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| Thread ID: 21799 | 2002-07-04 05:45:00 | Antistatic Procedures | prism (840) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 59811 | 2002-07-06 08:43:00 | That sounds like sime very good advice Billy. But I'd just like to add in that if your hands are that sweaty. You should leave it a while before you power your PC up again -->> liquid and electricity don't go together well. ;) |
-=JM=- (16) | ||
| 59812 | 2002-07-06 10:12:00 | perfectly put billy. that needs to be in FAQ's. :) | tweak'e (174) | ||
| 59813 | 2002-07-06 10:22:00 | Well said Billy, you brought it all back on track. I know the law is the law and all that, but when I came to NZ from the UK some 25 years ago, it was immediately obvious that tradesmen protectionism was primarily behind the regulations governing plumbing, drainage and electrical work. Do it yourself was a joke here compared to UK. Remember Alan Martin campaigning to have the law relaxed? I would even go as far to say that there has been a deliberate lack of education in matters electrical in order to keep the population in fear and dread of the electron. I even heard a local electrical shop owner tell a customer he was not allowed to replace his jug element, and the poor sucker believed it! In contrast to NZ, back in the UK DIY plumbing and electrical work was common place as witness reading any UK DIY magazine/book, and people were not dropping dead through it. Wiring standards were also higher there, at least in newer houses, with ring-main wiring and earth current trips, some 40 years ago. I was horrified when I first opened my power board in the house we bought here, and all this wiring sprung out at me. Talk about a rats nest. Anyway, be that as it may, thank god this is not Queensland. The rules there......... The reason a high resistance is connected in series with anti-static devices is to limit current flow to a safe level in the event of a device becoming 'live'. There is one built into every wrist strap. It's not so important with an anti-static mat as the conductivity is low any way, probably of the order of 1 megohm per square, though I havent measured it. |
Terry Porritt (14) | ||
| 59814 | 2002-07-06 21:16:00 | May seem a silly question Terry but how could a device become "live" when it is disconnected from the power source? Surely we're not servicing a monitor with one hand whilst replacing a CPU with the other? Cheers Bob |
B.M. (505) | ||
| 59815 | 2002-07-06 23:03:00 | I was just thinking generally of an electronics workbench that has an anti-static mat, and could have all manner of equipment on it being worked on from time to time. The principle is you dont want a direct low resistance path to earth, that can be fatal. The one hand in the pocket business may be ok for some, but I could never work one-handed :) I'm surprised the sparkies havent yet risen to the bait, I was expecting a bit of a ding-dong, I'll keep my powder dry for the time being :D |
Terry Porritt (14) | ||
| 59816 | 2002-07-06 23:46:00 | Well B.M. , Terry seems to have answered your question re the resistance okay. The high resistance is too prevent electric shock from live equipment while safely diffusing the high static voltages. As billy said, we went a bit off track, but if you want some good info on the e.s.d. topic, here's an interesting link: www.static-sol.com B.T.W Terry, I lived in the UK for some years and saw some pretty shoddy electrical installations there, just as I have seen many here. While I agree that a lot of the legislation here might (seem to) be trade-protectionism, the prime motive has always been safety. The most inane ruling though was that which legally prevented (still prevents? - I'm not sure) instruction of non-trade persons in any of the aspects of electrical work. I believe that the Electricity Act is currently under review and that most of the safety aspects will become the resposibility of OSH, under the Health and Safety in Empoyment Act. Maybe then, we will be allowed to instruct the home handyman to safely carry out electrical work. Also, up until 1993, the shop owner was correct. All the home owner was legally allowed to do up till then was rewire a fuse or refit a plug. Fitting a new element to a jug was illegal! Crazy eh! Regards, Andy |
andy (473) | ||
| 59817 | 2002-07-06 23:54:00 | > I'm surprised the sparkies havent yet risen to the > bait, I was expecting a bit of a ding-dong, I'll keep > my powder dry for the time being :D Not sure what bait you are referring to, but I'm betting that they aren't game enough to take on our Billy. :D Billy, well done! It shouldn't take five minutes to copy and paste that into your very own "FAQ #47 What antistatic procedures should I take?". ;-) Actually the FAQ number should be somewhat lower but 47 will have to do for now. |
Susan B (19) | ||
| 59818 | 2002-07-07 00:29:00 | Well Susan, over the years in Oz there has been great debate between electronic techs/engineers and registered electricians over who can do what . It is ongoing as readers of Silicon Chip and the defunct EA mags will well know . I thought maybe it would start up in this posting too . I agree with Andy, house wiring in the UK before about 1960' ish could be quite dreadful with 2 pin sockets, no earth wiring . The first house we bought, the owner proudly told us it had been rewired by the local electricity board . Well some 3 pin sockets had been fitted but it was too big a job for them to get the floor boards up (upstairs) to run earth wiring around! On the other hand in the UK, there has always been extensive education of the public in matters electrical via schools, magazines, night school, etc . In this country as Andy says there has been active suppression of electrical knowledge for the masses, generating the 'fear and dread' of the subject . I maybe didnt make it quite plain that it is your body that should not be connected to a low resistance earth . |
Terry Porritt (14) | ||
| 59819 | 2002-07-07 01:10:00 | Ahhhhhh I see. Now someone has livened my mat up with a third party device and because there is 10meg between the mat and earth I'm going to supply the route of least resistance when I pick up my kettle that is bubbleing beside me. That's not very nice is it. I think I'm being had on again? teeeheee! |
B.M. (505) | ||
| 59820 | 2002-07-07 02:46:00 | No No B.M. - as you are connected to the mat also by a resistive bonding strap, you are at the same potential as the mat, so won't get zapped (well, that's the theory). Unless of course, you are earthed through some other means, which defeats the purpose of the static-safe workstation anyway. Lets just go with Billy's procedure. Its certainly concise and unconfusing. I'd have to admit that this is what I generally do anyway. I only drag out the mat and leads for a full system rebuild. Cheers, andy |
andy (473) | ||
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