Electrical Shock?

[Misfire]

Is it common to get an electrical shock while grinding? I know this sounds like a dumb question but if I touch a piece of steel to a running belt without any part of my body touching the grinder I get a nice static shock when I do finally touch it.

For example, if I round the end of pin stock on the slack part of the belt and then reach up to turn the machine off, I get a pretty painful static electric shock.

If I'm grinding and physically touching some part of the grinder chassis at the same time then I don't get a shock. This only happens when I touch steel to belt and then later touch the equipment.

The cord on the grinder looks factory and has a ground.

I'm no electrician but I'm thinking I have some kind of ground problem in the wiring. BUT.. since I'm new to grinding steel on a fast moving belt, I figured I'd ask here before having an electrician come out.

(We bought this house a year ago and paid extra for an electrical inspection. They gave the house a clean bill of health.)

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[Robert Washburn]

It`s called static elec. ,mine does it all the time.I`ve tried grounding my grinder and everything. Robert

[Ray Rogers]

Yes, it's very common in the winter due to the dry air and low temperatures. We had an extensive discussion on this several years back, maybe you can find that thread with the Search option. I don't remember what worked best but there were several solutions that people had come up with.

You might check your MSC Big Book (or McMaster-Carr) for anti-static products. They make rubber mats, anti-static sprays, etc that might help you. Don't wear leather soled shoes when you work, do wear cotton clothes (not nylon or polyesther). The clothing and shoes solved that problem for me.

Of course, there could be a bad ground on the machine too but if you didn't have this problem in the warmer part of the year that probably isn't the problem ....

[Rick McGee]

No different than shuffleing your feet on carpet, then touching a doorknob. I think some have tried a length of light chain attached to the grinder and the other end tucked into a pocket.

[TexasJack]

Get some antistatic spray at the store or just coat the equipment with a little bit of dishwashing soap.

Like someone else suggested, you might want to double check your ground.

[Misfire]

Thanks guys. I've actually had ESD (electro static discharge) training in the past so I'm familiar with static electricity but never experiencecd it to the degree that I am now. I can understand how and suspected that this machine and the friction on the belt could generate a large amount of static electricty but wanted to make sure that I wasn't the only one experiencing it to this degree.

Thanks for the advice!

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[ARCustomKnives]

As you suspect, it's probably just static build up. Like someone else already said, try some anti-static spray for laundry, and spray it on your belt.

That being said, you should DEFINITELY check all of your outlets and make sure they are all grounded and wired correctly regardless of past electrical inspections. Things can change over time, and good outlets can and will go bad eventually.

Outlet testers are cheap and plentiful, and better yet, they are easy to use.

Also, a 3 prong cord is by no means a guarantee of a ground. I can't tell you how many pieces of equipment I've opened up to find a ground wire cut off, hanging loose, or improperly connected. A quick check is to make sure you have continuity between the ground prong and the grinder chasis (if metal). You should be able to check this with even the most basic of electrical meters.

[ckluftinger]

Yep, that would be static. Happens to me all the time. I try to lean against the chassis of the grinder or touch it with one hand while working. I remember in the old days my physics teacher had a contraption for demonstrating the effects of static electricity which looked remarkably like a grinder: it had a resin belt with a very fine surface grit running over a brass sphere. It was hand-cranked, and had two wires going to a volt meter. It produced quite a current! If you held the wires a couple of inches apart, you could see the current arc across the points. The problem is that your belt runs over rubber or plastic wheels, which do not conduct the electric charge which builds up on your belt to ground, so you are the one accumulating the current like a battery. When you touch ground, it discharges. If you can maintain a ground, the current will flow right through you and you won't feel a thing. I remember the same physics teacher trying to demonstrate how different substances conduct electricity, including his tongue. I'm not kidding. You can imagine what happened: ZZZZAP!

[DaveL]

I got a strap which fastens to me and to the grinder and the problem was Actually just a wire with a wrist strap and the ability to attach it to a ground...

[Frank Niro]

Use some clothing anti static spray for about two seconds on the moving belt. Frank