flyrotary@lancaironline.net Mailing List Archive

Chris, The reason your serial link blew is that it probably tried to provide a path for electron flow to a ground (when the EC2 lost its intended grounding wire) - with way too much current for that link to handle. This flow consequently blew the fuseable links I believe Tracy now has installed in the serial link - just to prevent more sever damage to the EC2 from this type of mishap. I don't think you need to exhaust yourself looking for hidden gremlins. The broken ground wire could indeed have caused the problem. When you apply power to a system - four possibilities exist. 1. There will be NO path for ground and NO electrons will flow through the circuit, with no flow - no damage - although the circuit will not work. 2. The electrons will flow through a designated and planned route in the circuit as planned and designed for and all is OK 3. The electrons will find an unplanned path and flow but do no damage 4. The electronic will find an unplanned path and flow causing damage I think in your case, situation 4 applies. Even with a few strands of the ground wire attached it may have provide sufficient flow path to avoid any damage. But, once the last strand separated and the ground wire was gone, then that is probably when the damaged occurred. Some circuits might be able to withstand such misrouting, but while circuits with microchips are quite rugged - they are sensitive to abnormal voltage conditions especially voltage spikes. This abnormal voltage can result from current flowing where it should not. Also even if the current is not high enough to damage a microchip, the unplanned voltage can cause the microchip to treat it as some sort of "unplanned" command for it to do something unintended. Hang it there Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Christopher Barber Sent: Tuesday, July 28, 2009 3:21 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Just livid.....but think anyway. I made it out to the hangar tonight and attempted to reset the EM2. No joy. It would not reset and I could not get it to accept any changes in the MAP table. It is all flat lined. I will likely not get a chance to further investigate wires until I am off on Friday. I did not see anything obvious other than the ground wire that was broken but I shall investigate much further. Of course I am bothered but perhaps more concerned as to the why. I do not want to send the unit back to Tracy again, just to hook it up and it blow again. As I mentioned, the engine was running really well before I started concentrating on the planes finish. I felt pretty good that after a couple of big set backs over the last two year that I was finally on track. As a matter of fact, I felt this has been the first time I have actually been able to use the EM2/EC2 as it should be used since I can't blame the EC2 for coolant in my rotor housing or bad Jeffco in the tanks. So, to maybe ask a couple of obvious questions....could the one bad thick ground wire breaking completely "toast' the EC2? I know it is difficult to make hard and fast rules, but this seems pretty catastrophic for a single wire break. <yikes> Also, if I change to Controller B, will I be looking at the MAP table for the B controller? (if this is flagrantly stated in the manual, I have read past it as I focused on other issues). Okay, I have a few more questions, but my brain is a bit too fried/disappointed to form them right now. <sigh again> So, uh, Tracy, do you have an old EC2 laying around I could buy, that way I can be trashing/working on one while your repair the other. I am not kidding, you have any old stock of EC2's? All the best, Chris Houston > -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html __________ Information from ESET NOD32 Antivirus, version of virus signature database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com