Grounding ESD band - Page 1
Forum section: electronics / beginners

author: bootloader9800
author_rank: Contributor
timestamp: March 15, 2021, 01:34:05 pm
content: Hi Folks!I just bought this ESD wristband. The instructions tell me to attach it to some sort of ground box. I dont have a ground box.1) Could I safely attach the other end of the ESD strap to the negative terminal of my power supply? Will that be safe and ground me?OR2) Could I just attach the other end of the ESD to a small piece of metal, like an empty soda can, large metal bolt or a hunk of metal? ( Very hard to find a bare piece of metal. Everything seems to be painted.)Both pics are below.Ty for your replies!

author: CaptDon
author_rank: Super Contributor
timestamp: March 15, 2021, 02:35:24 pm
content: I assume your power supply has a 3 pin grounding plug?Ground your strap at the receptacle??

author: wraper
author_rank: Unknown
timestamp: March 15, 2021, 03:02:42 pm
content: PSU output usually is floating, not suitable for grounding.QuoteSome piece of metal is just a floating piece of metal, nothing to do with grounding. For grounding you need mains ground/earth. It's often connected to metal enclosure of electric equipment.

author: Ian.M
author_rank: Super Contributor
timestamp: March 15, 2021, 03:19:15 pm
content: First, check the resistance of the lead from the snap-stud on the wrist band to the croc clip. If its under 500K its *NOT* safe to use. The resistance *SHOULD* be approximately one megaohm.To be effective for ESD control, the wrist strap needs to be connected to the same ground as the ESD mat you *should* be working on. A lesser degree of protection can be achieved by clipping it to the grounded chassis of whatever piece of equipment you are working on, but even with the wrist strap, there is a significant risk of ESD damage to loose sensitive parts while handling them out of their ESD dissipative packaging if you put them down anywhere other than their final location, or pick them from their packaging without holding it in your other hand.

author: bootloader9800
author_rank: Contributor
timestamp: March 15, 2021, 04:41:00 pm
content: Quote from: CaptDon on March 15, 2021, 02:35:24 pmYes. The power supply has a 3 prong. Can I attach the strap to the front of the power supply where it says " - " ( minus )?

author: bootloader9800
author_rank: Contributor
timestamp: March 15, 2021, 04:42:55 pm
content: Quote from: Ian.M on March 15, 2021, 03:19:15 pmTy.Hmm....I have a new question....Does handling these ESD sensitive components with wooden chopsticks solve the problem?

author: TimNJ
author_rank: Super Contributor
timestamp: March 15, 2021, 04:57:03 pm
content: Quote from: bootloader9800 on March 15, 2021, 04:41:00 pmOnly if (-) is connected through to earth. For most bench power supplies it is not.

author: fordem
author_rank: Regular Contributor
timestamp: March 15, 2021, 06:43:24 pm
content: Quote from: bootloader9800 on March 15, 2021, 04:42:55 pmNo - it introduces the potential for more problems.The idea of the ESD band is to discharge any potential static charge in a controlled fashion via the 1 Megohm resistor. The potential static charge may be on you, on the device, on the chopsticks, on your work surface, etc.If the band is going to be used in a fixed location then it would be best to install a suitable ground system, if it's for use in different locations, then it needs to be used with a portable ESD kit that will allow charge to be equalized between you and the device you're working on.

author: CaptDon
author_rank: Super Contributor
timestamp: March 16, 2021, 01:47:14 pm
content: The plus and minus outputs of your supply are not necessarily referenced to the grounded chassis of the supply. Connecting to minus may actually be a bad thing!!

author: Terry Bites
author_rank: Super Contributor
timestamp: March 16, 2021, 02:02:56 pm
content: Get yourself some of these

author: ricard2k
author_rank: Unknown
timestamp: March 17, 2021, 08:20:38 am
content: A simple line socket wiring only ground to a 10Mohm resistor is what you need. If you want a better isolation use 10x1Mohm resistors in series to avoid a short in them.

author: wraper
author_rank: Unknown
timestamp: March 17, 2021, 12:05:09 pm
content: Quote from: ricard2k on March 17, 2021, 08:20:38 amThat band should have built-in resistor already.