Where to plug earth?! - Page 1
Forum section: electronics / beginners

author: sean87
author_rank: Regular Contributor
timestamp: December 28, 2012, 06:55:37 pm
content: Hi all,So I bought a ESD protective pad for my workbench. It comes with some sort of aligator clicp that should be connected to earth ground I beleive. Can I just plug it to a earth terminal of a wall socket?

author: amateur_25
author_rank: Regular Contributor
timestamp: December 28, 2012, 07:27:09 pm
content: If you have anything that has a metal casing on it i.e. pc chassis that should be connected to the earth ghround usually via an IEC connector at the back.So just clip onto the case. People who repair pc's do the same when they're handling the sensitive components such as the cpu. You could use one of thesebut they take a press stud fitting. shouldn't be too hard to find a cable for it I would think.http://compare.ebay.co.uk/like/350514169416?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar&cbt=y

author: PA0PBZ
author_rank: Super Contributor
timestamp: December 28, 2012, 08:12:34 pm
content: Quote from: sean87 on December 28, 2012, 06:55:37 pmYes.

author: vk6zgo
author_rank: Super Contributor
timestamp: December 29, 2012, 02:33:42 am
content: Quote from: PA0PBZ on December 28, 2012, 08:12:34 pmBUT be very careful that itisthe earth terminal.Also,if you use a mains plug with the wire connected to the earth terminal inside,make sure that the ESD earth wire cannot contact either of the other two terminals.I've seen these earth wires just roughly wired into a normal OZ type power plug with no strain relief so the wire can just flop around inside the plug---AAAARRRRGGGGHHHH!

author: Neilm
author_rank: Super Contributor
timestamp: December 29, 2012, 09:58:13 am
content: Quote from: vk6zgo on December 29, 2012, 02:33:42 amSeconded - I was working on a project at work (here in the UK) that was designed to run from an inverter. I was doing some testing and plugged it into the mains. No problem, until I realised that I hadn't connected the earth. I quickly rectified this, plugged it in, touched the metal case and OUCH it hurt.Turned out that the building had been mis-wired, the earth lead was connected to the live phase rather than the neutral.Neil

author: Psi
author_rank: Super Contributor
timestamp: December 29, 2012, 10:12:05 am
content: Quote from: Neilm on December 29, 2012, 09:58:13 amWas the busbar earth-neutral link between earth and phase ?"mis-wired" is such an understatement.That building would have been a death trap

author: Neilm
author_rank: Super Contributor
timestamp: December 29, 2012, 10:18:03 am
content: Quote from: Psi on December 29, 2012, 10:12:05 amI have no idea - once I realised that I was getting shocks due to the earth not being earth, I stopped work and told my boss. The building had been vandalised and set on fire a few months before, so I guess that the fault had been introduced in the repair. I do know that it affected every socket in the unit so it wasn't a case that the ring main had been swapped over as there were several different ones for parts of the unit.Neil

author: ftransform
author_rank: Frequent Contributor
timestamp: December 29, 2012, 02:41:18 pm
content: Quote from: Neilm on December 29, 2012, 10:18:03 amSounds like people love your workplaceConsider wearing a bullet proof vest there.

author: quarks
author_rank: Frequent Contributor
timestamp: December 29, 2012, 02:59:48 pm
content: In my opinion, you should spend the money for one of these special connectors. They are not expensive and ensure that you cannot accidentally kill yourself while hooking up and have at least 1MOhm resistance between you and ground.

author: free_electron
author_rank: Super Contributor
timestamp: December 29, 2012, 03:43:39 pm
content: dig a little hole in the backyard. insert a freshly cut and stripped piece of copper. plant in direct sunlight , water weekly... after a few months this copper wire will sprout new copper wires. these are now organically grown earth leads...

author: ftransform
author_rank: Frequent Contributor
timestamp: December 29, 2012, 03:45:27 pm
content: I wired mine esd mat to the center screw on the outlet. I don't know if euro outlets have one though.Much better then a plug because you need a screw driver to change it, so its unlikely to get messed with.You can always use a voltstick if you are paranoid.And I wire my wrist strap to the GND banana jack on the power supply.

author: cybergibbons
author_rank: Frequent Contributor
timestamp: December 29, 2012, 04:32:09 pm
content: Quote from: Neilm on December 29, 2012, 10:18:03 amCould it have not just been a lifted earth? These are fairly common and don't notice, but phase to earth is rare, and would have required nothing else to use earth, or someone else would have got a belt.

author: nanofrog
author_rank: Super Contributor
timestamp: December 29, 2012, 08:40:55 pm
content: I made an adapter that ties an additional wire into the ground pin, and plug it in a GFCI (nothing to mess with in the outlet itself to access safety earth). Essentially this (http://www.idealindustries.com/prodDetail.do?prodId=61-176). The ground wire out of the adapter then connects to a grounding block. Rather easy and inexpensive to make.