Replies

1. 
   mudman | May 17, 2004 05:48am | #1

   You can tell it is a magnetic switch if when you push the start button while the saw is unplugged there is no click or "switching" sound. If it is not a Mag switch the On/ Off action will still work. Magnetic switches are kind of complicated there is a relay that must be closed before the switch will close. I suppose if somehow the coils were energized..... I can't imagine how though. If it is a normal switch mabey the OFF button was not pressed in completely and the switch sprung back to ON.

   This is definately something scarry!

   Mike

2. 
   RickL | May 17, 2004 06:22am | #2

   If it's a 3 hp saw it should have the magnetic switch. I've seen magnetic switches that were hair trigger switches where a cart bumping up against the saw would start it. I was in one shop where you barely had to touch the switch and it would start. That's one reason I always unplug the saw when changing blades. Typically the magnetic contactor is in too close to the contacts. A friend had a saw that was the opposite. The contactor was too far to engage so I put a few layers of tape to bring it in closer and it was fine. I suggest you get another switch. Your local motor repair shop could help out. I've tried some imports from Woodworkers Supply but had some good and some bad so I stick to my local supplier. One way to tell if it's a magnetic switch is to unplug it under power then plug it back in. A standard switch will stay on and the saw will start up when plugged back in. A magnetic switch will disengage when power is lost. You could see what Delta gets for a new one or there's places like Grainger, even Grizzly has some inexpensive ones. Make sure the heaters are sized for the amps on the motor or many of the new European import switches have adjustable amp levels to work on a wider range of motors.

1. 
   emerckx | May 18, 2004 02:33am | #5

   Thanks to you and the other posters. Yes, it turns out you are right, it is the magnetic switch. I checked on the Delta replacement...$179..ouch. But not nearly as painful as an accident. I'll order one tonight. I always unplug the saw when changing blades or adjusting belts or anything remotely dangerous. Even though I never really expected this sort of thing to happen, apparently it really can. I could probably save some money with a grizzly replacement ($59) but I don't want to risk getting the wrong specs. I just hope the replacement will last at least as long as the original (8years). Thanks again.

   Mike

3. 
   hammer1 | May 17, 2004 06:28am | #3

   NEVER TRUST A SWITCH! Always unplug when changing blades and making set ups. Switches get used and do wear out, sometimes they malfunction. I had a radial arm saw that would start if the table got bumped. Lock and tag out that machine until you get a new switch.

1. 
   scooter1 | May 17, 2004 08:16pm | #4

   Ditto.

   I had a serious woodworking accident some years ago. Here are my tips, all of which will probably sound familiar:

   --Lower blade while not in use.

   --Unplug the saw while changing blades

   Regards,

   Boris

   "Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934