# 3 pole 2 position switch



## metalmole (Dec 16, 2013)

OK im trying to make the most of my limited panel space. I have two machines that sit back to back and take 240v single phase of the same amp rating ( 15 amps ). Thought I would find a 3 pole 2 position switch ( on/off/on ) to switch current from one to the other while only using one 240v breaker from my panel box, the drop is already there running one machine....A friend told me I only needed a small toggle switch rated for the amps the machines would pull, ( 15 amps )   I don't think the small toggles would be up to the job... any advise?? anyone done this ??


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## pdentrem (Dec 16, 2013)

I do not know that a single switch would be the right way to do this. What you are talking about is a DPDT switch. Fairly common switch.
Pierre


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## John Hasler (Dec 16, 2013)

metalmole said:


> OK im trying to make the most of my limited panel space. I have two machines that sit back to back and take 240v single phase of the same amp rating ( 15 amps ). Thought I would find a 3 pole 2 position switch ( on/off/on ) to switch current from one to the other while only using one 240v breaker from my panel box, the drop is already there running one machine....A friend told me I only needed a small toggle switch rated for the amps the machines would pull, ( 15 amps )   I don't think the small toggles would be up to the job... any advise?? anyone done this ??


  If you never run them both at once just wire them to the same (20 amp) circuit.  In any case you don't need a three-pole switch.  No need to switch the neutral.


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## valleyboy101 (Dec 16, 2013)

I agree with John.  Just run one at a time.


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## metalmole (Dec 17, 2013)

I guess I could run everything in a small junction box....but would like to have a switch to turn off the power as one of the machines runs off a VFD...

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pdentrem said:


> I do not know that a single switch would be the right way to do this. What you are talking about is a DPDT switch. Fairly common switch.
> Pierre



Yep that's what my friend was referring to ....a small toggle switch 2 inputs and 4 outputs on/off/on, but I was looking more at the rotary switch type...


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## GK1918 (Dec 17, 2013)

metalmole said:


> I guess I could run everything in a small junction box....but would like to have a switch to turn off the power as one of the machines runs off a VFD...
> 
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> 
> ...




Just me being curious again.  two machines running at the same time and you need a switch for one or the other??

                                        Or do you have a low voltage problem?  
                                        For many many years we ran on 60amp panel.  A mill running a job, then the compressor comes on (thats
                                        two machines) thats 230vts, then the funace kicks on and lights are on. Our lites
                                        dont dim.   Worse yet with all the above running, my kid starts welding. still no change. But we do have
                                        heavy gauge wiring from the panel to service outlets.  since then we upgraded last summer to 200 amp
                                        service.  I still see no difference.  what can I say  Maybe you dont have a transformer out in front. 
                                        dont know I'm not a lineman.  All I can think of is back in the late 1950s when we got a new AO Smith
                                        225 amp arc welder, they had to put another transformer out there on the pole. just my guess

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Wait I re-read again I see limited panel,  simply add a sub panel somewhere with heavy gauge wire tapped into the main breaker.
Our panel if I remember is the main breaker goes to all the 110 breakers, the from the main goes to another 230 breaker.  so all 
230 machines come from the sub 220 sub breaker panel.   If I'm wrong , well the shop is a runnin just fine...........


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## metalmole (Dec 17, 2013)

Yea, I wont be runnin the machines at the same time, I just moved a surface grinder right behind one of my lathes that has a drop to it, just wonting to grab power from that drop instead of runnin a separate drop for the surface grinder...I found this switch on ebay....looks like it would do the trick if I decide to use a switch....


http://www.ebay.com/itm/LW28-20-2-D...135?pt=LH_DefaultDomain_0&hash=item35c90a1a0f


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## Wireaddict (Dec 20, 2013)

That 20A, 2-pole, 2-throw [or DPDT] switch is probably the best way to do what you want.  I wouldn't want to keep the VFD constantly energized either.  I'd house the switch & wiring in a small enclosure so that just the front of the switch is showing &, if you use cords or cables to the machines, use romex connectors or cord grips to protect them from chafing on the edge of the box.


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## mitsue (Dec 21, 2013)

I use "twistlock", 240 volt plugs on all my machines. Only plug one in at a time. (use a hanger to keep the plugs up near the receptacle) A plug into a receptacle acts as a disconnect for code purposes here.

Edit: Or put in two receptacle boxes and leave them both plugged in.  You might be surprised at how low the running amperage is on most machines. As hobby machines most of us rarely load them up enough to draw the amp rating the motor states. (not including startup) If the grinder is automatic you could leave it running and see if you can start and run the lathe. (breaks up grinding boredum))


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