# 220VAC vs. 240VAC Saw Motor S.O.T.

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• posted on July 1, 2010, 7:21 pm
I was asked today about a motor stamped 240VAC. I kept saying 220 volts and my neighbor would interupt and remind me it said 240 VAC.
I told hm that I didn't think it mattered and that I'd never heard an explanation of why we see stuff rated at 240 VAC when most of our homes seem to come standard with 220 VAC and 115VAC.
I've heard 120VAC bandied about and figure those two legs make up the 240VAC.
I told hime that I knew where to post this question having seen days of posts on similar Electrical (S.O.T. - somewhat off topic) posts with some folks who appeared to know their stuff providing links to references and resources.
So, if one og those folks is reading this, please respond and tell me what gives with the 220 vs. 240 VAC. Can we ignore the minor difference and usethese motors on "220" or "240?"
FYI - The motor in question did not indicate it was a dual 120/240 voltage motor - it just said 240!

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<%-name%>
• posted on July 1, 2010, 7:47 pm
On 7/01/10 3:21 PM, Hoosierpopi wrote:

Hook it up and start making sawdust, there is no problem.
--
Froz...

The system will be down for 10 days for preventive maintenance.

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<%-name%>
• posted on July 1, 2010, 8:44 pm

True.
Because our homes *don't* "come standard" with 220 and 115 VAC. It's at least 240/120 now. It never was 220/115 -- the lower voltage is always half the higher voltage. Measure what's coming in at your service entrance panel. Between the two hot legs, you'll see somewhere between 240 and 250; from either hot leg to ground, half that.

Exactly. [...]
Yes.
That means it can run only on 240VAC. Some motors can run on either voltage, but you have to change the position of a jumper wire to make the change. This one can't.

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<%-name%>
• posted on July 1, 2010, 9:04 pm
Yes. Same basic voltage, different country and/or system.
In N.America we get equipment labeled 110/220 then 115/230, 117.5 vac and now 120/240 The same thing applied to 550v 575 and now 600v industrial systems
120/240 +/-10% was always the accepted standard for utilities in the last 40 years. The 220 is a European standard, perhaps Mexico, USA, poorer and espaρa based countries.
At this point they are all interchangable, mostly. The voltage difference will only make synchronous motors draw a little less current and make the power factor worse. On a residential Whr meter this won't make any difference to the bill.
I was asked today about a motor stamped 240VAC. I kept saying 220 volts and my neighbor would interupt and remind me it said 240 VAC.
I told hm that I didn't think it mattered and that I'd never heard an explanation of why we see stuff rated at 240 VAC when most of our homes seem to come standard with 220 VAC and 115VAC.
I've heard 120VAC bandied about and figure those two legs make up the 240VAC.
I told hime that I knew where to post this question having seen days of posts on similar Electrical (S.O.T. - somewhat off topic) posts with some folks who appeared to know their stuff providing links to references and resources.
So, if one og those folks is reading this, please respond and tell me what gives with the 220 vs. 240 VAC. Can we ignore the minor difference and usethese motors on "220" or "240?"
FYI - The motor in question did not indicate it was a dual 120/240 voltage motor - it just said 240!

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<%-name%>
• posted on July 1, 2010, 9:16 pm
Hoosierpopi wrote:

...
In the US and Canada, national standards (NERC www.nerc.com) specify that the nominal voltage at the source should be 120 V +/-5%.
Historically 110, 115 and 117 volts have been used at different times and places in North America. Owing to the previous usage, main power is still sometimes spoken of as 110; however, 120 is the present nominal voltage (US).
BTW, the 110 V came from Edison; it was the compromise between the voltage at which initial light bulb filaments could be made to last sufficiently long (about 100 V) and the need for higher voltages for distribution and lower current demands. Hence, initially generation was at nominal 110V allowing for some 10 V distribution voltage drop to user.
As surmised, in the US the lower voltage is one side of the "hot" to neutral and so is, indeed, precisely one-half of the greater.
--

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<%-name%>
• posted on July 1, 2010, 10:02 pm
On Thu, 1 Jul 2010 12:21:21 -0700 (PDT), Hoosierpopi

I'll do my best to simplify the answer.
I think its time for me to explain about 240 current and why it is so different from 120 volt service. First of all, it's twice as big. Secondly, it'll shock you more. Outside of that, 240 is really two 120 volt lines coming to your house from different parts of the globe. The up and down 120 comes from the northern hemisphere, and the down and up version comes from below the equator.
Without trying to get technical, it all boils down to the direction water flows when it goes down the drain. In the top of the earth, it goes clockwise, while on the bottom of the earth it goes counter clockwise. Since most electricity is made from hydro dams, the clockwise flow gives you an up and down sine wave, while the counterclockwise version gives you a down and up sine wave. Between the two, you have 240 volts, while either individual side only gives you 120 volts.
This is particularly important to know when buying power tools -- which side of the globe did they come from? If you get an Australian saw, for instance, it will turn backwards if connected to a US generated 120 volt source. Sure, you can buy backwards blades for it, but that is an unnecessary burden. Other appliances, like toasters cannot be converted from Australian electricity to American electricity. I knew one person who bought an Australian toaster by mistake and it froze the slices of bread she put in it.
If you wire your shop with 240 and accidentally get two US-generated 120 volt lines run in by accident, you can get 240 by using a trick I learned from an old electrician. Just put each source into its own fuse box and then turn one of the boxes upside down. That'll invert one of the two up and down sine waves to down and up, giving you 240. DO NOT just turn the box sideways, since that'll give you 165 volts and you'll be limited to just using Canadian tools with it.

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<%-name%>
• posted on July 1, 2010, 10:19 pm
This is not correct.
A sideways panel will give you a cosine waveform instead of a sine wave,
Try it! It works in my chargers to desulphate my battery plates.
A leftie for Australia brought some right handed tools with him and they work just fine in N.America. His handsaw has all it's teeth forward and he can't seem to get it to work here, but the power tools are fine.
If you wire your shop with 240 and accidentally get two US-generated 120 volt lines run in by accident, you can get 240 by using a trick I learned from an old electrician. Just put each source into its own fuse box and then turn one of the boxes upside down. That'll invert one of the two up and down sine waves to down and up, giving you 240. DO NOT just turn the box sideways, since that'll give you 165 volts and you'll be limited to just using Canadian tools with it.

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• posted on July 1, 2010, 10:37 pm
"Gordon Shumway" wrote

Many years ago, I went to electronics school. The guys there would have howled at this bit of lunacy.
I am trying figure out if you are really funny or just totally disturbed. Did you write this or get it from someplace?

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<%-name%>
• posted on July 2, 2010, 1:00 am
On Thu, 1 Jul 2010 18:37:44 -0400, "Lee Michaels"

I am probably a little of both. I had this given to me about 25 years ago shortly after I was given the responsibility for the wiring on some of the wheel loaders we designed at Caterpillar. I have enjoyed sharing that lunacy with many people since then.

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<%-name%>
• posted on July 2, 2010, 2:16 am
message

Haven't you ever heard of a power inverter?
--
On most days,
its just not worth

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<%-name%>
• posted on July 2, 2010, 12:48 am

Nicely done. One mistake tho. Canadian craftsmen only use power tools to open paint cans and drive nails. Please try and keep up with the new technologies. Other than that, your right on the money.
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<%-name%>
• posted on July 2, 2010, 2:31 pm
wrote:

Finally! A use for that Craftsman router sitting on my tool shelf!
--
βThe problem with socialism is that eventually you run out of other peopleβs
money.β - Margaret Thatcher

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<%-name%>
• posted on July 3, 2010, 4:23 am
On Fri, 02 Jul 2010 00:48:20 GMT, snipped-for-privacy@mts.net wrote the following:
Gordy said:

-snippy-
You're mistaken, sir. Canuckistanis also use high-powered/high-speed routers in the kitchen for making whipped cream. Ask your local Ironmonger, David Eisan. (or googlit on the Wreck)
-- The most powerful factors in the world are clear ideas in the minds of energetic men of good will. -- J. Arthur Thomson

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<%-name%>
• posted on July 2, 2010, 9:51 am
Gordon Shumway wrote:

<snip>
Aha! This answers the original question. It addresses boxes that are mounted at a slight angle.
--
Jack Novak
Buffalo, NY - USA

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• posted on July 3, 2010, 1:59 am

Gordon, You explanation makes perfect sense but it does not explain where we would get a third pahse from if we need 3 phase power. Any ideas? Marc

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<%-name%>
• posted on July 3, 2010, 2:10 am
Simple!
You use another breaker and run it's 120v through a photocell detector like the ones used on sentinel yard lights on a farm laneway. Use the regular 240 volt during the day and the other 120v one through the photocell will only come on at nights, being out of phase.
wrote:

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<%-name%>
• posted on July 3, 2010, 3:11 am

Mount a 3rd breaker box on a wall that intersects with the current wall at 90 degrees.
Puckdropper
--
Never teach your apprentice everything you know.

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<%-name%>
• posted on July 3, 2010, 3:42 am
Run it through a thermostat and set it at 60 degrees.
"Puckdropper" <puckdropper(at)yahoo(dot)com> wrote in message wrote:

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<%-name%>
• posted on July 3, 2010, 5:32 am

Except that it needs to be 120 degrees. ...too hot for Canuckistanis.

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<%-name%>
• posted on July 3, 2010, 1:09 pm
wrote:

I thought it was intuitive that you would use an up and down 120 from the northern hemisphere, a down and up version from below the equator plus one more (from either hemisphere) as long as you don't activate it on a Tuesday. Does that explain it better?