EMS Issue

[Tackdog]

Hi Guys, I'm hoping you can offer some advise - some info for me to pass onto the workshop. My aircraft is in with the avionics guys having a full skyview HDX package installed. During the first engine run, all things were fine then on shut down the EMS failed - was returned for repair. Upon being returned and re-installed it failed again. The avionics guys checked the alternator and after suspicion of the internal reg being faulty, it was removed and rebuilt and re-installed. As they were now concerned that the alternator may be causing the EMS failure, they presented the below to me.....

(we ran the aircraft with the ems disconnected to check voltages. It was noted that on switching off the alternator the voltage increased significantly ( at one stage 34 volts was noticed). The alternator field wire was repositioned from the alternator relay to the load side of the battery relay. Testing continued with again the alternator voltage going high when switched off but no spike in voltage was noticed at the bus. As the dynon ammeter is between the alternator and the alt relay i have concerns , could you go back to dynon and find out what the original failure of the ems was caused by and more specifically was it connect to any sensor.)

Any thoughts at all?

Thanks

 

[kurtfly]

Check the following posting. It looks like you are experiencing the same thing I experienced when I had a regulator failure. See post #9 for a schematic to help protect against this. But anytime you connect the shunt between alternator and circuit breaker you may expose the shunt / EMS to very high voltages if regulator fails or improperly wired.

http://dynonavionics.com/cgi-bin/yabb2/YaBB.pl?num=1482532338

 

[Tackdog]

Thanks for the advice Kurt, greatly appreciated! Would any Dynon techs like to respond please?

Cheers

 

[Dynon]

Know that our primary technical support channels are via phone and email, and so following up with the support team directly (there are a few of us that respond on the forum here, and we're a mix of senior product, engineering, and marketing folks).

So it looks like our repair team is looking into this with our engineering department as of today. But correlating what you've said with what we've seen, it sounds like you might have had an electrical issue in the aircraft (voltage regulator) that was big enough to do some damage to the EMS module despite the internal protections.

 

[Tackdog]

Thanks once again. I'll eagerly wait for your tech dept response.

Cheers