I looked at the service entrance of my house and I saw what I feared: - alu wire bolted down with an allen-wrench type bolt into the lug attached to the bus bar running along the breakers - discoloration on the insulation nearest the clamp, indicating that the connection has already overheated in the past. So, I will make sure to re-do this connection before I need to draw significant current and cause the wire to burn out of that lug, I have seen the results of that mess before (meeting room at a retreat in the woods, the perfect combination of intermittent use and a moist outdoor environment enhancing the corrosion of the contacts - luckily they had a genset and a change-over switch since the power to that center went out regularly anyway)
Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: [email protected] Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Michael Ross Sent: Tuesday, January 14, 2014 9:41 AM To: Electric Vehicle Discussion List Subject: Re: [EVDL] Dissimilar Metal Contact on LiFePO4 Battery Posts No, I'm not surprised and the leaching and tracking it around won't do much either. I have been sloppy saying grease and paste. A silver paste will do more. Not a grease at all. But really clamping force is the hot tip. So NoAlOx doesn't do much to improve conductivity. Or is that a misinterpretation? I can use some back up here. In electronics and elsewhere sometimes the silicon grease is a problem, it is bad around low voltage switch contacts for example; then the other conductive heat transfer pastes are good. Even here it is good clamping that is important, the layers of material is very thin and changes little. Really good clamping comes from smashing a transistor or IC between to pieces of metal, not using the little bolt hole and a screw. It is more important that the heat transfer material is compliant and touches a lot of surface on both sides. So you get conduction through something more substantial than air and tiny asperities. Maybe even peanut butter is better than nothing. I never found anything about how to use NoAlOx at the Ideal Industries website - can you direct me to that info? If you really really want to put two round conductors together a gas tight crimp is the way to go, It deforms the material and fuses it around any oxides. Don't they crimp those service wiring applications? Screw clamps like Polaris have always bothered me because you can stop short of getting the best connection. A high quality crimper is what you really need. I have my doubts about smearing anything on aluminum is going to stop oxidation. On Tue, Jan 14, 2014 at 12:22 PM, EVDL Administrator <[email protected]>wrote: > On 13 Jan 2014 at 21:06, Michael Ross wrote: > > > Why would anyone want to put an insulating paste in an electrical > > connection when a conductive material could be used instead? > > If you're talking about Noalox and its ilk, try sticking the probes of your > ohmmeter in a glob of that "conductive material" and see what you get. I > think you'll be surprised. > > Same deal, BTW, with computer processor heat and Artic Silver and its > imitators. > > I know, it seems intuitive - add highly heat-conductive metal to the > heatsink grease, and it should conduct heat faster, right? But when you > actually test it, as a computer hobbyist website did years ago, you find > that plain white silicone grease works just about as well, at a fraction of > the price. > > I wish I'd bookmarked that website; now I can't find it. > <tinfoil_hat>Maybe > that's because one of their advertisers suggested that such reports aren't > good for business.</tinfoil_hat> > > FInally, note how you're supposed to use Noalox and similar glop. You coat > the AL wire with it, WIREBRUSH THE WIRE, and then complete the connection. > The idea is that the abrasion removes aluminum oxide, and the Noalox > excludes air so new oxide won't form on the wire inside the connection. > > AL is very often used in electrical service entrance cable, and probably > millions of house main electrical panels have been installed that way with > no problems that I know of. > > David Roden - Akron, Ohio, USA > EVDL Administrator > > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > EVDL Information: http://www.evdl.org/help/ > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > Note: mail sent to "evpost" and "etpost" addresses will not > reach me. To send a private message, please obtain my > email address from the webpage http://www.evdl.org/help/ . > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, "The summer day." To invent, you need a good imagination and a pile of junk. Thomas A. Edison<http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone (919) 631-1451 Cell (919) 513-0418 Desk [email protected] <[email protected]> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140114/6487 e3cf/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
