12/3 for future upgrades and pulling 110 accessory

[macs shop]

I am getting ready to wire the workshop, and thinking of future equipment upgrades.

Currently the table saw and air compressor are 110V. I will be upgrading to a 220v saw, and could foresee a 220V compressor someday as well. So, I figure I should go ahead and run 12/3 on those 2 circuits now.

But, I am little fuzzy on how I would convert it later?

For now, I would just use the White/Black as normal, tie white to neutral bar and black to a single breaker. - and just leave the Red disconnected at either end.

Later, I purchase a 220V breaker and connect red and black wires to the breaker, and wire the plug for 2 hots and the neutral ? Is that it?

2nd related question- how do you pull 110v for an accessory off a 220V line?

example- table saw 220v line comes across the floor to the work area/assembly table. I want to put a 110V plug on the assembly table, pulling from 1 leg of the 220V. Do I just tap one hot and a neutral like any other circuit, and bond the grounds together?

 

[Norcal]

If you want 120 and 240 volts plus to comply with code requirements you would need a two pole GFCI circuit breaker, in the long term it would be better to run 120V and 240V circuits to any locations where a 240V machine is planned / desired. At this time 240V circuits do not require GFCI protection but that day is coming, so it’s not going be a big expense.

 

[Stuff]

If cord-and-plug you can install these now on a 2 pole beaker and have flexibility: https://www.homedepot.com/p/Leviton...rounding-Duplex-Outlet-Ivory-5842-I/301361341

 

[The Cobbler]

the only time you would need 3 wire is if you wanted 120/240 a the same outlets. or for split receptacles @ 120 volt.
if your plan is either 120 or 240, 2 wire is fine. neutrals aren't used in straight 240 applications

 

[sberry]

The 240 equipment may need different wire than 12. Good comps use 8 cable or 10 in pipe. Its likely the saw could use 12 but you don't know for sure? Not to be a smart azz but there is some tendency to want to use every idea we see on the net, every switch, wire configuration, every pipe fitting. Resist the urge, do it simple,,, 120V circuits, leave some means to run the right wire when needed for future equipment.

 

[strutaeng]

Why not just add circuits as the need comes? Are you going to sheetrock? Even after sheetrock you can run surface mount EMT. Perfectly fine in a shop environment.

and/or run conduit now for future circuits for your machines. Pull wire with appropriate breaker when/if time comes. No guessing.