Blows a breaker, what the heck??

All it may take is holding the grinder in one hand and brushing against a grounded object (like the lathe) with your other hand, and you may be electrocuted. Proceed with upmost care.
 
Mike8623 said:
the dumore has a cord that looks like the original one 60-70 years old and it looks it.
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Replace the cord! They're not expensive.
Also, take a look at the motor. Something that old which was likely sitting around collecting dust, there could be all sorts of debris in there causing a short in the windings. Maybe blow some compressed air in there.
 
I don't agree with Hawkeye- I have never seen an appliance with one side of the power line connected directly to the case of the unit, by the factory. Even years ago they were smart enough not to do that, at least in the US
Mark
ps Can you imagine the lawsuits if there was a 50/50 chance of death every time you plugged it in?
 
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OK guys, good news. I took the entire thing apart. I blew it all out and cleaned everything I could. I taped a few wires, that couldn't be replaced and put on a new cord. I then oiled it and put a on/off switch in the cord. Plugged it in, turned on the switch and away she went, just like new, runs like a top.

I want to thank all that replied........you were a lot of help and inspiration, this is a great site, I always come here when I'm stumped, now on to grinding my cutter box for my rifling machine build.
 
Yeah, Mark. I know I wasted many years as an electrician. I only speak from experience. I try to avoid mere opinion. When I measure 90 VAC from the case of a fridge to the stove next to it, reverse the plug and measure 0 volts, I think that trumps what you have never heard about. I'm sorry I violated my own rule about not answering electrical questions.
 
Mike: Make sure that you have tested the potential between the case and a ground with a voltmeter, then reverse the plug and check it again.

Reversing the plug on a device with measurable line voltage on the case just ties the case to the neutral (and grounded side of the circuit) instead of the hot lead, covering up the issue. Plug it in backwards the next time, and the case once again will be hot.
 
Hawk: I've encountered hot chassis but it's always been due to malfunction (leakage,or a stray strand of wire touching somewhere). I've seen equipment (guitar amps, PA systems) with polarity switches that tie a cap from one side or other of the line to the chassis, for hum reduction. (also dangerous)
M
ps I believe my Dad had an old "all american 5" radio that had a hot chassis but it had a bakelite case and knobs, you weren't supposed to be able to touch the chassis during operation- I think he got shocked by it once replacing a tube :oops:
 
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What I've always found odd is that the wall receptacles, while they didn't have a ground hole, did generally have the neutral slot wider than the hot. It would have been easy to provide the cords with matching plugs, but they chose not to.
 
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