220v Plugs

[Jim Becker]

Jim, those 240 receptacles that are on one ckt are all mounted in the wall(s), correct?
Did you mention in a previous post that you were/are considering at some point mounting (or hanging) them overhead?

All the installed 240v receptacles for my general machine circuit are on the walls. There is the "potential" that I may need to do a drop from the ceiling once I have all the tools into the new shop building and the "game of tetris" is completed relative to where I want things to live "permanently". (there is no permanent when it comes to shop arrangement...LOL) So I have a big-butt j-box up top that I can, if necessary, tie additional connections to if they are necessary. If I do a ceiling drop, it will either be supported by uni-strut or be a strain relief configured twist lock that hangs down just beyond my standing reach. Most likely it would be the former because provisions for a dust collection drop would also be involved and that absolutely needs support for a 10' drop from the ceiling.

[Bryan Cramer]

No these circuits won’t be GFI. I’m actually only planning on only one circuit, but I do need a dedicated second circuit for my new dust collector. Once things get done I think I should post a shop renovation thread. The wiring is only part of the many improvement projects…

[Bill Dufour]

I like to use four wire outlets for 240. This gives me 120 volts at the machine for whatever. I often add a 120 outlet on the front for a drill, sander or vacuum.
Bill D

[Jim Becker]

Bill, with today's current cost for copper wire, such as 10-3, doing four wire circuits where they are not absolutely necessary really raises the budget bar. I had to do that for my CNC and that 30' of cable was "gold plated"...

[Rollie Meyers]

I like to use four wire outlets for 240. This gives me 120 volts at the machine for whatever. I often add a 120 outlet on the front for a drill, sander or vacuum.
Bill D

If it's 30A & above, just tapping for 120V is not a good idea, and if a 15A or 20A receptacle is used on a 30A circuit is a flat out code violation in most cases.

[Jason Roehl]

If it's 30A & above, just tapping for 120V is not a good idea, and if a 15A or 20A receptacle is used on a 30A circuit is a flat out code violation in most cases.

I’m not sure that’s true if the receptacle is on a plugged-in machine. It would be true if the receptacle were hard-wired to the circuit.

[John Lifer]

Bill, with today's current cost for copper wire, such as 10-3, doing four wire circuits where they are not absolutely necessary really raises the budget bar. I had to do that for my CNC and that 30' of cable was "gold plated"...

Very much agree. You would actually be cheaper running a separate 120v line where you need it and be IN code. 4 wire is expensive. Along with added cost of the outlets and plugs.
Keep the voltages separate.

And for my two saws that are 240v I just use straight plugs. Twist lock are twice as expensive and really don't help in most instances. For my two older RAS and my lathe that are running off VFD and 240v I just use again straight plugs which are easily disconnected to power down the VFD.

[Maurice Mcmurry]

Electric ranges and dryers now require a four conductor 240 V circuit. It is one of those modern "improvements". Some delicate electronic control circuits require a point of zero volts as well as a ground. So we have a big fat neutral required for a low voltage, low amps control circuit. If a stove or dyer stops working these days it is generally a problem with the electronics.

[Jack Frederick]

As to the 3 or 4 wire 240v plugs, I have a few three by each of the doors for my welder. My daughter bought a electric Q-tron Audi and we had to add a fourth wire for her charging cable. Going forward that may become more of an issue and lead one to want the four wire in places.

[Justin Rapp]

As to the 3 or 4 wire 240v plugs, I have a few three by each of the doors for my welder. My daughter bought a electric Q-tron Audi and we had to add a fourth wire for her charging cable. Going forward that may become more of an issue and lead one to want the four wire in places.

4 wire is typical only when part of the device needs a 120v power source, such as an electric appliance that runs 240v for the heat (dryer/oven) and the control panels are at 120v. I suspect the Audi charging system has 120v controls.

[Bob Borzelleri]

When I built my shop, I decided that all the 240V machines would get power from ceiling drops; maybe because it was easy to install runs through the attic.

But, the main reason was that I wanted the flexibility to use machines where I wanted to use them. Since everything is on wheels (except the lathe and cyclone dust collector that lives in it’s own room), I can use tools near the center of the shop which is my preference.

That said, all the drops are twist lock in order to overcome gravity. Most of them still actually lock.

[Cameron Wood]

This is a drop to an outlet box that feeds three 110v (yeah, whatever...) machines.
A prusik knot for strain relief and adjustability.

IMG_3803.jpeg

[Maurice Mcmurry]

I have ball end bungees with prusik knots on my over head drops too. It works well.

[Charlie Velasquez]

No these circuits won’t be GFI. I’m actually only planning on only one circuit, but I do need a dedicated second circuit for my new dust collector. Once things get done I think I should post a shop renovation thread. The wiring is only part of the many improvement projects…

You said not gfci, but you should check with the AHJ in your area.
If your locale is using 2020 NEC, you may not have a choice on 3-wire or 4-wire.

D70F940B-2B4B-4B1B-B079-4766495DCBBA.jpg

If you must indeed have a gfci circuit, I think they are only made with a neutral pigtail.

[Jim Becker]

I was thankful with my new shop building project that my jurisdiction has not adopted the 2020 NEC. Interestingly, I think that the industry sees the writing on the wall as my panel has plug-on-neutral which reduced the cost of the 120v GFCI breakers noticeably. No pigtails required. I have not checked, but hopefully, there would be 240v GFCI breakers that can also leverage that plug-on-neutral which eliminates the pigtail.