SUMMARY: When an ESD station is not available, what to do?

From: Chin Fang (fangchin@Stanford.EDU)
Date: Thu Mar 30 2000 - 15:11:25 CST

Dear fellow Sun Managers,

Judging from the responses that I have got so far (still coming in), this
is indeed a significant issue and some managers have carefully thought about.

Before I go on, firstly let me gratefully acknowledge the following
Sun Managers who took their time responded to my question:

David Ledger <>
Kulp, Scott (Scott)** CTR **" <>
Richard Hogg <>
Bill Fay <>
Roger Fujii <>
Brett Lymn <>
Gerhard den Hollander <>
Casper Dik <>
Viet_Q_Hoang <>
Joe Ryals <>

I am going to make my summary based primarily on Mr. Joe Ryals' and
Mr. David Ledger's feedback.

Quoted from David:

  "What matters is that no connection is exposed to an electrical
  potential that is different to the rest of the device by more than a
  certain amount. Because it's difference that matters, whether the
  device is earthed or not matters little. _You_ must be connected to



  "Having been a hardware tech for 5 years and a degree in EE. I would not
  ever work on a system that is plugged in to a 110v circuit. Having a wrist
  strap connecting you to the case will cause you and the ground (case) of
  the system to be at the same ground potential. If you feel safer with it
  plugged into the wall you can have the system plugged in when you connect
  your wrist strap to the system but I would then unplug it, you will
  definitely be at the same ground potential with the system."

I have sufficient background in physics to understand what they meant
above. So, rather than quoting literally what to do, I am going to
propose what I will be doing when our Netra T1 memory modules arrive:

(1) put a big enough (I have a 3'x3") anti-static mat on a clean
    table top. Put all memory modules on the mat too.
(2) put the Netra t1 105 on top of the table top, on top of the mat
(3) plug in the A/C cord so all static of the mat and the host goes
    to ground.
(4) I will touch the mat so that my "potential" is now the same
    as that of the host
(5) I will attach the 3M waist strap to myself and to the host.
    (I am stil having the same potential as that of the host; the
     strip should ensure so)
(6) now I will unplug the A/C power cord, to cut power completely
    of the host, and to avoid the concern that Joe raised above.
(7) work on the machine. All pieces from the host and to be added
    to the host are kept on the mat all the time.

The area where I usually work on machines is quite clean. It's
carpeted, but the carpet is of the typical office variety. I wear
cotton clothes too. Perhaps I should put something under the table
and my chair to further suppress the possibility of generating static.
Hopefully with this setup, it's safe enough.

Comments and feedbacks are welcome.


Chin Fang

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