Hi Peter, That's what I thought too until I actually saw one up close. There was no bi-metal strip. Perhaps there are two kinds - fused ones and circuit breaker ones. I have not yet managed to find a site which describes the latter in a form which looks anything like what I've seen. Sean On Fri, Jun 20, 2008 at 12:09 AM, Peter Todd wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On Thu, Jun 19, 2008 at 11:47:33PM -0400, Sean Breheny wrote: >> Hi Adam, >> >> Thanks - I will be looking over those sites. I am amazed that people >> sell 50MVA transformers on the used market!! I guess it makes sense >> (after all, they sell airliners used). >> >> Sean >> >> >> On Wed, Jun 18, 2008 at 10:42 PM, M. Adam Davis wrote: >> > My first attempt would be to look for power distribution manufacturers: >> > >> > http://www.google.com/search?q=power%20distribution%20equipment >> > >> > In this case the first link is to >> > http://www.tucsontransformer.com/ >> > >> > They have pictures for a variety of (used?) equipment, which is useful >> > in and of itself. >> > >> > Looking further, though, they list the manufacturer of each piece, >> > some of which are: >> > http://www.uscopower.com/ >> > http://www.royalswitchgear.com/ >> > http://www.southernstatesllc.com/ >> > http://www.morpac.com/ (Also equipment for stringing lines) >> > http://www.sandc.com/ >> > http://www.powellind.com/products_page2.asp?MenuCategory=2&MenuPosition=1 >> > http://w1.siemens.com >> > http://www.abb.com/ >> > http://www.ge.com/products_services/electrical_distribution.html >> > http://www.gelearningcentral.com/lms/login/index.php <-- Learning center...? >> > http://www.hubbellpowersystems.com/ >> > >> > I imagine if you do that with a few distributers (or just looked at >> > the nameplates of equipment you pass) then you'll gain a much larger >> > inventory of links to manufacturers, most of whom post whitepapers, >> > app notes, etc. >> > >> > -Adam >> > >> > >> > >> > >> > >> > On Wed, Jun 18, 2008 at 9:40 PM, Sean Breheny wrote: >> >> Hi all, >> >> >> >> Can anyone point me to a web site which describes details about the >> >> power distribution network (preferably in the US)? Specifically, I'd >> >> like to be able to identify some of the equipment commonly seen on >> >> utility polls and in substations. I'm not looking for a map of the >> >> actual network (i.e. something which is likely not published for >> >> security reasons) but just detailed descriptions about the different >> >> components, what they look like, how they work, etc. >> >> >> >> I am familiar with the basics but recently I came across some >> >> equipment which had been left (unenergized) at the base of a poll. One >> >> of the items was what I now know is called a fuse cutout. I had often >> >> seen them at a distance and assumed they were circuit breakers. Upon >> >> looking at it closely, I couldn't identify any circuit-breaker >> >> mechanism - it looked like a simple switch. Searches for "switch" and >> >> "circuit breaker" didn't yield any relevant results. I finally >> >> stumbled upon the correct term and then found drawings and >> >> explanations. I'd like to do the same for some other items I've seen >> >> but have not known what they are. > > My understanding of those is that the blades holding the free end of the > switch arm are designed to expand via a bi-metalic strip-type system > allowing the arm to drop free. They are then sized to heat up > appropriately at the correct breaking current, which considering the > fairly robust construction gives you an idea of how many amps they are > rated for, a lot. :) > > Linemen then use a long fiberglass pole with a little hook on the end to > physically move the arm back into place via the round eye at the end of > the arm to reset the breaker. > > - -- > http://petertodd.org 'peter'[:-1]@petertodd.org > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.6 (GNU/Linux) > > iD8DBQFIWy2S3bMhDbI9xWQRAriQAJ9FXJWtMeV0DLzRNLadm3GNEnfCYgCfRpAg > td3KYtx9qap16D7LRcdA8G0= > =bfhS > -----END PGP SIGNATURE----- > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist