Grounding an ESD Mat

[xebeche]

How would a service center ground an ESD mat? I need maximum protection as I will be working on other people's computers and cannot take any risks when it comes to ESD. With the mat I bought I can snap a piece onto it which serves two purposes: (1) Connect wrist band and (2) ground a metal circle at the end of a 15ft cord. How exactly should I ground?

Hang on, because this is going to get long winded... My uncle (who is an electrician, but not a computer repair man) recommends that I connect this to a 1-2ft copper rod that I drive into the ground outside a client's home. He urged me not to connect to a "ground hole" of an electrical socket. His reasoning for this is two fold: (1) That all grounds in the home would be connected and if for some reason I made a better ground than the home's ground AND there is electricity flowing through the ground then I would get a shock as well as damage the computer. (2) And there may not even be any 3-prong connections in older homes and if there is and the ground was not installed properly, or the receptacle was not actually grounded, then I wouldn't actually be grounded and would thus potentially damage the computer...

I purchased a 3M Static Dissipative Table Mat (8214) and a Wrist Strap/Table Mat Grounding System (3048) came in the box. I also just ordered a couple 3M Adjustable Wrist Strap with 5' Cord (2214). Is it all over kill? Probably, but better to be safe than sorry. I can afford the $100 now. I can't afford hundreds or thousands AND a furious client. Here's a pic:

Thanks for reading!

 

[engiNURD]

A water pipe or a sink's metal faucet is another alternative, btw. Personally, I'd make sure the client's outlet is properly grounded before plugging a computer back in, as that may be the root cause of your visit in the first place. So, ask your uncle what the optimal/practical method for testing the outlet would be; then once the outlet is tested to be properly grounded, you can use it to ground your mat. Personally, I just don't do house calls involving an ESD mat, lol. At work, we have a direct line to a copper pipe driven into the ground (at least thats what the building engineer said it was connected to, lol).

 

[Crax]

I think you'll probably be fine, but you could always buy a special smock and the special shoes if you're that worried about it.

 

[xebeche]

I've done a lot of research in the last couple days and gotten several responses from different sources. There seem to be 3 major schools of thought when it comes to ESD safety.

(1) Minimal protection is required, if any at all. Plenty of people claim to simply touch objects around them and avoid moonwalking across carpet. That is sufficient to avoid damaging computer equipment.
(2) Connecting to the ground of a receptacle is normal procedure and perfectly safe. "The ground" of a receptacle is there for a reason, right?
(3) The only safe and reliable way to ground an ESD mat, and one's self, is to pound a stake into the ground. If this isn't possible at least connect to an unpainted metal pipe or structural material that leads to the ground. Connecting to any system where there are unknowns carries a small risk, but a risk nonetheless. Even testing the ground of a receptacle may not be accurate enough as there are too many variables.

So, it seems that for the simple RAM install on a shoe string budget, the first is just fine. Typical servicing and PC building is probably well suited for the second, especially when working in the same trusted environment. Lastly, when absolute certainty is desired, connecting to unpainted metal pipes or, better yet, creating one's own ground with a stake driven into mother earth gives the greatest assurance. Anyone doing house calls or working on other people's expensive computers might be best served by considering the last option despite the extra annoyances that go into it.