• We should now be fully online following an overnight outage. Apologies for any inconvenience, we do not expect there to be any further issues.

Questions about Static Electricity

Jun 8, 2008
58
0
0
I'm getting ready to start building my new computer on Monday, and I'd like to know a bit about some concerns about static electricity and preventing static buildup. Other than using wrist straps and placing the electric components on cardboard or anti-static foam, how else could I prevent static buildup? What type of clothes should I avoid wearing? Where should I ground my anti-static wrist strap? (My house is old and doesn't have any grounding pins on any outlets) My workstation for building this PC is on a wooden table with wooden floor.
 

Blain

Lifer
Oct 9, 1999
23,643
3
81
Ground yourself to the case from time to time.
I usually touch the case before removing a part from an anti-static bag.
 

DSF

Diamond Member
Oct 6, 2007
4,902
0
71
If you're working on a wooden table and floor you should be fine. It also helps that it's the summertime, as static is typically worse in the winter.

As long as you're not rubbing your wool mittens together before you pick up parts you're ok. I imagine you'll be wearing short sleeves anyway, so any shirt is fine.
 

StinkyPinky

Diamond Member
Jul 6, 2002
6,977
1,276
126
I never used anti-static straps and I've built probably a 100 systems in my time with no problems. Just use common sense. As stated, just touch the case before touching any components and you'll be fine.
 

QuixoticOne

Golden Member
Nov 4, 2005
1,855
0
0
You are wise to be concerned.

Typical ground points are either :

a) the green wire / 3rd prong in AC outlets which you lack,

b) metal plumbing pipes in older houses that do not use plastic fittings / lengths of pipe to connect the pipes (i.e. it should be metal all the way into the earth)

c) sometimes you can find the metal BOX enclosing an particular electrical outlet or lighting fixture is grounded, even if there is a 2-prong outlet installed in the metal enclosure. Basically there would have to be a green ground wire going to ground the box/enclosure or a grounded metal conduit screwed into the enclosure to provide a ground.

d) it is possible to buy what is called a "grounding rod" at a hardware / home supply store that is a few feet long thin metal pole that you push / hammer down into soft earth just outside of your home. For a temporary interior work surface ground point you then may take a copper stranded wire such as 18Ga or thicker (such as some $10 / 50' speaker wire) and run it through the door / window / cable TV egress / whatever out to the grounding rod where the wire is affixed (hose clamp, screw down terminal, wrap & twist, whatever).

e) if the area has a metal "natural gas" pipe it is possible to ground to that; give it a scrape to get the paint / dirt / rust off before you hose clamp / clamp / whatever the wire to the outside of the pipe. Needless to say, be careful not to break the pipe.

Also
a) If you want to invest in a proper setup that you can reuse in the long term it is possible to get an anti-static work-mat for the table which includes a wire lead or attachment point for one that goes to the ground. The cushion material of these mats is generally made to be ideal for laying delicate electronic components like a motherboard on and is superior therefore to laying them directly on a hard wood table due to scratching / pressure point issues et. al.

b) if you just have anti-static foam or some anti-static bags (really not the best choice) you can, rest your components on that surface and it'll be better than nothing but you should wear a wrist strap to ground yourself and be sure to pinch / touch the "work mat" often to keep it grounded as you work.

c) If you can arrange the use of an grounded 3 prong extension cord long enough to go to a verifiably properly grounded 3 prong outlet you can just use that to plug your PC PSU into, keeping the physical I/O ON/OFF switch on the PSU OFF (if it has a switch). This grounds the case of the PSU, and through it (once it is screwed into the PC case) the PC case itself is grounded. Then you can touch the PC PSU / chassis metal framework to ground yourself, and you can use these points as points of attachment for your wrist strap, work mat strap, etc.
Be sure the PSU is OFF just GROUNDED though. Some people make a special cord for the PSU that has cut off prongs so there is no AC power connections to the PSU but the ground wire is connected for grounding-only use during working, especially for cases where the PSU has no hard OFF switch.

d) If you want to do a lot of EE / tech projects you can get a "bipolar ionizer" ion blower unit that puts out precisely equal numbers (via an internal monitoring mechanism) of positive and negative ions and blows these over your work area. Thus any accumulating charges attract the opposite polarity ion and are discharged before a harmful build up occurs. You'd use this in CONJUNCTION with an anti static grounded work mat, wrist strap, grounded anti-static floor / chair mat, and grounding heel / shoe / ankle strap in a professional grade tech environment. Never use an ordinary household ionizer ANYWHERE near technology!!! It must be an electronics anti-static purpose ion blower or nothing at all.

e) As above you can get / improvise an leg (tuck inside your sock) / foot / ankle strap that is grounded, and get an anti-static floor mat with a grounding wire attachment.

f) You can also get a "spray" or floor / desk "polish" / "carpet spray" that is slightly conductive by design and helps reduce the chance of generating static, and even can help to discharge it to ground if it has a continuously applied path to a ground. Normal furniture polish / wax is bad and makes static problems much worse than just having a bare / dirty / raw surface.

g) Typically you'd want to clip the wrist strap, and foot/ankle strap (if used), and work mat strap(s) all together to a wire going to your ground point (pipe, earth rod, junction box / grounded outlet). If you don't have a good "ground point" to clip to then clipping off to metal on the PC case / PSU such as a bare metal fan / vent grille works well and is convenient for alligator clips provided that your PSU/Case is grounded through either the PSU+AC cord or through a distinct wire affixed to it.

h) You can use lengths of overlapping aluminium foil to cover your table work area over the part you'll be using most heavily, and then just secure a ground wire to it in a way that won't tear / fall off, or rest an earthed metal PC case frame / PSU frame on the foil to provide an earthing point for it.

i) For a fairly cheap / simple setup use a wrist strap, maybe some aluminium foil on the table, ground the PC case/PSU through a modified or normal 3 prong extension cord going to a grounded 3 prong outlet, and you're all set.

j) For another fairly cheap option that is a little more direct, run a long wire down to a grounding point (appropriate pipe / outlet / ground rod) as a temporary ground point for your wrist strap / mat / case / whatever. Remove the wire when done, again, cheap speaker wire / phone wire twisted pair / whatever can work for temporary uses.

k) The main thing with ESD is to avoid unnecessary movements in badly grounded work areas. If you scuff your feet across the floor, if you get up, walk, come back, if you rub your butt / back in a chair, if you rub stuff across the table / floor, etc. you can generate a charge easily. If you have all your tools, parts right in front of you within arm's reach so you don't have to sit / stand / move much then you'll make the process much safer even with no proper ESD protection. Try to reach out and "touch" everything in various combinations at appropriate places (esd packing foam, esd bags holding the parts, bare metal areas on cases / PSU, grounding eyelets on the motherboard, et. al.) to bring it all to a common potential.

l) try to avoid handling the electronics by their flat surfaces or anywhere there is a metal contact, PCB trace, component. Handle PCBs by the edges where there are no components / metal connectors to touch. Handle the CPU by its PCB edges, never touch the bottom contact rows at all. Hold cards only by their metal bracket and an insulated spot somewhere else like on the fan shroud or edge of the PCB. etc.

 

smackguy

Member
Jun 4, 2008
89
0
0
I just touch the power supply/case to discharge myself before touching/installing a part, it works for me.
 

corkyg

Elite Member | Peripherals
Super Moderator
Mar 4, 2000
27,370
240
106
Avoiding an extensive, pedantic thesis, my rules are simple. Which ones I observe depends on the time of year. When there is humidity- there is almost no chance of static electricity. When it is cold and dry, those chances multiply.

Grabbing a grounded surface before handling components is the basic rule. In severe areas such as Alaska in January - use the grounding strap.

You can test your conditions by shuffling around and holding a finger near a ground - if static is present, you can generate a spark from your finger tip. Drives the family dog bananas. :)
 

z1ggy

Lifer
May 17, 2008
10,010
66
91
haha just hold on to your case every few mintues... Should be fine. IF you really wanna go overboard get a wrist wrap.
 

Roguestar

Diamond Member
Aug 29, 2006
6,045
0
0
Originally posted by: QuixoticOne
woooooooooooooooooooords

Looks like someone is very very cautious.

Personally I just touch a metal radiator in the house to ground myself, roll up my sleeves and keep it off the carpet. Never damaged anything when I used to work tech support, never damaged any of my own stuff.
 

QuixoticOne

Golden Member
Nov 4, 2005
1,855
0
0
It is an urban legend that you can "feel" static electricity or or feel the spark if there is enough to be dangerous to electronics. You can blow electronics out at ESD levels low enough that you'd never personally feel them.

And grabbing the PC case doesn't help to "discharge" yourself if the PC case isn't grounded directly or indirectly (to a reasonable extent). Many PC cases are mostly plastic anyway, so, again, caution is warranted.

I'm an EE, I should know this stuff... and I've had access to ESD meters where you can measure the ESD levels and see them reading out at levels well beyond the danger level even when you might think you're "OK".

In any decent tech / EE / PC shop you should get fired on the spot if you're not using full wrist / ankle strap + grounded work mat & floor precautions when doing assembly work.
 

PurdueRy

Lifer
Nov 12, 2004
13,837
4
0
Originally posted by: QuixoticOne
It is an urban legend that you can "feel" static electricity or or feel the spark if there is enough to be dangerous to electronics. You can blow electronics out at ESD levels low enough that you'd never personally feel them.

And grabbing the PC case doesn't help to "discharge" yourself if the PC case isn't grounded directly or indirectly (to a reasonable extent). Many PC cases are mostly plastic anyway, so, again, caution is warranted.

I'm an EE, I should know this stuff... and I've had access to ESD meters where you can measure the ESD levels and see them reading out at levels well beyond the danger level even when you might think you're "OK".

In any decent tech / EE / PC shop you should get fired on the spot if you're not using full wrist / ankle strap + grounded work mat & floor precautions when doing assembly work.

The idea behind touching your case is to bring the potential you have to the same potential of the case. Provided you are at the same potential no spark will occur. There is no need for the case to be grounded for this to be accomplished.
 

Navid

Diamond Member
Jul 26, 2004
5,053
0
0
Originally posted by: PurdueRy
Originally posted by: QuixoticOne
It is an urban legend that you can "feel" static electricity or or feel the spark if there is enough to be dangerous to electronics. You can blow electronics out at ESD levels low enough that you'd never personally feel them.

And grabbing the PC case doesn't help to "discharge" yourself if the PC case isn't grounded directly or indirectly (to a reasonable extent). Many PC cases are mostly plastic anyway, so, again, caution is warranted.

I'm an EE, I should know this stuff... and I've had access to ESD meters where you can measure the ESD levels and see them reading out at levels well beyond the danger level even when you might think you're "OK".

In any decent tech / EE / PC shop you should get fired on the spot if you're not using full wrist / ankle strap + grounded work mat & floor precautions when doing assembly work.

The idea behind touching your case is to bring the potential you have to the same potential of the case. Provided you are at the same potential no spark will occur. There is no need for the case to be grounded for this to be accomplished.

Nicely stated.
:cookie:
 

Roguestar

Diamond Member
Aug 29, 2006
6,045
0
0
Originally posted by: QuixoticOne
In any decent tech / EE / PC shop you should get fired on the spot if you're not using full wrist / ankle strap + grounded work mat & floor precautions when doing assembly work.

Any EE lab and computer lab I've seen in university or business don't bother with the static strap and they seem to get on fine.
 

Navid

Diamond Member
Jul 26, 2004
5,053
0
0
Originally posted by: QuixoticOne

And grabbing the PC case doesn't help to "discharge" yourself if the PC case isn't grounded directly or indirectly (to a reasonable extent).
It brings you to the same potential as the ground plane of the PC.
Many PC cases are mostly plastic anyway, so, again, caution is warranted.
You realize that "PC case" often is referred to what you screw the motherboard to, not the plastic that surrounds it.
When someone says touch the case, they mean touch the metal structure the motherboard and the power supply are attached to using metallic screws.
In any decent tech / EE / PC shop you should get fired on the spot if you're not using full wrist / ankle strap + grounded work mat & floor precautions when doing assembly work.
What is ground on a flying airplane (or the space station)?
Do you think avionics techs working on electronics while the plane is flying have a chain connected to earth to ground them?
 
Jun 8, 2008
58
0
0
Wow, that is a lot of very nice information!

I don't have access to any grounding mats, but I actually found an outlet with a grounding pin in my house, which I'm currently using (via a very large cable extender). I found an old power cable that wasn't in use, took out the power prongs (leaving only the grounding pin), and connected my anti-static wrist strap on the other side in the female grounding slot. Other than that, I have some old anti-static foams that came with my previous motherboard, which should be very useful when needing to place components. Thanks for the very detailed help. :)
 
Jun 8, 2008
58
0
0
Originally posted by: PurdueRy
The idea behind touching your case is to bring the potential you have to the same potential of the case. Provided you are at the same potential no spark will occur. There is no need for the case to be grounded for this to be accomplished.

Isn't this only the case when the component is connect to the case? If you equalize potential electric energy between you and the case, then you may still have potential between you and other components outside of the case that aren't grounded to it.

 

PurdueRy

Lifer
Nov 12, 2004
13,837
4
0
Originally posted by: Unknown Person
Originally posted by: PurdueRy
The idea behind touching your case is to bring the potential you have to the same potential of the case. Provided you are at the same potential no spark will occur. There is no need for the case to be grounded for this to be accomplished.

Isn't this only the case when the component is connect to the case? If you equalize potential electric energy between you and the case, then you may still have potential between you and other components outside of the case that aren't grounded to it.

You will always have that be the case. You cannot guarantee any component outside the case won't have a different potential than you. The best you can do is equalize with the case. Circuit cards aren't exactly great at storing excess charge on their surface. On the other hand, we are quite good at storing some excess charge on our bodies.
 

Navid

Diamond Member
Jul 26, 2004
5,053
0
0
Originally posted by: PurdueRy
Originally posted by: Unknown Person
Originally posted by: PurdueRy
The idea behind touching your case is to bring the potential you have to the same potential of the case. Provided you are at the same potential no spark will occur. There is no need for the case to be grounded for this to be accomplished.

Isn't this only the case when the component is connect to the case? If you equalize potential electric energy between you and the case, then you may still have potential between you and other components outside of the case that aren't grounded to it.

You will always have that be the case. You cannot guarantee any component outside the case won't have a different potential than you. The best you can do is equalize with the case. Circuit cards aren't exactly great at storing excess charge on their surface. On the other hand, we are quite good at storing some excess charge on our bodies.

If I may add 2 comments to this excellent post.

It is a good practice to make the first point of contact with a component to be its ground plane. For example, to pick up a graphics card, pick it up by holding the bracket.
Never make the first point of contact to be a component, like a transistor, on the card.

A component that is disconnected from the PC should ideally be stored in its anti static bag. Just like when you receive a new memory module or motherboard from the distributor. When you first hold the anti static bag, before opening it with the component still in it, you are safely bringing the component to the same potential as your body. It is true that an anti static bag is not a conductor. However, do not think that it is a perfect insulator with a resistance of infinity.
 

QuixoticOne

Golden Member
Nov 4, 2005
1,855
0
0
Exactly, Unknown is correct.

Of course I'm aware that touching object X equalizes the potential of yourself and object X, and that the capacity (as in capacitance) and sometimes the conductance (of parts of) of a big "pc case" is reasonably large and thus the potential of the combination of you + the case after charge transfer will tend to be usefully less than the potential of either alone.

And of course you want the case to have the same potential as you (and your components) when you're sticking parts into said case.

However the benefit of having the case EARTHED instead of floating is that it can then actually dissipate excess charges from you, your work area (if it is conductive like with a conductive mat / table coating), and your environment and unassembled components (assuming conductive straps / coatings / mats / foam are used), et. al.

It wouldn't be unreasonable to think that you + case could be floating at a high static electric potential due to say walking across a carpet and touching the case, and that would still create an ESD problem when a component that had been stored in a distinct enclosure like a box / conductive bag is touched by either you or the case when you/case is floating. More things can be assumed to have leaked to "near earth" potential than to be floating at random high potentials, thus the benefit of having the work area earthed rather than floating at some partly consistent but possibly high potential.

As I said before, nothing is perfect unless you use conductive work areas, straps, earthing, and an ion blower to neutralize any locally accumulated charges on insulating surfaces. Just doing some of the above leaves risks of one kind or another.



Originally posted by: Unknown Person
Originally posted by: PurdueRy
The idea behind touching your case is to bring the potential you have to the same potential of the case. Provided you are at the same potential no spark will occur. There is no need for the case to be grounded for this to be accomplished.

Isn't this only the case when the component is connect to the case? If you equalize potential electric energy between you and the case, then you may still have potential between you and other components outside of the case that aren't grounded to it.