# An inexpensive "safety" switch for 110v tools



## hman (Feb 20, 2013)

Attached is a .pdf that describes a very simple and inexpensive "safety switch" (or switched outlet) design that can be used for 115 volt tools.  The idea is to provide a small, recessed place to turn the tool ON, and a very large, easy-to-find and easy-to-push surface with which to turn the tool OFF.

A couple of disclaimers are in order here.  First off, I'm not an electrician.  So I'm not familiar with all the myriad electrical codes that might apply.  And if you're not comfortable or competent to wire 115 volt circuits, or have any doubts at all, you should get an electrician involved!  Secondly (as has been pointed out in other forums), this switch (unlike magnetic starters) will *not* default to the OFF state if power goes down.  This means that if you don't MANUALLY turn the switch OFF, whatever is pugged into it will start up as soon a power is restored!  Third, the switch only operates on one of the wires (the "hot" side of the 115), and is NOT suited for use with higher voltages.

As always,the ultimate responsibility for safety is YOURS.  I can only offer something that I think will make it easier for you to safely operate your own tools.  I can't be there to make sure you and your electrician build, maintain and operate the switch correctly, so I'm not responsible for the results.  

That said, I've installed this kind of switch in several of my shop tools - a table saw (whose original OFF witch was small and hard to push), my band saw (original switch difficult to reach), and my 9x20 G4000 lathe (as kind of a "panic button").  All have worked well, and by making a habit of always using the safety switch for ON/OFF (rather than the original switch, if it remains on the machine), I've "trained my hand" to go to the right place if there's a problem.

NOTE TO MODERATOR - This looked like the best forum for this file.  Please feel free to move it, or ask me to do so, if I've made a mistake.

View attachment Safety Switch 512K.pdf


- hman
(John)


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## Kennyd (Feb 21, 2013)

Looks good!  I did something similar on my 220v table saw, but I used the factory switch.


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## Hawkeye (Feb 22, 2013)

I like that. Nice use of a Decora switch.


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## spikec (Feb 22, 2013)

This switch makes me wish my lathe and mill didn't already come with a similar kill switch. That looks like a fun project, I think I'll build one for my drill press - not that it needs it, I just like the design )


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## Propfool (Feb 23, 2014)

Outstanding post! Great idea presented very clearly.


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## stevecmo (Feb 23, 2014)

Nicely done!! :thumbsup:

Thanks for documenting and sharing.  I think that may get copied a few times.


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## John_Dennis (Mar 8, 2014)

That is a really clever design.  You can also get Decora switch covers in steel instead of plastic which may be easier to attach the hinge to.  

If you have a 220 machine there are Decora switches that are 2 pole for 220 appliances. They are not common and probably not available at the box store.

John


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## John Hasler (Mar 8, 2014)

A clever, elegant design.  It doesn't violate any codes that I know of.  I 'm sure it wouldn't satisfy OSHA, but then not much does.


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