Ghost In The Shop

[Bill Holt]

Yesterday I'm cutting up logs for bowl blanks.  Shut off the chainsaw and I hear an electric motor running. It was the TS.  I had not been within 10' of the TS and had not used the TS in several days.  It is a 12 to 15 year old Jet Super Saw and does not have a magnetic switch.  I do not believe in ghost, so what logical explanation can the brain trust here come up with?

[MauleSkinner]

I know what my wife would say if it were my table saw, but it’s probably best not to go there.

Did you have to reset a tripped circuit breaker recently?

[Alan S]

I once was working in my shop, and heard the tablesaw (an older Delta 34-444) go on.  I went over to check, and the switch was still off, but it had failed, turning on the saw.  I replaced the switch, but it was good reminder to unplug tools as I change blades.

[Bill Holt]

No, on the breaker reset.

Blade changes....oh-my-gosh!  That had not occured to me.  I always unplug first, probably the only good safty habbit I have.

The saw has seperate on/off buttons; but I suppose they are on one switch.  How would I  check the switch?

[Phil S.]

(11-22-2020, 02:52 PM)Alan S Wrote: I once was working in my shop, and heard the tablesaw (an older Delta 34-444) go on.  I went over to check, and the switch was still off, but it had failed, turning on the saw.  I replaced the switch, but it was good reminder to unplug tools as I change blades.

And lower the blade when you're done using the saw.

[TDKPE]

When in high school, I worked in a one-man cabinet shop after school for a while.  The wood shop teacher used to make those connections, and it was a good learning experience.  

The owner was changing a blade on his very vintage Unisaw (not a 4-footer, but not much newer), which had a manual motor control*, and which was still plugged in, and the motor started.  Fortunately for him, the arbor was empty as he was midway through the changeout.  Not even a scratch, but I think he needed to change his shorts.  

For the rest of the time I worked there, he unplugged that saw, and every other tool, before putting his hands into or onto the business end.

Oh, and the motor control was full of saw dust.  Being way under the table, on the cabinet, it was well out of the way.  Not that it mattered, though.

*A toggle switch with an overload heater and trip mechanism built into it.  Not common these days but very common back-when.  I still have a couple of them laying around somewhere in a box.

Edit: More common than I thought. Many manufacturers still make them. https://new.siemens.com/us/en/products/a...tches.html

[EdL]

Guess we know why industrial saftey protocol requires machines to be powered off and locked out.

Ed

[iclark]

Was the TS switch fully in the ON position when you found it on?

Chainsaws can produce a lot of acoustic energy that might vibrate some types of switches enough for the on connection to be made - might even be able to do it while pushbuttons were not pushed in.

[Bill Holt]

(11-23-2020, 01:11 AM)iclark Wrote: Was the TS switch fully in the ON position when you found it on?

Chainsaws can produce a lot of acoustic energy that might vibrate some types of switches enough for the on connection to be made - might even be able to do it while pushbuttons were not pushed in.

I cannot say, I pushed the off button and the saw went off.

I will take the switch off and check for saw dust after reading TDKPE's post.

[brianwelch]

(11-22-2020, 02:52 PM)Alan S Wrote: I once was working in my shop, and heard the tablesaw (an older Delta 34-444) go on.  I went over to check, and the switch was still off, but it had failed, turning on the saw.  I replaced the switch, but it was good reminder to unplug tools as I change blades.

Note to self...shut saw off when changing blades...
Thank you for that PSA. I have always just relied on the switch...