Current leak?

As a second answer aside from the electric tool diagnosis, I’ve had a lot better results sharpening chisels, and axes and such with a file than by grinding. Try a 10 inch mill b-st-rd (- for a to avoid offending content filters unfamiliar with the trade name for a file with twice as many cutters per inch.)
You can use a oiled whetstone to hone the edge after its filed, but if you use the file properly you won’t need to. The file won’t heat the steel and anneal it, so the edge will last longer; and you can put an edge on a chisel sharp enough to shave with.

Oliver Street
September 2019

Mains power insulation of a motor is tested using a high voltage leak test and the test can’t be performed with a volt-ohm meter. You can unplug the tool turn the switch on and test for the resistance from mains power to frame and it should be a value higher than the meter can read. If it reads less then you have confirmation of an insulation failure, but if it reads infinite ohms that only means that an inadequate low voltage test method doesn’t detect an insulation failure. Many times failing insulation can still withstand and block low voltage and breaks down and leaks higher voltage.

If you have received a (mild) shock from a tool rest attached to the frame of a grinder’s motor, then the obvious answer is that there is a leakage path from the power line to the motor’s frame and the motor frame is not earth grounded.

It’s far from impossible for a grinder that isn’t properly grounded, especially one with a buffing wheel on one end, to build up a static electric charge. If all you felt was a static electricity discharge, earth ground the frame and use a ground fault protected outlet in case you were wrong about it being a static electric discharge.

A mains power leakage path *might* occur where the cord enters the tool, if not then it’s more likely the insulation on the motor windings is defective than something exotic about the wiring at the switch, but check it anyway, switches and wire are relatively cheap fixes. It typically isn’t cost effective to have a fractional horsepower motor re-wound. Replacing the motor or the entire tool is usually more cost effective,

Oliver Street
September 2019

I repeat: Let someone COMPETENT diagnose it.

You COULD use a test meter set for resistance ( in the megohm range) and check for conduction between the supply plug and exposed metal parts of the machine. To do it properly, however, you would need a device called a PAT tester, which measures resistance between live parts and the metalwork but applies 600V to do so properly You are welcome to buy or hire one but I believe they are pretty expensive.

Would you know how to interpret the results?

aslkjcfhashoci
May 2018

Thank you but.
Was there something you did not understand
(,*) MADE IT CLEAR WOULD NOT ATTEMPT SELF REPAIR
Why I asked was for information what would cause it to gain knowledge so repair shop couldn't stitch me up

Bobuk
May 2018

Let someone COMPETENT diagnose it.

Better that than risk your life with something you clearly do not understand.

Get an earth leakage plug fitted (by someone COMPETENT ) instead of the normal plug or get the outlet changed for one with an earth leakage trip

aslkjcfhashoci
May 2018