Steve, Well stated and thank you.
Some may have the idea that I do not advocate the use of wrist straps. To
the contrary, wrist straps are an excellent device and I use one regularly
inside the case. But, I know that they do not protect me from electrical
shock, and, for that reason, I do the opposite when working around dangerous
voltages. I make sure that I am not the shortest path to ground, or even in
the path for that matter. I feel it would be a hazard to leave people
thinking that such a device strapped to their body would protect them from
all electrical shock hazards. You have made that point quite well in your
statement. That was the point that I tried to make but may have muddled it
in my short response earlier.
Thanks again Steve.
...John
----- Original Message -----
From: "Steve Collins" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, January 01, 2004 10:48 AM
Subject: Re: [PCBUILD] Grounding yourself; Was: Adding memory - grounding
yourself
> Hi Dean,
>
> After spending 20 years in the semiconductor industry (including FAB and
> Probe & Test), I think that I can consider myself a bit of an ESD expert.
>
> I think that the confusion here is being caused by the term "grounding".
In
> this case, the term is not really being used properly (or maybe it's more
> accurate to say that it is not being applied properly). Grounding is
> required when the potential of some part of an electronic or electrical
> circuit must be set at the same potential as the planet Earth. This is
> accomplished simply by connecting (or "grounding") that part of the
circuit
> or component to the planet through a conductive piece of material with a
> resistance of less than 1 ohm.
>
> When dealing with ESD, the concern is not with the grounding of any
element.
> The concern is with maintaining anything that will touch, or anything that
> will come close to each other, at the same electrostatic potential. If
you
> are grounded through a wrist strap, and your case is sitting at a
potential
> of 5KV due to electrostatic build-up, then grounding is actually a bad
thing
> since you will definitely draw an arc as soon as you get close enough to
the
> case. So, the focus here is to maintain all elements that come in contact
> at the same potential:
>
> Connect your wrist strap to the object that you are working on. In the
case
> of a computer, clip the strap to a bare piece of metal that is part of the
> case. If you have a number of objects that you are working on (e.g. a
hard
> drive that is to be mounted in the case, new memory, etc.), then place all
> objects on a conductive mat and connect your wrist strap to the mat. It
is
> NOT necessary to ground any part of this setup. Remember that the object
is
> simply to bring all elements to the same potential. We never recommend
> using any part of a live circuit (including house wiring) for any purpose
> other than providing power to an electrical instrument or appliance.
NEVER
> connect a living thing to your house wiring. This includes the cat, the
> fish, the canary and, oh yes, YOU! If you require a ground reference,
> install a separate ground bus that is not part of, or near, your house
> wiring. NEVER remove, install or replace components on a device that is
> connected to a source of power (i.e. ALWAYS unplug the power supply before
> doing any component work).
>
> Follow these simple rules and you and your components will live to see
> another day.
>
> Regards,
> Steve Collins
> AlternateRealities - High Performance Computers, Clusters and
> Infrastructures
> Phone: (819)669-8885
> Fax: (819)669-8887
> e-mail: [log in to unmask]
> URL: http://www.AlternateRealities.ca
>
>
> > -----Original Message-----
> > From: PCBUILD - Personal Computer Hardware discussion List
> > [mailto:[log in to unmask]] On Behalf Of Dean Kukral
> > Sent: Thursday, January 01, 2004 9:45 AM
> > To: [log in to unmask]
> > Subject: [PCBUILD] Grounding yourself; Was: Adding memory -
> > grounding yourself
> >
> > What if you have a faulty device in your house with a short
> > (fault) to ground? It is **possible** for the ground wire to
> > be hot, isn't it? I know it is not likely, and even if you
> > got shocked, it would not likely be serious, but for the
> > average guy who works on his computer only now and then, I
> > think that a wrist strap connected to the case is the better choice.
> > The problem is ESD. On a case with many sharp corners and
> > edges, electrostatic charge is quickly dissipated.
> >
> > Are there any electricians out there who can tell us if I am
> > being anal about this?
> >
> > Dean Kukral
>
> The NOSPIN Group is now offering Free PC Tech
> support at our newest website:
> http://freepctech.com
>
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