Introduction: Grounding an ESD Mat and Wrist Band at Home.
Electrostatic discharge is no laughing matter. The discharge voltage can reach tens of thoushands of volts, although it is low amperage. It usually takes several thoushand volts before humans can feel the discharge, such as walking across carpet with socks and touching a metallic surface. As little as 3 volts can damage components such as microprocessors. I will show you how to ground yourself and work surface at home. I was able to achieve this for under $5 as I used items that I already had. You can buy a kit that has everything you need but you will still need to follow the instructions for hooking up to ground. Let's get started.
You should make sure that your home has proper grounding before attempting this instructable.
Esd mat- we used to buy this by the roll at a previous employer so I had a small piece
Wrist Strap and cord- again already had this from a previous employer
Female banana plug
Ring terminals (qty 2)
Grounding household plug
Machine screw w/NUT- I used 1/4"x20x1"
Washers (qty 3)
Heatshrink -this is optional I just think that heastshrink makes things look a little nicer.
Wire -I used 16ga
The images are in order by step.
Make the wrist strap adapter.
If you buy a kit it will come with a hub that attaches to the mat via a snap, when the mat is on a roll it will not have this snap, so I just used items that I already have. Strip the wire and crimp a ring connector to one end , strip the other end and solder it to you banana plug. I used heatshrink over the post of the banan plug and the ring terminal.
Make the ground interface.
Remove the AC blades from the plug so no one gets shocked. Cut the wire to length ,strip both ends. Attach one end to the ground post terminal on your plug. Crimp a ring terminal to the other end again use heatshrink if you would like.
Grounding the mat and wrist strap
You can decide where to insert the bolt depending on your space. I chose the upper right corner as I am right handed. Used an Xacto knife and cut a slit vertical and the another horizontal making a cross , yes you can use other means but this is what I did. Place a washer on the bolt then insert the bolt through the mat from the bottom side up. Place another washer on the bolt. Now take the grounding plug and your wrist strap adapter and slide the ring terminal ends on the bolt. Place another washer on the bolt and use the nut and hand tighten.
Making the connection
Now plug the grounding plug into the ground on your receptacle, no risk of shock as there is no AC. Plug your wrist strap up and your are nowgrounded as log as you are strapped in.
Take a multimeter and test your wrist strap, you should have somewhere around 1M ohm resistance. Now, test from your wrist strap to the plug and ensure you don ot have a dead short. Now check from the grounding point on the mat to your earth ground you should have less than 1 OHM resistance according to the ESD Association.
Remember to never work on anything live even low voltage , I know this is one of the first things you learn but we are all guilty of it at some point
I hope this writeup comes in handy and saves some components from ESD. Thanks goes to Mik for his comment which made me realize a few things need to be added.