Using anti-static wrist strap to ground against laptop

You do not want to ground yourself to the laptop. You want to be grounded to earth.

The anti-static wrist strap should have come with an attached wire. The other end of that wire should be connected to an electrical ground. The center screw of the AC wall outlet holding the cover plate is a suitable connection point that is tied to your dwelling's ground (assuming you have 3-prong outlets and the outlet is properly wired and up to code). Make sure you attach to bare metal and not the paint on the screw.

Once you are grounded, you do not want to touch any live circuit. So the equipment should be turned off and unplugged. Ideally, especially with high voltage devices, you should use the hand that has the strap to poke around and the other hand behind your back or in your pocket. The idea is that if you do get shocked, the electrical current only has a path from your hand to the strap, and not across your chest and heart.

sawdust

Posted 2011-08-11T09:52:22.433

Reputation: 14 697

1@sawdust: "Once you are grounded, you do not want to touch any live circuit." Assuming you're using a proper grounding wrist strap + cable, this is not an issue. All such setups have a 1 Mohm resistor in series. Even 500 V can only push half a milliamp through that. This does NOT mean that it is safe to work on powered equipment (there might be some other much lower-impedance path through you to supply ground); it does mean that the ground strap in no way increases the risk of dangerous electric shock. – Jamie Hanrahan – 2014-10-08T06:23:27.703

sawdust and mike-insch tell you explicitly to not connect to the laptop, but connect to Earth itself. As @Daniel-Andersson points out their answer is downright wrong. The laptop itself may have an whole different potential than the Earth, causing the potential form the laptop to flow away though you when you handle it. That was exactly waht you wanted to avoid, as it might damage the components of the laptop. Please also have a look at https://superuser.com/questions/975427/how-to-properly-use-an-antistatic-wrist-strap-when-working-on-a-desktop-pc/1055702#1055702 for a more detailed answer.

– Static Storm – 2018-09-09T16:56:07.767

1But i heard i can ground to laptop which is plugged in AC outlet while shut down. This is not true? – Boris_yo – 2011-08-11T10:56:13.620

2No, you cannot ground to a laptop connected to an AC outlet - the laptop's power-supply is where the connection to the electrical earth stops, there is no electrical earth within the laptop chassis. You should always connect your wrist strap directly to an electrical earth and never to the equipment you are working on, regardless of whether it's a laptop, desktop etc. – Mike Insch – 2011-08-11T11:23:26.737

@MikeInsch Thanks Mike. Just to make sure, in case I work with desktop computer, I ground to computer's chassis or power supply? I often have heard about former by the way. – Boris_yo – 2012-08-29T14:36:01.873

1@Boris_yo While you can leave the AC cord connected to the power supply and then ground off to the PSU or Chassis, I personally wouldn't recommend doing so - a faulty RCD / RCBO on the supply circuit and / or a faulty Power Supply could cause current to conduct to earth via you, and while unlikely it's not worth the risk. If you must ground yourself to the equipment, you can ground to the Chassis only if the PSU is still properly mounted and electrically and mechanically connected to the Chassis, otherwise you must ground to the PSU itself. – Mike Insch – 2012-08-29T14:55:36.570

@MikeInsch So you don't recommend grounding to chassis, PSU or any equipment at all that has faulty supply unit while AC power is connected from mains? Or you generally don't recommend connecting to anything but only from wall socket's ground? – Boris_yo – 2012-09-01T11:19:20.457

2The bit about high-voltage devices really doesn't belong here. We're talking about working on a laptop, using a strap to avoid damaging it with static electricity. The kind of device where high-voltage might be present (such as a PSU) is not something the amateur should open up anyway; safety considerations aside, it's too easy to destroy the system if you don't know what you're doing. – Isaac Rabinovitch – 2012-11-22T18:17:36.193

1As the above poster says: this is not about HV. The goal is to avoid static discharge (ESD) from potentially (ha!) ruining sensitive electrical components. The only thing of concern is for your body to have the same potential as the laptop—nothing else. It is not helpful to ground oneself to earth ground if the laptop itself is not plugged in to an earthed wall socket. So this answer as it stands is wrong for the application in question: you do want to ground yourself to the laptop, to avoid ESD (for HV applications, an ESD wrist strap won't be able to handle the load anyway). – Daniel Andersson – 2012-11-23T07:01:01.050

An anti-static mat might help. You may place the motherboard on the anti-static mat, and connect your wristband to the mat. The mat should have such a low resistance by design, that it will accomplish the same as attaching to the motherboard directly. Of course you would first have to remove the board from the chassis before placing it on the mat. while doing that, you have to be connected to the board itself. But at least after placing it on the mat, you have more freedom to handle the board using a mat. – Static Storm – 2018-09-09T16:59:08.813

1Sometimes one can access fastener screws for e.g. VGA connectors. That might work as chassi ground. – Daniel Andersson – 2012-11-22T18:14:23.793

Using anti-static wrist strap to ground against laptop

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