220v Plugs

[Jason Roehl]

220V is a long obsolete voltage in North America, replaced by 240V, and where 220V is still used it is mostly 50 hertz and a line to neutral voltage, brown is hot & blue is neutral. No 240V load requires a neutral, none whatsoever, so only 3 conductors are required, some appliances like ranges, & clothes dryers are 120/240V so 4 conductors are required. Knowing the difference is important.

More commonly, 220V/110V is obsolete nomenclature used by (usually older) folks who are referring, out of longtime habit, to their residential service that is now 240V/120V nominally. My current house is close to that. My previous house was often 250V/125V when I measured it.

[Mike Heidrick]

I use L6-30P and L6-30R for the 30amp or less 240V single phase connections in my shop. All those circuits are wired with 10ga romex in wall. I typically buy the plugs and receptacles like new in bulk from ebay.

[Steve Rozmiarek]

I use twist locs on everything because I prefer them. A push style plug that becomes partially disconnected has a higher chance of arcing, which in a dust filled shop is a particularly dangerous thing. I also much prefer the more sure grip of the longer twist lock. A local girl nearly died when she inadvertently touch both hot prongs of a partially unplugged 50 amp dryer plug. Weeks in the hospital, heart damage, seizures, etc. And last, but definitely not least, the twist loc plugs always have better construction of the terminals, strain reliefs and grommets, which makes a safe installation easier.

The absolute worst is a 30/50 amp 3 or 4 prong universal plug. Those things should be outlawed. The best in my opinion is Woodhead L16-20, or similar. Just make sure you pick 20 or 30 amp for the circuits and keep the cords consistent. The ground lug kicks out on 20 amp, in on 30 amp, so they are not interchangeable. If your feed circuit has a ground, and your machine doesn't need it, you can just use the appropriate terminals in a 4 prong plug. I suggest you plan for machines needing ground though and use 4 prong on everything.

BTW, Jason is right, normal folks use 220/240 interchangeably to describe the same thing. There is some factual basis to that, just refer to your meter and you will quickly see that the voltage isn't consistent across a couple circuits, let alone a substation or a national grid. During irrigation season here, 240 is actually something in the 215 to 245 range. That's a subject for a different day.

[roger wiegand]

I've come to find the debates about whether US power should be called 220, 230, or 240 somewhat amusing. If I measure it, especially in the summertime, I can have any (or all) of those over the course of a day. For what it's worth, the outlets I have are labeled for 250V.
Someone, somewhere may have declared a standard, but the power company delivers whatever it is able to on any given day. I'd guess it averages 232-235.

[Jim Becker]

Roger, the 250v labeled is the max voltage specification. While the power supply can vary slightly due to load conditions on the particular transformer you are fed from and sometimes beyond, "in general", service to our homes in the US (and I believe Canada) is 240v plus or minus a little bit which provides 120v to typical regular receptacles in our homes. (one side of the 240v feed to the home) I've also seen that variability, however...at our old property, there was a period of time where the feed was way off and I had to install a buck/boost transformer on my slider to get it to actually turn on when the voltage at the wall was a hair beyond the acceptable range for the electronics on the saw.

Terminology used by folks and even companies amazes me...there are so many instances in advertising and conversation where "110" and "220" is the word, despite the fact that as has been noted, the overall system has been operating at 240/120 for a very long time now. Force of habit.

Rollie, interesting about that "Twistlock" trademark. I guess it's another "Kleenex" thing...

[Tom M King]

Thomas Edison chose 110 Volts for his light bulbs. I think it was only in the 1930's before all the electric companies standardized to the higher 120/240 Volts thinking it would carry better through longer lines.

People who lived before the increase always referred to it as 110/220 and it has just carried over. I knew old electricians in the 1960's (I worked for one when I was 13 and 14 in Summers) who always called it 110 and 220 because that's what they grew up knowing.

It will require a lot of help from people calling it 120 and 240 to ever get past the 110/220 phase. Be one please. 220V is a European voltage.

[Bryan Cramer]

Thanks guys the conversation kind of got off track but some good info. As in “better” I currently have an extension cord I made to run to each machine one at a time. So running dedicated circuits and outlets are going to be a huge improvement regardless of the type. Obviously the quality of the plugs/outlets is the most important- no no name knock offs. I’m basically starting from scratch and want to do it right.

I’m working with an electrician to run the surface conduit, boxes and pull wire, he’s leaving it up to me to install the outlets and plugs I want. I’ll ask what his opinion is and post back.

[John K Jordan]

I've come to find the debates about whether US power should be called 220, 230, or 240 somewhat amusing. If I measure it, especially in the summertime, I can have any (or all) of those over the course of a day. For what it's worth, the outlets I have are labeled for 250V.
Someone, somewhere may have declared a standard, but the power company delivers whatever it is able to on any given day. I'd guess it averages 232-235.

Your power sounds good. Utility service spec is apparently +/- 5%, 228-252 volts for 240v nominal in the US.
I’m also always a little amused when this comes up, was pretty much expecting it when I posted y reply. To add to the fun every AC electric motor nameplate in my shop is marked either 115 or 230v and there’s a reason for that too.

I think the important thing in discussions is everyone understands that when people refer to 220, 230, and 240v they are all referring to the same thing. I usually try to use the same numbers as the OP (or the person I’m talking to.) I did this just a little while ago when a friend called about a problem with his hot tub heater. (we got it debugged and fixed during the call - yay!)

JKJ

[Jim Becker]

Bryan, there's no need to have dedicated circuits for machines that will never be used simultaneously...you can have multiple receptacles on a 240v machine circuit. You avoid the extra cost of the breakers as well as save on wire since there are not multiple "home runs" back to the panel. For example, in my new shop building, I have one 'general machine' circuit that covers the table saw, jointer/thicknesser combo, bandsaw and lathe. Only the DC, compressor and CNC machine have dedicated circuits. Since my 'general machine' circuit is 30 amp and uses hefty #10 wire, I use j-boxes to split out to the individual receptacle locations as it's easier to do the splices in larger j-boxes and only have one wire coming into the receptacle boxes where it's easier to make the terminations and tuck things in neatly.

[roger wiegand]

I'm well aware of that, my point was that my power company seldom delivers 240V and indeed sometimes delivers 220, so I've given up being dogmatic about calling it one thing or another (though I'll continue to say 120/240 out of habit and respect for the aspiration). You can probably search back on this forum and find posts where I corrected people. I've repented that particular bit of pedantry in the face of facts on the ground and will understand that when people say 220, 230, or 240 in the US they are all talking about the same thing.

Roger, the 250v labeled is the max voltage specification. While the power supply can vary slightly due to load conditions on the particular transformer you are fed from and sometimes beyond, "in general", service to our homes in the US (and I believe Canada) is 240v plus or minus a little bit which provides 120v to typical regular receptacles in our homes. (one side of the 240v feed to the home) I've also seen that variability, however...at our old property, there was a period of time where the feed was way off and I had to install a buck/boost transformer on my slider to get it to actually turn on when the voltage at the wall was a hair beyond the acceptable range for the electronics on the saw.

Terminology used by folks and even companies amazes me...there are so many instances in advertising and conversation where "110" and "220" is the word, despite the fact that as has been noted, the overall system has been operating at 240/120 for a very long time now. Force of habit.

Rollie, interesting about that "Twistlock" trademark. I guess it's another "Kleenex" thing...

[Jim Becker]

No disagreement, Roger. Other than the mention of hte 250v specification, I was just expanding on what you said. Sorry for any confusion.

[Charlie Velasquez]

I’m in the process of properly wiring 220v circuits and will be installing new outlets. What’s everyones opinion on the type of plug to use? Twist locks? Other options?

Thanks!

Curious…
I think North Dakota is using the 2020 revision of the NEC. Will these be gfci?

[Mike Wilkins]

I started out using the 6L-30P thinking that a heavy, locking industrial type plug would be the best heavy duty item for my machines. I have a tendency to over-think and over-build things, so I could justify to myself that these were needed. No regrets.
I even used industrial rated 110 volt switches and outlets for the same reason.

[Wes Grass]

Like Jim, I think, if it came with a molded on 220 plug I'll put in whatever receptacle it needs. My Oneida V-3000 for example. Bare cables,, twist locks of whatever series applies.

Most of the 'custom' stuff, like my foot switch for the router table, I buy an extension cord with a molded plug and cut the receptacle off. Cleaner, more respectable 'factory made' look to it.

[Patty Hann]

Bryan, there's no need to have dedicated circuits for machines that will never be used simultaneously...you can have multiple receptacles on a 240v machine circuit. You avoid the extra cost of the breakers as well as save on wire since there are not multiple "home runs" back to the panel. For example, in my new shop building, I have one 'general machine' circuit that covers the table saw, jointer/thicknesser combo, bandsaw and lathe. Only the DC, compressor and CNC machine have dedicated circuits. Since my 'general machine' circuit is 30 amp and uses hefty #10 wire, I use j-boxes to split out to the individual receptacle locations as it's easier to do the splices in larger j-boxes and only have one wire coming into the receptacle boxes where it's easier to make the terminations and tuck things in neatly.

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?