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Thread: Safety switch test

  1. #1
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    Safety switch test

    I see machines sold with pushbutton switches, paddle switches and safety switches that are not. A easy test is to turn on the machine and leave it running. Then flip the breaker off, wait five seconds and flip the breaker back on.
    If the machine continues to run you do not have a safety switch with contactor or overloads to protect you or the motor. If the machine continues to coast to a stop you probably have some motor protection in the switchgear.
    Bill D.

  2. #2
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    The term "safety switch" seams vague to me. Do mean an E-stop? Or a switch that has magnetic contacts that would prevent the machine from restarting after a power interruption?
    Confidence: The feeling you experience before you fully understand the situation

  3. #3
    "safety switch' is a generic term.
    Bill's method will work for power interrupt switches like magnetic.

    For those little yellow "keys" and lockouts, they're just nonsense. They do nothing other than to let you know they're there. I know of no ono who has ever actually used one of those little plastic keys as they're intended. They break easily, get lost easily, they are just the manufacturers way of covering their backside.
    An actual metal key/switch or magnetic switch are far safer options.

    A switch lock out and a power interrupt are really two different animals and provide two different functions.

  4. #4
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    Bill, Iím sure itís a typo on your part however having motor overload protection has nothing to do with having a magnetic starter.

    Motors can have built in thermal protection, and manual motor starters can have thermal overload protection.

    That said itís nice to have a magnetic starter to eliminate auto restart after a power failure.

    Regards, Rod

  5. #5
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    Quote Originally Posted by Edward Weber View Post
    For those little yellow "keys" and lockouts, they're just nonsense. They do nothing other than to let you know they're there. I know of no ono who has ever actually used one of those little plastic keys as they're intended. They break easily, get lost easily, they are just the manufacturers way of covering their backside.
    Allow me to introduce myself. When Our children lived at home and even when our grandchildren were younger, I always removed the yellow plastic safety plug from my Table saw and Radial Arm saw. Since both of our children are adults and our grand children are all teen aged or adults, I no longer pull the yellow safety plug. I have all the original yellow plugs that came with the two saws, none have broken.
    Lee Schierer
    USNA '71
    Go Navy!

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  6. #6
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    How often has anyone had a power failure and then have a machine start up again to put them in danger? It hasn't happened to me in my 52 years of woodworking. I don't stay in the shop when power is out anyway, so not a major safety hazard to me.

  7. #7
    Quote Originally Posted by Lee Schierer View Post
    Allow me to introduce myself. When Our children lived at home and even when our grandchildren were younger, I always removed the yellow plastic safety plug from my Table saw and Radial Arm saw. Since both of our children are adults and our grand children are all teen aged or adults, I no longer pull the yellow safety plug. I have all the original yellow plugs that came with the two saws, none have broken.
    Ah children, I understand

  8. #8
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    Quote Originally Posted by Richard Coers View Post
    How often has anyone had a power failure and then have a machine start up again to put them in danger? It hasn't happened to me in my 52 years of woodworking. I don't stay in the shop when power is out anyway, so not a major safety hazard to me.
    Power failure no, but trip a circuit breaker and forget to shut off the switch and have the table saw restart when the breaker was reset. No injury but the potential is there.

  9. #9
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    I, like Lee, always removed the yellow "locks" when our children were young. I also always turned off the breakers for equipment that didn't have those little keys. If we're ever blessed with grandchildren, I'll do the same.

  10. #10
    Quote Originally Posted by Doug Garson View Post
    Power failure no, but trip a circuit breaker and forget to shut off the switch and have the table saw restart when the breaker was reset. No injury but the potential is there.
    I have had momentary (less than ten seconds) power glitches. It gets your attention.
    I have a mag power switch on my TS and RAS, the lathe VFD resets electronically, the other tools just have the little yellow (child-safety) key.

  11. #11
    What do you guys do when the power suddenly goes off? Do you climb on your table saw or grip your bandsaw blades? Do you completely lose your mind without power? Who cares if a tool suddenly starts up? You should be acting like you're tools are going to do that anyway, until you've personally verified that they're unplugged.

    Mag switches just seem like another gimmick that's sold as a way to make tools seem safer, while actually making them more dangerous. Practice good safety habits. Don't rely on doo-dads and gizmos to do the thinking for you.

  12. #12
    Quote Originally Posted by Jimmy Harris View Post
    What do you guys do when the power suddenly goes off? Do you climb on your table saw or grip your bandsaw blades? Do you completely lose your mind without power? Who cares if a tool suddenly starts up? You should be acting like you're tools are going to do that anyway, until you've personally verified that they're unplugged.

    Mag switches just seem like another gimmick that's sold as a way to make tools seem safer, while actually making them more dangerous. Practice good safety habits. Don't rely on doo-dads and gizmos to do the thinking for you.
    With all due respect, this is not personal.
    I think you're way off the mark.
    I don't know how long or what kind of machinery you've been exposed to but your answer seems a little naive IMO

    If a tool stops, fine, you're usually safe but not always.
    When the power is restored, which you don't know when that will happen, you need to have your tools and material in a safe condition.
    Switch off and nothing engaging the blade or bits. A sudden start with a blade or bit engaged in the wood can be extremely dangerous and can also damage the tool.

    Mag switches are not Doo-Dads, they are tried and true power interrupt devices.
    A tool can not be turned on until the switch gets power and then the operator intentionally presses the start button. This eliminates the dangers I mentioned above.

  13. #13
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    Quote Originally Posted by Jimmy Harris View Post
    What do you guys do when the power suddenly goes off? Do you climb on your table saw or grip your bandsaw blades? Do you completely lose your mind without power? Who cares if a tool suddenly starts up? You should be acting like you're tools are going to do that anyway, until you've personally verified that they're unplugged.

    Mag switches just seem like another gimmick that's sold as a way to make tools seem safer, while actually making them more dangerous. Practice good safety habits. Don't rely on doo-dads and gizmos to do the thinking for you.
    Jimmy, when I lose power in the shop, I lose lighting.

    I don't really want auto start on my machinery, and all of my larger machines have safety interlocks for covers and guards so they need a magnetic starter.

    I'm not really sure where your comment was headed.

    Regards, Rod.

  14. #14
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    Plugging in a machine or power tool with a manual switch in the on position will wake you up.

    I worked in a shop where there were a lot of people with 4 x 24 Porter Cable belt sanders in one department. People would lock an unplugged belt sander on, so that it would charge off the bench when someone plugged it it. Fun and games.

  15. #15
    Quote Originally Posted by Edward Weber View Post
    With all due respect, this is not personal.
    I think you're way off the mark.
    I don't know how long or what kind of machinery you've been exposed to but your answer seems a little naive IMO

    If a tool stops, fine, you're usually safe but not always.
    When the power is restored, which you don't know when that will happen, you need to have your tools and material in a safe condition.
    Switch off and nothing engaging the blade or bits. A sudden start with a blade or bit engaged in the wood can be extremely dangerous and can also damage the tool.

    Mag switches are not Doo-Dads, they are tried and true power interrupt devices.
    A tool can not be turned on until the switch gets power and then the operator intentionally presses the start button. This eliminates the dangers I mentioned above.
    I work with industrial machinery for a living and we lose power all of the time. So I have plenty of experience. When the power goes out, or anything happens that you didn't expect, you stop the machine immediately. You don't try to figure it out. You stop it before you figure out what happened or what that sound was. That's what I've always done with any power tool. You don't rely on gizmos to keep you from thinking about safety. Gizmos can and do fail. You have to always keep safety at the front of your mind. Safety is YOUR responsibility. You don't pass that off to a doo-dad or anyone else. That's how people get hurt. I know. I've seen safety devices fail and people get seriously hurt because they relied on safety devices to keep them safe instead of focus and good habits. One of them will never speak, walk, or feed or dress themselves again. That incident still haunts my dreams. You don't ever forget something like that.

    Now, I'm not saying I wouldn't buy a tool with a mag switch. It's fine if it has one. I just wouldn't treat it any differently if it had a mag switch or not. If the power goes out, I'm immediately turning the machine off so I know it's off. So the mag switch doesn't offer me anything because I'm not willing to risk my health and well being on a convenience.

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