12-2 or 12-3

[pitterpat]

I have some 12-3 wire left from when we ran conduit out to the 2nd garage to feed 2 circuits to that garage and when we added sub panel. NO, did not use the 12-3 to run the sub panel, just used it to rewire the 2 circuits to the garage. The sub panel my buddy wired up using #4 ga.

Anyway, getting to the point, I am wondering if I should use 12-2 to wire all the xtra outlets & switches or use up the 12-3. YES, I hate that 12-3 because it is hard to pull and bulky, but I don't really want to buy another 250' to wire the outlets but I don't think 100' of 12-2 will be enough. Here is what I will be doing so far for this 16' x 22' garage.

1. 2 outlets on both sides of the garage to plug in the 60 gal compressor (this is once I get the donor car out of this gar. I can move the compressor to the other side of the garage if I want to). 5' + 15' +16' + 5' = 41' 1 each in front and rear of yellow donor car.

2. 3 outlets for the 6-8 flouscent lights I am adding to this garage. 5'+ 15' + 8'= 28' / 5' + 10' + 8'= 23' / 5' + 5'+ 8' = 18' These will be on 3 separate switches so I can turn them on in banks. 1 outlet each in rear-center, middle-center and front-center of the garage in the ceiling to plug in the flourscents'.

3. 2 outlets on the opposite side of the garage from the breaker box. 5' + 5' + 16' + 5'= 31' / 5'+ 15'+ 16' + 5' = 41' 1 ea. front & rear of garage on that wall.

4. 2 more outlets on the same side of the garage as the the breaker box. 5' + 10' + 5' = 20 / 5' + 18' + 5' = 28' - 1 under cab in photo and 2nd further down the wall

Looks like I need about 230' of 12 ga anyway.
Can you guys think of any more outlets or switches I will need? Right now on the old circuits there are 2 outlets on the walls and I just rewired 2 other outlets to plug the gar door opener in directly and an existing flourscent light.
We put the sub panel in to power the spot welder, the compressor, mig welder and the 6-8 additional flourscent lights in this garage. The wire length's may be too much but even if I take 10% off I am still at 200'.

 

[hidollartoys]

One option is to use the 12-3 for "shared neutral" circuits.

 

[KenC]

One option is to use the 12-3 for "shared neutral" circuits.

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Yep, wire with quads instead of single gang boxes. use the 12-3 to create a multiwire branch circuit. each quad will have 2 recepts, one on each leg. To be safe, connect both hots to a 2 pole ganged breaker so if you need to work in a box, you'll know both hots aren't!

Or you can use singles with the connector broken off, but everyone needs more recepts!

 

[pattenp]

If you do a MWBC use two single pole breakers with a handle tie. DP breakers are normally common trip so if one side goes it takes out both legs. Using two single pole breakers with a handle tie allows one leg to trip without taking out the other leg, but still provides the required safety of disconnecting both legs when servicing.

 

[pitterpat]

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Yep, wire with quads instead of single gang boxes. use the 12-3 to create a multiwire branch circuit. each quad will have 2 recepts, one on each leg. To be safe, connect both hots to a 2 pole ganged breaker so if you need to work in a box, you'll know both hots aren't!

Or you can use singles with the connector broken off, but everyone needs more recepts!

Not exactly sure how to do the 1st part but that is what was done in home 2 car gar go run the 12-3 to this garage. I will take a look at it tomorrow to make sure I do it right, because under the cabinet I do plan on putting 2 - duplex recptcales there at the counter top.

Thanks!