Kevin. that was an odd question my friend. What benefit do you have of a catastroph failure photo? Sure, I have all kinds of photo material, but to scan hundreds of reports to find a particular photo takes time. Instead I go directly to your question. It depends (Doug TM) on the kind of circuitry you have. Resistive? Inductive? Current limitation? Lead material? Heat paths? Lead cross section area? Lead length? etc Let's compare with a gold bond 1 mil wire. Despite it's thinness, it's capable of taking 6 amperes DC for some milliseconds. Then imagine a component lead!! Maybe a hundred amperes instantly. Overcurrent can appear as a) a inrush current high enough to rise the resistive current so fast that you melt the lead within milliseconds. The temperature reaches thousands degrees and the hottest part of the lead vaporises. Typically, it acts like an explosion. Melt metal spreads around, oxides and soot covers the surroundings and there is a smell of burnt material. The voltage drops, some major fuse breaks and nothing more happens. This is the most positive scenario. What is far more dangerous is if the voltage does not drop (it can increase instead, inductive load) but continues to feed, arcing can start and put fire to surrounding components. So, my answer is: if the overcurrent disintegrates a lead, there will NOT be left a smooth and clean metal, because that is against all physical laws. With one exception. Theoretically, if the short circuit current is 'unlimited' and dt/T is 'zero' , the lead may break by electromechanical forces rather than by thermal causes. The inventors have tried for may years to design fuses that behave like that. If your leg broke by overcurrent and is still smooth and clean, hurry , take patent . My two amperes Inge -------------------------------------------------- From: "Glidden, Kevin" <[log in to unmask]> Sent: den 20 May 2010 19:53 To: <[log in to unmask]> Subject: [TN] Visual clues of over-current for leads > Hello, > > Can anyone describe or provide photos of what one might expect a lead that > has been subjected to such a high current that it damaged (burned? > disintegrated?) the lead? > > Would you expect to see charring all the time? Is it possible to see > smooth, clean surfaces with just a section of the lead missing? > > > ______________________________________________________________________ > This email has been scanned by the MessageLabs Email Security System. > For more information please contact helpdesk at x2960 or [log in to unmask] > ______________________________________________________________________ > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using LISTSERV 15.0 > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt or (re-start) delivery of Technet send e-mail to > [log in to unmask]: SET Technet NOMAIL or (MAIL) > To receive ONE mailing per day of all the posts: send e-mail to > [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: http://listserv.ipc.org/archives > Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 > for additional information, or contact Keach Sasamori at [log in to unmask] or > 847-615-7100 ext.2815 > ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------