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I recently bought a single rack server, but I often get shocked when I touch the full-metal case. It seems to take 20-30 minutes to "charge" between shocks, but I'm not enthusiastic about testing that statistic further. It's connected to a properly grounded surge protector and no other objects touch it besides the wooden desk it lays on, which in turn stands on a tile floor. I assume the shock is static as I can safely touch the case after each shock. If I'm in relatively consistent contact with the case, no static charge builds. Only when it sits idle for an extended period of time do I experience these shocks. Put simply:

  1. Metal case causes regular static shocks when left untouched long enough
  2. Power Setup: server → surge protector → grounded wall outlet (indicated by the surge protector)

I know nothing about electricity, so can someone please explain possible sources of this static and potential fixes? Might my surge protector or house wiring be faulty, or is this an unavoidable feature, however unlikely? Thank you for reading.

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up vote 4 down vote accepted

Static buildup typically occurs in homes due to walking on carpets. There are spray on static treatments for carpets. Before you enter the room and touch the case, discharge the static buildup somewhere else. Screws on light switches tend to be a good place to do this.

Another way to reduce static electricity is to increase the humidity in the environment. Be careful not to exceed the manufacturers recommendations regarding humidity.

Ultimately you aren't doing any damage to anything. Discharging static on this rack before touching anything inside of it is exactly good practice. It's what I've done in every data center I've ever worked in. The reason that you don't build up a static charge while touching the rack, is because you are grounded. This is because the rack is grounded.

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You can buy anti static bands, I'm not sure if they are any good; Or a change of foot wear, or maybe a change of flooring around the machine? Any way, +1 as I didn't realize a lot of this. –  Dave Rook Jan 3 '13 at 10:06
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@DaveRook - The antistatic bands have to be connected to a source of ground (connected to a rack). A change of footwear conceivably would work, but moving through a low humidity environment will also generate a static electric charge. He said the flooring around the machine itself is tile. Once a person generates static electricity they act like a capacitor and maintain the charge. –  Everett Jan 3 '13 at 10:09
    
@Everett, Is there a reason why I seem to only get shocked by the server and not by my other computers (by touching the rear metal panels)? Is it also advisable to get an enclosure so I'm less exposed to the metal sides? –  CollinJSimpson Jan 3 '13 at 22:11
    
It's likely that the parts you are touching aren't grounded. I always leave the power cable plugged in when working on a desktop. I open the case and touch the metal frame (to discharge static electricity). Many people I know don't repair systems while they are plugged in. Some have a fear of having power turned on while working on it, I understand this. As for getting an enclosure, your option really. Again the static discharge goes straight to ground (not harming anything). If you don't do this until you stick your hand in a computer, you may do damage. –  Everett Jan 3 '13 at 23:24
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