Electrical Issue Rotax 912 ULS - Zenith Aircraft Builders and Flyers2024-03-29T07:04:30Zhttps://zenith.aero/forum/topics/electrical-issue-rotax-912-uls?feed=yes&xn_auth=noI had a similar issue, strong…tag:zenith.aero,2017-01-16:2606393:Comment:5457442017-01-16T01:21:44.055ZAdam Messerhttps://zenith.aero/profile/AdamMesser
<p>I had a similar issue, strong smell of burning insulation, during takeoff. This resulted from poor electrical connections between the stator and the regulator, so that the insulation was melting. High current demand with high rpm (and corresponding alternator output) from having switched on all of the electrical systems (avionics, strobes, landing lights, etc) early in taxi (depleting battery) caused this. I replaced the cabling and connectors, and modified my takeoff checklist to avoid…</p>
<p>I had a similar issue, strong smell of burning insulation, during takeoff. This resulted from poor electrical connections between the stator and the regulator, so that the insulation was melting. High current demand with high rpm (and corresponding alternator output) from having switched on all of the electrical systems (avionics, strobes, landing lights, etc) early in taxi (depleting battery) caused this. I replaced the cabling and connectors, and modified my takeoff checklist to avoid powering up electrical systems until I was ready to roll. I will say that the two-year duration of your issue makes my scenario unlikely, but thought it would be worth mentioning in any case.</p> Definitely ground the regula…tag:zenith.aero,2017-01-13:2606393:Comment:5456502017-01-13T00:35:09.737ZTimothy D. McCallhttps://zenith.aero/profile/TimothyDMcCall
<p></p>
<p>Definitely ground the regulator case, thanks Bob. The smoke you smell may be a piece of your avionics trying to deal with high supply voltage.</p>
<p></p>
<p>Tim</p>
<p></p>
<p>Definitely ground the regulator case, thanks Bob. The smoke you smell may be a piece of your avionics trying to deal with high supply voltage.</p>
<p></p>
<p>Tim</p> Assure that a separate ground…tag:zenith.aero,2017-01-12:2606393:Comment:5455062017-01-12T21:59:27.892ZBob Hartunianhttps://zenith.aero/profile/BobHartunian
<p>Assure that a separate ground wire goes from regulator case to ground bus. Don't rely on structure grounding.</p>
<p>Assure that a separate ground wire goes from regulator case to ground bus. Don't rely on structure grounding.</p> I agree, sounds like the regu…tag:zenith.aero,2017-01-12:2606393:Comment:5453312017-01-12T08:17:15.029ZCharles Millerhttps://zenith.aero/profile/charlesmiller
<p>I agree, sounds like the regulator is working. I'm not familiar with the wiring but will assume when the alternator is switched off the battery is disconnected allowing the capacitor to function as a small accumulator. If that is the case there may not be enough load on the regulator to keep the system voltage from spiking and over charging the capacitor. The addition of a load resistor 25 ohm across the capacitor may stabilize the regulator during the "off " state. Still doesn't help…</p>
<p>I agree, sounds like the regulator is working. I'm not familiar with the wiring but will assume when the alternator is switched off the battery is disconnected allowing the capacitor to function as a small accumulator. If that is the case there may not be enough load on the regulator to keep the system voltage from spiking and over charging the capacitor. The addition of a load resistor 25 ohm across the capacitor may stabilize the regulator during the "off " state. Still doesn't help the main issue, burning smell. Like Tim said, inspect wiring and connections. If something is getting hot enough to smell it should show signs of overheating.</p>
<p></p> I'd look for a loose ground.…tag:zenith.aero,2017-01-12:2606393:Comment:5453262017-01-12T06:45:37.274Zdavid shraderhttps://zenith.aero/profile/davidshrader
I'd look for a loose ground. Engine to airframe, alt., or dynamo, check regulator too. If you can smell it during flight I promise you can see it. If there is enough current flow to cause a burning smell an no breaker/fuse pop my money is on a ground
I'd look for a loose ground. Engine to airframe, alt., or dynamo, check regulator too. If you can smell it during flight I promise you can see it. If there is enough current flow to cause a burning smell an no breaker/fuse pop my money is on a ground Art
It seems to me that your…tag:zenith.aero,2017-01-12:2606393:Comment:5455652017-01-12T03:36:44.754ZTimothy D. McCallhttps://zenith.aero/profile/TimothyDMcCall
<p>Art</p>
<p>It seems to me that your regulater is working. The charging system is working hardest just after take off. This is when it is recharging the battery from engine start etc. If its going to get hot that would be the time. Check for properly sized wire and good crimps on wire terminals. Look closely at connectors for discoloration and other signs of heating.</p>
<p>The stray voltage you were reading may of been a charged capacitor.</p>
<p></p>
<p>Tim</p>
<p></p>
<p></p>
<p>Art</p>
<p>It seems to me that your regulater is working. The charging system is working hardest just after take off. This is when it is recharging the battery from engine start etc. If its going to get hot that would be the time. Check for properly sized wire and good crimps on wire terminals. Look closely at connectors for discoloration and other signs of heating.</p>
<p>The stray voltage you were reading may of been a charged capacitor.</p>
<p></p>
<p>Tim</p>
<p></p>
<p></p> Hi
Did you test the capacitor…tag:zenith.aero,2017-01-12:2606393:Comment:5455602017-01-12T02:05:55.159ZFrançois Balauxhttps://zenith.aero/profile/FrancoisBalaux
<p>Hi</p>
<p>Did you test the capacitor and its connection? That could explain the 37 volts.</p>
<p>How is the regulator mounted on the airplane?<br/>Regards,</p>
<p>Francois</p>
<p>Hi</p>
<p>Did you test the capacitor and its connection? That could explain the 37 volts.</p>
<p>How is the regulator mounted on the airplane?<br/>Regards,</p>
<p>Francois</p>