Question About Anti-Static Wristband and Grounding

[888888]

Now that the time has come to once again build a new computer, I have decided to do something smart and purchase a Belkin anti-static grounding wristband. However, I am quite confused on how to use it.

I have found so much conflicting information on the net about how to ground myself with it that it's made my head spin. So I came here looking for a final, definitive anser.

I have an ATX mid tower case. I know I am supposed to clip it on an unpainted part of the inside of the case. However, do I keep the power cable plugged into the power supply in the case? I have read so many sites that have said NEVER to work on a plugged in computer. I have also read many sites that have insisted that an anti-static wristband won't work unless the computer is plugged in.

I will be working on a wooden table with one leg on the wooden floor and the other legs on the carpet.

Please help!

[bazooka]

You can do either or.

I personally do not plug it it until it is completed.

Through the seven systems that I have built so far, I have yet to go wrong.

[888888]

You can do either or.

I personally do not plug it it until it is completed.

Through the seven systems that I have built so far, I have yet to go wrong.

I knew I could count on you for an answer Bazooka.

However, my question then is how is a computer grounded if it is not plugged in? What if a computer is suspended in the air by wool strings, can you still ground yourself with it?

If not, is it because the case is sitting on the floor? What about the carpet?

Thanks.

[bazooka]

As long as you are not on carpet, and you have touched the metal part of the case, you have discharged whatever static electricity you had.

The guys on techtv do not even use a grounding strap.

[rallynavvie]

I've built two pretty expensive SMP systems in my own house with no anti-static gear and have bumped stuff around in a case while the computer was still on and never had problems. I think you really need to wind up some good static in order to really hurt a component. As long as you touch a steel part on the chassis after dragging your feet across the carpet in leather-soled shoes I think you'll be OK.

[Bandarlog]

Finally a topic I can GIVE advice on (teach HS physics).

You really don't care if you and the computer are "grounded". All you care is that you and the computer are at the same "charge". When static electricity leaves your body with a jolt, electrons are moving either from or to your body to equalize the charge. If you and the machine have equal amounts of charge there's no place for the electrons to go. It is the moving of these electrons, the amount (current), and the force (voltage due to amount of charge difference) that cause problems with computer components.

I don't use a strap, but touch the box to release build up of charge any time I walk somewhere and come back. When working on the box, I lay my arms on the case, thus allowing the charge to equalize by itself before my hands touch the components.

[holistic]

.....blah ...
I don't use a strap, but touch the box to release build up of charge any time I walk somewhere and come back. .......blah ...

Agreed . Have built many a computer without a ground strap and had no issues yet .... touch metal PD - potential difference

[Dr. DOS]

My wrist band comes with a banana plug adapter that plugs into a ground part of a 3 prong recepticle. That is by far the best possible ground. If I'm down in my basement working on a machine I ground to a water pipe above my head. 2nd best ground location. Both provide very good shock grounding ...

[Jayhawk]

When I slide across my carpet and touch my cat, there's a spark. SHould I plug my cat in?.

[bazooka]

When I slide across my carpet and touch my cat, there's a spark. SHould I plug my cat in?.

Yeah, what the heck.

Be prepared for a pissed off cat though.

[Jayhawk]

I lay my arms on the case, thus allowing the charge to equalize by itself before my hands touch the components.

I have not done that exactly but I have laid my hands on a bad hard drive in an attempt to heal it. Didn't work.

By the way Bandarlog, an excellent (and accurate) comment.

[888888]

Finally a topic I can GIVE advice on (teach HS physics).

You really don't care if you and the computer are "grounded". All you care is that you and the computer are at the same "charge". When static electricity leaves your body with a jolt, electrons are moving either from or to your body to equalize the charge. If you and the machine have equal amounts of charge there's no place for the electrons to go. It is the moving of these electrons, the amount (current), and the force (voltage due to amount of charge difference) that cause problems with computer components.

I don't use a strap, but touch the box to release build up of charge any time I walk somewhere and come back. When working on the box, I lay my arms on the case, thus allowing the charge to equalize by itself before my hands touch the components.

Lets' say I am taking a new motherboard out of the bag it came in. Is it sufficient for me to be hooked up to the chassis of an unplugged computer when touching the motherboard? What does it matter if me and the case are of the same charge when the motherboard isn't? I will mostly be installing new parts into the case, not move around ones already in there.

Thanks.

[rallynavvie]

Most important thing with the board is not to touch components to leave oils on them at all. In keeping with that you shouldn't need to worry about static discharge as you're holding inert portions of the PCB.

[888888]

Ok. Well thanks for all the replies. I am building my system tomorrow and have made my decision as to how I will use the anti-static wristband. I will attach the alligator clip from the wristband on to a metal part in the radiator which has water pipes inside. I believe this has proper grounding. I will keep my system unplugged until it is completely done. It is written on my ASRock motherboard to always unplug the system before putting in add-in cards and the like. I think I will follow their advice. If I ever do need to install a PCI card or more memory, I will attach the wristband to the case chassis, then unplug the system. I believe that in an upgrade scenario, such static protection would be sufficient. I would not able to use the radiator during an upgrade because it is to far away from where I will put the system.

I will leave you with a quote from the most informative site I have found on th net dealing with grouding oneself during computer construction. It is from pccomputernotes.com.

At the very least, you should use an anti-static wrist strap
connected to the bare, unpainted metal of your case’s frame. There are two schools of thought on this subject:
One is to leave your computer plugged in. Any static buildup is discharged along your wrist strap to the computer's case, then through the power cord into the ground receptacle of your electrical outlet.
The second is to unplug your computer. With the wrist strap attached, this should put you and your computer at the same potential charge and no transfer of electrons should take place.
This becomes a decision you have to make for yourself. A lot of books will suggest that the computer remain plugged in, and in fact, the A+ Certification exam considers this the correct choice at this time (which is probably why these books suggest it). However, when you leave the computer plugged in, it’s a little too easy to turn it on when you’re working inside; or forget it’s on and plug in an expansion card or drop a screw onto the motherboard. Also, you have full AC power going to the remote power switch on the front of your computer. If there is a bared wire, or open contacts on the back of the switch, you could get quite a shock. Remember too, that today’s ATX motherboards have power to them even when the switch is off.

Man, you can't get a straight and precise answer out of anybody on this subject. Oh well.

[bazooka]

I gave you a straight answer.

You do not need to have it plugged in.

You can put the alligator clip inside the case attached to metal.

Touch the case and you are ok.

You do not need to attach to a water pipe or anything like that.

That is about as straight as you can get.

There is no set way to do things.

That is why you get different answers.

[888888]

I gave you a straight answer.

You do not need to have it plugged in.

You can put the alligator clip inside the case attached to metal.

Touch the case and you are ok.

You do not need to attach to a water pipe or anything like that.

That is about as straight as you can get.

There is no set way to do things.

That is why you get different answers.

Sorry Bazooka, I did not mean I can't get a straight answer out of you guys on the forum but rather the various PC building websites online. Looking back, my comment does seem rather *******-ish, but it was late and I was tired.

Anyway, thanks for the clarification. I think I will still attach it to the water pipe cause I am already used to that, but in the future, I will use the non-plugged in method with clip on chassis for upgrades. Thanks.

[stiltman]

When I taught A+, I made sure students used grounding straps. However, personally, I never use them at home and have never had a problem.

[dxj40c]

Banderlog is correct. You don't have to be 'grounded' just 'bonded' (having the same charge as the computer). If you want to be bonded and grounded, just clip a wire from the case to a 'ground' (water pipe, the little screw that holds the wall socket plug-plate on, or the chassis of something that is pluged into a grounded circuit).

As long as you touch an unpainted part of your computer chassis before you start joining things and don't go anywhere else, you will be ok. You can build up a lot of static electricity by walking across carpet. That little pop you get when you grab a door knob is about 10,000 volts (with no amps). It's the amps that will fry you.

[Capmaster]

When I slide across my carpet and touch my cat, there's a spark. SHould I plug my cat in?.

Yeah, what the heck.

Be prepared for a pissed off cat though.

Funny you should mention pissed-off cats Like water, cats don't care for electricity much. One winter before I had hooked up the humidifier I walked across the room (carpeted) and pet our cat KC. It drew an inch-long arc off her nose, she shot up, dashed out of the room, and we didn't see her the rest of the day

Wrist straps are always the better way to go, but vendors realize people are probably not going to dash off to buy one before assembling, so they offer the alternative of touching the PS case while the unit is plugged in, but off. Touching the case while it's unplugged would be pointless. This method is barely adequate, and relies on the case to have good conduction to the ground. In this day of mass-produced units and self-tapping screws threaded into non-ideal materials, with cheap plating, it isn't always a sure thing. One loose screw could isolate that cover from ground, and ZAP!

Most modern CMOS ICs have some sort of zener overvoltage and polarity protection built-in. Zener diodes shunt any voltage above the device's design to ground. Usually 6 to 20 volts depending on the circuit they're used in. They also serve to act as a regular diode when a reverse polarity is applied, protecting from a negative-going static spike too. But they're not rated for any sort of appreciable power ...just enough to catch static charges ...lots of voltage, almost no current.

Some are good for one zap before they blow, and others are robust enough for repeated zaps provided the current isn't too high. Current causes heat and heat kills semiconductors. Lose that protection and the next time you touch your motherboard might be the last.

Use a wrist strap and clip it to either the ground pin in the outlet, or to a water pipe. Then you don't have to worry if you have already blown out your one-time CMOS protection. You can get the straps for a couple bucks at Radio Shack

[888888]

Currently typing from my brand new system. Assembled everything with the wristband attached to the radiator. Hopefully I didn't zap anything even a little bit.