John and Larry, thank you for your input. I totally appreciate it, which is 
why I reach out to the group...First things first... I will explain what I know 
from my observations as a layman. 

Here is the trial-and-error method that I used to find the fault... 1. I 
removed all devices connected to the Avionics switch (lit with an LED 
indicator) which is the culprit.2. I disconnected the wire supplying power to 
that switch (the switch status is off) from the power buss. 3. Then turned the 
switch on 4. I touched the wire from the switch to the buss bar5. I observed an 
arc, and the wire became hot (as in heat).6. No breakers tripped though it was 
connected to a 5A breaker7. When I removed the wire from the buss, again a 
small arc followed. 8. While the switch was on, I observed the battery drain 
from a normal 12+ Volts to as low as 10.5V9. I removed the switch and replaced 
with a common toggle switch (rated at 10A)10. I reconnected the circuit to the 
buss, and I did not observe arching nor did the wires get hot.11. I kept 
feeling the wire for heat for a few minutes before reconnecting devices one at 
a time12. After I reconnected all devices, I turned them on one at a time to 
see if I still had a problem.13. All devices came back online without any 
problems14. The voltage as recorded by the EMS indicated a stable 12.5VDC with 
no deterioration.
Today, I went out to the airport and ran the engine, turned on all of the 
instruments and between the battery and the alternator, I was able to sustain a 
steady 12.5VDC. I ran it for about 5 minutes and shut it down. I reached under 
the panel and all wires felt normal (no heated wires).
I hope that helps some.
Luis  
    On Friday, August 30, 2024 at 10:00:47 AM CDT, Larry Flesner via KRnet 
<krnet@list.krnet.org> wrote:  
 
  

 
 On 8/30/2024 9:34 AM, John Gotschall via KRnet wrote:
  
 
Hi all, 
  I read something about an avionics power connection arcing upon contact 
during 
troubleshooting.+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  
Something to support your observations, I learned early on in my electronics 
education,  working on crypto equipment in the USAF,  and 33 years working on 
office equipment for Xerox, that if you don't know what normal operation is 
you're not really troubleshooting, you're no different than a pig rooting for 
an acorn.  They often find the acorn but they also spend a lot of time rooting 
and find nothing. 🙂
 
Larry Flesner

  -- 
KRnet mailing list
KRnet@list.krnet.org
https://list.krnet.org/mailman/listinfo/krnet
  
-- 
KRnet mailing list
KRnet@list.krnet.org
https://list.krnet.org/mailman/listinfo/krnet

Reply via email to