Date: Fri, 16 May 2014 15:42:31 -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: <CANp2e0icpU4xaaFF+ibCWcf-=Ue2UyJp1iqJa6V4NaJbBEKKDg@mail.gmail.com>
Content-Type: text/plain; charset="iso-8859-1"
Unless his '220 volt, single phase' induction motor is European - German, say - where 220/240V is single phase and the two/three phase power is 480V!
I occasionally see 'misplaced' European motors here in Canada. They can be wired to work correctly, but often they are not.
The rest of your description of the wiring and start-up of induction motors is quite useful.
James
Ottawa, ON
> Date: Fri, 16 May 2014 10:03:37 -0600
> From: gnarlodious@GMAIL.COM
> Subject: Re: Off topic Friday question on switches...
> To: vanagon@GERRY.VANAGON.COM
>
> I realize this is somewhat abstract terminology. There is no such thing as 220
> single phase. 220 is 2-phase, always. 110 is nominally single phase, and
> 220 is 2-phase.
>
> 120 is single phase, "120/230 single phase" is a nonsensical statement.
>
> From the sound of your questions you may have wrongly wired a 2-phase
> relay. Each phase must be switched through separate contacts to properly
> suppress arcing when making contact.
>
> I'm not an expert, and I don't know what broke in your switch, but I
> suspect your motor is the type that starts up on a low voltage and when
> spinning switches over to high voltage. This is normally called a wye-delta
> hookup. If you have wired it wrongly to start up on high voltage it can be
> bad for your neighborhood, your workshop, your switch and your motor.
>
> In this scenario, the switch has a timer that spins up your motor, waits a
> short amount of time, then switches to a higher voltage by adjusting which
> phase hits the motor. A 3-phase motor would have 6 terminals running to the
> switch, that is why the switch is so expensive. This wiring setup is used
> on loaded (clutchless) machinery where the motor must slowly spin up some
> mass using a lower voltage. Since an induction motor pulls infinite current
> when not spinning, the wye-delta switch limits startup current until the
> motor and load are spinning fast enough to protect your wiring and the
> power company.
>
> If you are chronically running induction motors wrongly wired you may
> receive a friendly visit from the power company inquiring as to why your
> workshop is degrading their "Power Factor". In order for the wires to
> deliver quality power all three phases must be aligned properly to carry
> equal voltage and current throughout their phase. Any disruption of this
> relationship degrades the Power Factor.
>
> In the third world people commonly take out the wye-delta switch and
> substitute a plain switch, resulting in poor quality electricity and many
> problems throughout the system.
>
> -- Gnarlie
>
>
>
> On Fri, May 16, 2014 at 8:59 AM, Don Hanson <dhanson928@gmail.com> 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"...
> >
> > 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.
> >
> > 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?
> >
> > I know this is sketchy stuff but it's really tough for a working man in
> > the building trades now a days so I can't afford to do it right always when
> > it comes to my own tools and expenses..I tried Goggling "induction motor
> > wiring" etc etc...but I can't understand the wiring diagrams I get back...
> >
> > Respond off the list if you think you may be able to advise, and thanks
> > Don Hanson
> >
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