc... I also put in a cord reel high up near the center that can reach all the corners and out the OHD some. Nice thing about a cord reel is you always know where it is.

 

[Wiz02]

I put 2 duplexes every other stud bay on the wall behind the bench and every 6 feet on the other walls. I thought about alternating the circuit for the bench wall receptacles, but I ran 12 awg with a 20 amp breaker and haven't popped a breaker ever.

Of course I haven't insulated and added walls yet, so guaranteed to pop a breaker after I do.

 

[beemerphile]

I alternated mine with two circuits and a duplex every six feet. Instead of alternating circuits or using double duplex receptacles, you can split wire single duplex receptacles and have two circuits available at each receptacle. As far as how many outlets you can have on a 20A circuit, I use 80% capacity and 180VA per receptacle for general use outlets. This would allow 10 general use receptacles per 20A circuit and should work fine so long as you place dedicated circuits for high current equipment that stays plugged into the same outlet all the time.

 

[jeepxj]

alternating isnt a bad idea. i'd do 4 circuits. 2 walls of A/B. and the other 2 walls of C/D.

 

[6togo]

Looks like the long walls have 8 duplex outlets which I was thinking of doing on each circuit not staggering. This way I don't use allot more wire staggering and the biggest loads I will have on them is a tire mounter and balancer. These don't have a permanent home so they may move around but I'm not closing walls in for a while so I could drop a dedicated circuit for them once I place them. The rest of the outlets are convenience outlets.

 

[dcg9381]

I just did a 15x45' wood shop extension for dad. I did exactly what you're suggesting, staggered the 20A 120V outlets A/B all the way down.

 

[beemerphile]

On my current build, I thought it would be clean to run a multiwire branch circuit with 12/3 and split-wire all of the receptacles to have both circuits available at each. However, I would need a 2-pole 20A GFCI breaker because I couldn't use receptacle GFCI's with a shared neutral on both circuits. Also, one run of 12/3 wire is almost the same cost as two runs of 12/2. So, the economics didn't work out.

 

[6togo]

Yes and staggering them uses allot of extra wire as well. If it were one wall not too bad but 3 walls doubles the amount of Romex.

 

[kaymccampbell]

Just remember to put your lights on two separate circuits from the plugs. That way if you pop a breaker or lose a 120 leg you can still stagger out with bumping into anything.

 

[6togo]

Lights are on a separate circuit! LOL

 

[6togo]

Another question a bit off topic. I ran 12/3 wire down to my second garage from the first to control the front wall lights on a 4 way switch. Is it ok to drop to 14/3 from the junction box to the switch box and then 14/2 to the lights? I ran 12 gauge wire for line loss at 175' and the 6 lights with 15w led bulbs pull very little.

 

[mike93lx]

Another question a bit off topic. I ran 12/3 wire down to my second garage from the first to control the front wall lights on a 4 way switch. Is it ok to drop to 14/3 from the junction box to the switch box and then 14/2 to the lights? I ran 12 gauge wire for line loss at 175' and the 6 lights with 15w led bulbs pull very little.

You can use 14 as long as the breaker is 15a. If 20a, you have to keep the wire at 12

 

[6togo]

Ok the first garage is wired with 12/2-3 on 20amp breakers so I guess I will stay with 12 wire as much as it pains me!

 

[Brandon_oma#692]

10' stick of conduit then 4 outlets in a box repeated down the wall. Need to finish it.

 

[dscheidt]

I alternated mine with two circuits and a duplex every six feet. Instead of alternating circuits or using double duplex receptacles, you can split wire single duplex receptacles and have two circuits available at each receptacle.

This is more work, and doesn't save very much. You're saving maybe $3 a box, or less than $50 in a building the size of the OP's, at the cost of a couple minutes per box (I find breaking the tab on receptacles more work than wiring a second outlet). I end up with three things plugged into the same box in my garage that I'd be kicking myself for years if I cheaped out like that. My shops are wired two circuits per box, each on a duplex.

you also have to use a two pole GFCI breaker, because everything needs to be GFCI protected, and you have a shared neutral. That's a wash on price, but it's a complication.

 

[beemerphile]

I end up with three things plugged into the same box in my garage that I'd be kicking myself for years if I cheaped out like that. My shops are wired two circuits per box, each on a duplex.

Seems a bit of an overreaction for a solvable problem.

you also have to use a two pole GFCI breaker, because everything needs to be GFCI protected, and you have a shared neutral. That's a wash on price, but it's a complication.

I mentioned all of these in my post #13. I think it is a clean wiring solution but it ends up a wash and I ended up alternating single duplex outlets. I couldn't see double duplex all the way around the shop to avoid keeping a 10 foot extension cord or a multi-outlet adapter around. Most people have both. If I had a roll of 12/3 that I wasn't going to use, I'd have done it. I think you exaggerate the "complications" such as installing a 2-pole breaker and breaking tabs. I presented it as a valid alternative in case someone was interested in considering it.

EDITED TO ADD: I know this is more thought than the topic is worth, but for the heck of it, I ran out the cost and installation time of the three main alternatives being discussed. Prices were generally from the orange big box store. The basis is 12 outlet locations spaced 8 feet apart.



The Multi-wire Branch alternative provides a single duplex receptacle at each location with the top outlet on Circuit A and the lower outlet on Circuit B. The Double Duplex alternative provides two duplex receptacles in a 2-gang box at each location with one duplex outlet on circuit A and one duplex receptacle on Circuit B. The Alternated Single Duplex alternative provides a single duplex receptacle on Circuit A followed eight feet later by a single duplex receptacle on Circuit B. Everyone is free to determine which offers the utility they need for the way they use their shop. There will undoubtedly be disagreement on this, but I believe that I can install the Multi-wire option in less time than either of the other options. The elements of labor and my own time estimate break down as follows:

 

[rlitman]

How much stuff can you run at once?

A shop vac with a tool?

Quantity of tools doesn't really matter if it's a one-man shop

Having a duplex every 8' fed from 2 different circuits should do just about everything. Maybe 3 or 4 circuits for the whole shop.

That was my thinking. I have 6 circuits in my garage.
15A - lights, TV, WiFi/network, assorted low power stuff like LV exterior lighting and electronic locks
20A - freezer (yeah, I didn't need a 20A circuit here, but I did want a dedicated breaker; the existing lighting was already wired on 14AWG...)
20A - "tools" This reaches any outlet I may use a 120V power tool with, and this one circuit has suited my needs just fine
20A - "loft" This powers the GDO, but also powers outlets I plug dust collection into
30A - Compressor. I need air at the same time as my plasma cutter; nuff said.
30A - welder/tablesaw/plasma. I plug things in here as needed.

 

[vavet]

One thing I wish I'd have done - have lights on two separate circuits or at a minimum, 2 separate switch, maybe just 1 or 2 lights on one, and the rest on the other. There are times I need to run into my garage to grab a tool. I don't need to be bathed in light.

I like your idea of staggering, but it certainly does use more wire. The only time I've had a problem is running my shop vac with the table saw.

 

[Ilikeike]

I staggered ours in our old car club, club house/shop.
Blue and Black circuit (wire color), with two 20amp GFCI's in the first box next to the panel, one for each circuit.
and a 240v welder outlet on each side of the shop.

I miss that shop/kegerator

 

[SlappyWhite]

Unless you have needs for more power I would stick with the two to four 20A circuits for the 120v garage supply. Instead of alternating single outlets every six feet I might go a little longer or strategic (if you know where things will be) and run double boxes with the left outlet on one circuit and the right on the other. That takes guess work out of which outlet is which (of course you could label them or do different colours for each circuit of you space them apart). Odds are if you are running on two at the same time you will be in one location....

Assuming lighting is not on these circuits.... For the maximum number of outlets/devices it will depend on local code.... Some codes say 12 outlets max per 120v circuit (no breaker amperage consideration), others may be different. Some newer codes or newer coming codes estimate 1 amp per device (average) and 80% load on a regular breaker which gets you 16 max on a 20a.... But all this is based on your code not mine so you need to follow that, I would consider running close to permitted max in this application for convenience but not totally max (say 10 if 12 is permitted). My logic is as you use the space you may want to add one or two in specific locations.... Not very many people will say they have too many outlets in their work space, I wish I did less! Each duplex outlet is counted as 1, of course.

 

[dcg9381]

Yes and staggering them uses allot of extra wire as well. If it were one wall not too bad but 3 walls doubles the amount of Romex.

As mentioned above, you can do it with a single wire of 12/3 and a double throw 20-a breaker as the circuits are out of phase. But you can't do GFCI.

 

[beemerphile]

As mentioned above, you can do it with a single wire of 12/3 and a double throw 20-a breaker as the circuits are out of phase. But you can't do GFCI.

Problem solved.

 

[u2slow]

Not a fan of exhaustively rough-wiring a shop. Let your equipment arrangement decide what power needs to be run, and do it with surface emt.

Besides the main shop panel, I have 2 more sub panels around the shop interconnected with #6-8 awg. That way the $$$ copper gets used for other circuits too instead of standing idle until I spark up the welder.

I like the #12/3c mwbc and 4x4 boxes. No gfci doesn't bother me one bit in my own personal space. You can have circuit A or B, or a light 240v receptacle in each box.

 

[Milton Shaw]

I ran 3/4 EMT to the center of each wall, installed a 4" box with two GCFI outlets and ran 3 single duplex each direction daisy chained to the GCFI. These were not multi wire circuits with shared neutrals. The 3/4 conduit left me room to run a 240 volt circuit for 30 amp tools without going into the walls again.

 

[PhantomEB]

My old garage was done A/B/A/B and each circuit for each wall had their own 15 amp breaker.

this one, I am just gonna add on extension boxes to my current 2 outlets on each wall then run conduit to spread out the 2 to 5. I don’t use em all at any times, but I like the versatility.