Tools, Sharpening and Power Machinery - Shock from hand drill

I have a 10 year old DeWalt reversible drill that gave me a couple of electric shocks through my hands while I was using it today. I took the drill apart, checked the wires and the brushes and saw nothing obvious that looked like trouble. Before I send it to be repaired, does anyone have suggestions for what I should check out and repair on my own?

Many thanks.

a couple of points

you where using a GFCI I hope I carry a portable one in the truck and use it anywhere Im using power tools that isnt protected.

you probably can buy a new cordless drill for the repair price .

if you dont see anything obvios when you take it apart then repair seems like your next step.

David,

If you checked for broken wires then the most likely origin of the current leakage would be defective motor windings within the drill and is not easily repairable.
If this is a grounded drill then either the ground prong has been broken off, the ground wire broken or the recepticle/extension cord is ungrounded.

I would first replace the drill because unless you drilled into a wire to recieve the shock the drill is at fault.
If you plugged it into a grounded recepticle I would also make sure that there is no problem with the grounding.

I'm thankful for the answers. It is not a grounded drill, but "double insulated", so it's probably the windings then. There is a Dewalt Service Center near me, so I let them give me the bad news in person.

I suppose that 10 years of fairly constant DIY use is enough to ask a hand drill.

Thanks again.

David,

The fact that this drill is double insulated would make me wonder about what happened that would allow the case to become electrically hot.

I believe double insulated to mean that in addition to the normal insulation barrier in the cord and windings that an extra separation made it near impossible for a winding short to be carried to the drill case, unless it was full of water. :confused:

Greg,

Your wondering matches the DeWalt service rep's. He said it was impossible to be shocked by the drill, no matter what. That extreme opinion aside, would the charge build up in the winding and then comes out the fan slot into my hand? The shock comes when the drill is used for an extended period, a couple of minutes or more. (I was using it to sharpen a blade.) My hand is close to the fan slot, and the windings are not far from the slot either - but I wonder if it's close enough.

I'll have the drill back in a week, and post a follow-up.

David,

When you say a charge build up, if you are referring to a static charge then no, that's not likely.

The only significance to being physically close to the windings is if there is something to carry the current over the space.
Moisture will do it but in my experience it has to be fairly wet to carry 120 volts.
I have GFCI's on plugs outside of my shop and cords can lay on the ground in a pounding rain and not trip the protector, unless a puddle drowns the end.

The only other wierd thing that can happen is if there is a lot of heat and a normally insulating material chars or burns, the carbon can and will carry current.

There's probably a simple explanation though.

you may not be feelin a shock at all. Sometime when your sharpening, metal filings get pulled into cooling fanand get expelled at high speed into your hand if its covering the slot Greg,

Your wondering matches the DeWalt service rep's. He said it was impossible to be shocked by the drill, no matter what. That extreme opinion aside, would the charge build up in the winding and then comes out the fan slot into my hand? The shock comes when the drill is used for an extended period, a couple of minutes or more. (I was using it to sharpen a blade.) My hand is close to the fan slot, and the windings are not far from the slot either - but I wonder if it's close enough.

I'll have the drill back in a week, and post a follow-up.