From shott at snf.stanford.edu Tue Mar 25 15:02:57 2008 From: shott at snf.stanford.edu (shott at snf.stanford.edu) Date: Tue, 25 Mar 2008 15:02:57 -0700 Subject: Problem thermcopoly2 SNF 2008-03-25 15:02:56: Burning smell emanating from "Blower 1" Message-ID: This morning there was a rather non-localized burning smell in the area of wbsilicide and thermcopoly2 that seemed strongest closest to the load end of thermcopoly2. On the back of the load station, I found that there was the same, reasonably strong smell, at the input of "Blower 1" and the whole unit was somewhat warm. I turned off blower one and after a couple of hours, the smell seems to have dissipated. So, I don't know what is inside that box ... squirrel cage or something .... but I suspect that something in there has overheated and fried. Thanks, John From tberg at snf.stanford.edu Fri Mar 28 08:46:20 2008 From: tberg at snf.stanford.edu (tberg at snf.stanford.edu) Date: Fri, 28 Mar 2008 08:46:20 -0700 Subject: Problem thermcopoly2 SNF 2008-03-25 15:02:56: Burning smell emanating from "Blower 1" Message-ID: not around anymore From tberg at snf.stanford.edu Fri Mar 28 08:46:33 2008 From: tberg at snf.stanford.edu (tberg at snf.stanford.edu) Date: Fri, 28 Mar 2008 08:46:33 -0700 Subject: Comment thermcopoly2 SNF 2008-02-02 12:53:42: Enabled for jrjain for continued Ge testing. Message-ID: noted From tberg at snf.stanford.edu Fri Mar 28 08:46:45 2008 From: tberg at snf.stanford.edu (tberg at snf.stanford.edu) Date: Fri, 28 Mar 2008 08:46:45 -0700 Subject: Comment thermcopoly2 SNF 2008-01-22 15:11:56: Ge testing Message-ID: done From shott at stanford.edu Mon Mar 31 20:11:12 2008 From: shott at stanford.edu (John Shott) Date: Mon, 31 Mar 2008 20:11:12 -0700 Subject: Update on burning smell .... Message-ID: <47F1A7D0.4070609@stanford.edu> Fans of thermcopoly2: As you recall, several days ago we experienced a smell near thermcopoly2. At that time, because I could smell it at the intake of "Blower 1", I shutdown power to blower 1 and the smell dissipated over a period of a couple of hours. This afternoon, I disassembled blower 1 and have a somewhat better understanding of what went wrong. Basically, there is nothing in the box but a squirrel cage fan. I found 2 things wrong when I opened the box: it is supposed to be supported by 4 things that I'll call vibration dampers (until I can find exactly what it is in the Grainger catalog). This is a 1/2 diameter, 1/2 inch long length of rubber that has a threaded section attached to each end with probably either 10-24 or 12-24 threads, I think. In any event, all 4 of these have sheared off either due to age or excessive vibration. Moreover, when they sheared off, it allowed one of the electrical contacts (albeit the neutral) to come in contact with the frame and there is clear signs of arcing. This may have been some or all of the smell. I also noticed that the squirrel case is hard to spin ... certainly any other squirrel cage fan has been easy to spin when no power is applied. This leads me to believe that at some point the bearings got toasted. Tomorrow, I will see if I can extract the motor from the housing .... I'm hopeful that I can find a replacement motor because the body of the squirrel case has a somewhat customized flexible-rubber input adapter that looks like it might be a bit tricky to remount to a new squirrel cage housing. In any event, when I order replacement vibration dampers, I'll likely try to order a total of 16 so that we would have them on hand and could, at our leisure, replace them in the other 3 blower units when the occasion allowed. That's what I know about this at the moment but am confident that we can resolve the smell problem if we can find replacement vibration dampers to properly mount the squirrel cage and can also find a replacement motor without bearing problems. Thanks, John