Date: Fri, 16 May 2014 22:37:46 -0400
Reply-To: James <jk_eaton@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: James <jk_eaton@HOTMAIL.COM>
Subject: Re: Off topic Friday question on switches...
In-Reply-To: <5376B491.70004@gmail.com>
Content-Type: text/plain; charset="iso-8859-1"
John, that would be single phase, probably 240V (since it's South America) (or higher, then converted down to 240V), using only ground return.
While we often use a wire for ground here in North America, it's not necessary - much of the Canadian Prairies was wired initially using only ground return (a good long metal pole driven into the earth, then connected as the ground side of an electrical circuit). Many farms in rural Saskatchewan even today have their 4800V or 9600V line come to the farm as only single wire, then the power runs through a transformer on the pole to produce the conventional 240V/120V service. I have also seen the same in Central Europe, with 240 V runs of a kilometer or more after a central transformer. It certainly is cheaper than running two wires.
James
Ottawa, ON
> Date: Fri, 16 May 2014 20:00:01 -0500
> From: jrodgers113@GMAIL.COM
> Subject: Re: Off topic Friday question on switches...
> To: vanagon@GERRY.VANAGON.COM
>
> David,
>
> Sort of an aside here - I hope you can tell me.
>
> What kind of domestic power is it that is supplied to a house/shop using
> only a single wire/cable. I've never seen it done here, but in South
> America single wire power is run over great distances to meet the needs
> of remote farms while at the same time keeping costs down. Have you
> ever seen this single wire stuff??
>
> Thanks,
>
> John
>
> On 5/16/2014 6:27 PM, David Beierl wrote:
> > At 10:59 AM 5/16/2014, Don Hanson wrote:
> >> I have an induction-motored thickness planer, running on 220 single
> >> phase
> >> power...It came with a magnetic switch that has broken now 3 times and
> >> costs over $50 to replace...Hate that. I found a normal power tool
> >> switch
> >> in my box, rated for a bigger motor than this tool I am working on
> >> now...but it is a "normal" heavy duty push button power tool switch, made
> >> for 120/230 single phase or 208/230/480 three phase... This switch has
> >> four terminals on the back, two labeled "Load" and two labeled "Line"...
> >
> > Ok, what the magnetic switch gets you is that if power to the tool is
> > interrupted, the switch will disengage so that the tool won't start
> > up by itself when power is restored. I have heard it alleged, on
> > what authority I don't know, that sooner or later if you work around
> > them regularly, you'll experience a magnetic switch engaging for some
> > reason other than you deliberately pressing the button. It was in
> > context of woodworking machines. I don't have an opinion on that.
> >
> > So your conventional switch leaves you open to being surprised by a
> > tool that is still ON even though it has lost power.
> >
> >
> >> So the questions:
> >>
> >> Can I try to wire up this less expensive (and already owned) switch to
> >> make the 220 induction motor work? Right now I am using this tool,
> >> when I
> >> have to, with my power panel breaker box as the only switch....very
> >> un-safe and not at all convenient. I do need the use of this tool, but
> >> $50 a switch is now (in this tradesmen-unfriendly economic climate) not
> >> very feasible.
> >
> > If the rating is sufficient, and bearing in mind the difference in
> > operation.
> >
> >
> >> Second question: If I decide to try this hack-job, wiring for the
> >> wrong
> >> switch, how should I connect the wires? Do I take the black and white
> >> wires to the two terminals labeled "LIne" and continue on after the
> >> switch
> >> with the same colors out to the tool from the "Load" posts of the switch?
> >> Or do I just break one of the "Line" wires and use just one of the 'Line
> >> and Load" terminals, like on a house wiring switch?
> >
> > Both your wires on 220V are hot to ground, so the switch ought to
> > interrupt both of them. If you look at your breaker box you'll see
> > that the 220V breakers are actually two breakers operated by one
> > handle, to interrupt both lines.
> >
> > Yours,
> > David
> > .
> >
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