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I was wandering around the net tonight looking for nvr switch for my sawbench and found this warning about them.
I have them on most of my newer machines have them and I always thought that they were as safe as houses. It seems that I was wrong, although I have never has a machine spontaneously start on me.
http://www.waterfront-woods.com/Arti...icstarters.htm
Robert
If I want my machines off, I also turn them off via the outlet
Still, that's really dangerous......it would be more of a safety issue when working...
An NVR switch isn't magnetic like the ones talked about in that link. NVR switches are safe, and veeery annoying. As soon as I got my metal lathe I ripped the switch cover off.
I used to have a Black & Decker that would turn itself on if I left it in the sun on a hot day. Scary
That IS scary! Actually finding a B&D that would run. :rolleyes::DQuote:
Originally Posted by echnidna
It may have gotten bored waiting for you to get back to work. You should have trained it to start work without you.:p
When I underwent my basic orientation to the maintenance of stationery power tools. We were told to ALWAYS turn the power breakers to OFF on the wall. So as to forestal this exact problem. To this day, as a force of habit, I will not perform any operation on a machine unless the power breaker is OFF.
Some expensive machines have three or more switches that must be set to on before you can push the start button. Woodworking is such an inherently dangerous activity, anything that I can do to make myself saver, then all the better.
I'm with you Thumbsucker.
Is it seriously being suggested that people work on machines without the power being switched off and just relying on the actual machine switch? Crazy.Anything can happen, an accidental bump of the switch and oops no more fingers to turn it off with anyway. I go the next step and remove the lead before touching the thing, and that goes for 3 phase also.
I was also taught to buy quality, respect and care for your tools and equipment and most all treat everything with the respect it deserves, especially power tools and machines. I see too many accidents and near misses every day that come with the statement - I was in a hurry!
PEN :):)
Yes, I have seen people do it. Ooh I need to adjust this thing, they push the green button and they reach into the machine. 999/1000 times nothing happens, but I do not want to be that one out of a thousand, who gets unlucky.Quote:
Originally Posted by PEN
I kind of treat a machine like a loaded gun that has the safety off, even when I am holding the gun, I never trust the gun or the machine.
I have to agree with you Thumbsucker. About 10 or so years ago I was sitting a doctors office talking to a lady in the waiting room. She got a call from her husband telling her that he had an accident with a router. It seems that he had been changing bits and gotten the toggle switch caught in his jumper starting it and tearing the palm out of his hand. She was quite calm about it when she told me about it, then telling the girl at the desk it was not the first accident he had, had. The year before she said he had shot himself in the hand with a nail gun. ( I guess we can all have accidents) The receptionist asked what he did for a living, The lady replied he's a bulider. So its always stuck in my mind when changing bits or tools to check the power first.
How does an NVR switch work?Quote:
Originally Posted by funkychicken
Quote:
Originally Posted by funkychicken
He is talking about a No Volt Relay switch. It's, I presume, American and 10 years old and some of the terminology is different to what we would use but it is still a NVR.Quote:
Originally Posted by Jack E
When you push the start button it energises a contactor which uses one of its own contacts to keep itself energised. If you push the stop button or turn the power off the contactor drop out and wont start when the power is re-applied. The springs in a contactor are quite strong and I doubt you would be able to start the machine by hitting the casing.