How should you ground yourself?

[KILLCIDE]

I got pretty sick of always having to ask my friends for tools whenever I have to do something to my computer, so I took it upon myself to buy a toolkit. The toolkit I got came with an anti-static wrist wrap, but I have no idea how to use it. I've looked online and saw extremely mixed reviews of how to ground yourself with it.

Let's say I start building a computer, how should I properly ground myself to prevent the damaging of components? I know that you have to be pretty careless to do it, but since my toolkit came with an anti-static wrist wrap, I figured I should put it to use.

 

[Flux]

Ah yes, I remember using those "anti-static wrist wrap" you speak of when working with micro-controllers. What we do is connect the "wrist wrap" to a grounded metal to avoid ESD on the micro-controllers.

 

[KILLCIDE]

What we do is connect the "wrist wrap" to a grounded metal to avoid ESD on the micro-controllers.

I've read this also, but many said that it had to be bare metal and not painted?

 

[Dr Super Good]

You need to connect it to the ground of what ever you are working with.

I would imagine that when a computer is powered down and disconnected, simply holding the case is enough since the ground will probably float to the same potential as the case and you will want to raise the components to the case potential anyway.

When it is powered up the case should be at ground potential for safety reasons, which may be very different from neutral. Further more the internal potential is based on the DC produced from the PSU, which may or may not reflect neutral potential from the mains. This is where damage is most likely to be caused from static as a component sitting on isolation material is probably at a different potential level. I would not recommend messing around with components while the PSU is connected to the mains.

Static will only cause damage if it hits the sensitive components which have small connection circuits. If it were to hit massive connection circuits like the ground or power then it is unlikely any damage will be occurred due to the capacitance and inductance present.

I think air moisture plays some role in the static risk level for components. Dry air and skin is generally more prone to building up large potential differences due to the isolating properties,. Moist air and skin generally is less prone as charge gets distributed more easily.

Avoid static prone clothing. The classroom static experiment example of a wool jumper or rubbing plastic shoes on laminate floors is probably not the sort of clothing you want to wear while working on a computer. A cotton T-shirt and barefoot on the other hand will probably not be a problem.

I have worked on many computers and manipulated many micro controller circuits without any wrist strap and none have been damaged due to ESD. The components are more tough than you would think and are designed to cope with ESD to some extent (otherwise they would break no matter what you did). ESD is only a problem if large potential differences are involved. For example if you charge yourself up with a Vandagraph generator then there is a fairly good chance ESD will break something.

 

[KILLCIDE]

I would imagine that when a computer is powered down and disconnected, simply holding the case is enough since the ground will probably float to the same potential as the case and you will want to raise the components to the case potential anyway.

This is how I've always done it. I've also made sure to not work on carpet. However, since my kit came with this wrist wrap, I figured I'd use it xD I just want to know how to use it properly. Should I install the PSU first into the case, and then plug the PSU into a wall socket while having the switch off and then attaching the alligator clip to the metal bracket?

 

[Dr Super Good]

Should I install the PSU first into the case, and then plug the PSU into a wall socket while having the switch off and then attaching the alligator clip to the metal bracket?

As I already said, mains ground and neutral may not be the same potential. For safety reasons the case is connected to ground. Ground may not be the same potential you are at, to the point you could get shocks from devices. Due to the nature of ground these shocks are usually trivial to humans (they might not be if ground connection is bad so it can float to mains voltages) however it could be enough to damage components. It all really comes down to your power quality in the area you are working.

As such it will generally be safer if you put the PSU in but do not plug it into the mains (this applies to practically every device you are fixing). Hold the case while working or attach the wrist strap to the case. Avoid touching the components or connections on any circuit boards and instead touch the edges or heat sinks of circuit boards.

 

[KILLCIDE]

As such it will generally be safer if you put the PSU in but do not plug it into the mains (this applies to practically every device you are fixing). Hold the case while working or attach the wrist strap to the case. Avoid touching the components or connections on any circuit boards and instead touch the edges or heat sinks of circuit boards.

Ahh so as long the PSU is not connected to the actual mobo or any component in the case, but is still plugged into the wall, it is okay to work on?

 

[Dr Super Good]

Ahh so as long the PSU is not connected to the actual mobo or any component in the case, but is still plugged into the wall, it is okay to work on?

No it should not be connected "into the wall". This is a general safety tip, you should never work on anything that is currently plugged into the mains (unless you really know what you are doing).

Although usually safe, if your area or home were to suddenly suffer a catastrophic dip in power quality while you are working on the computer when it is plugged in it could electrocute you. For example if ground were to suddenly float due to a defective appliance (can happen if ground wire is poorly installed or very old so bad connection into the ground) then the casing of your computer could become connected to the live wire. If you are inside it, trying to work on it on a moist concrete floor you might find yourself being electrocuted. Generally this will not happen if you touch an assembled computer due to a combination of paint on the outside and that you will be more likely to break away from it if it does happen.

In theory switching the isolation switch off on the back of the PSU should be enough. However if it is enough depends on PSU design so personally I think it is better to leave it unplugged when doing heavy modifications on a computer system. Additionally if your area has pretty good power quality (reliable, not in a thunder storm etc) then you can probably do it when plugged in as the risk is minimal.

 

[KILLCIDE]

No it should not be connected "into the wall". This is a general safety tip, you should never work on anything that is currently plugged into the mains (unless you really know what you are doing).

Ahh sorry, I thought you were referring to the ATX connectors on the motherboard as a "main". Thank you for the detailed explanations!