Alt Circuit Breaker Popped Twice Yesterday

[lrobichaux]

It shows a 37 A alternator current spike and numerous lower amplitude spikes.

That short alt current spike was me turning on the pitot heat momentarily.

Did you look at the flight log for the "normal" flight with no CB trip

This was the flight immediately prior to the FIELD breaker pop. In looking at various other previous flights with nearly NO variation in voltage output, it's clear that the loss of regulator control started on this flight, although no CB pop.

It was the "normal" flight data that I think points to an intermittent short of the alternator output, not a regulator fault.

Again, that spike was not an un-commanded spike. It was me turning on, and then off, the pitot heat.

 

[Cactus Charlie]

What heated pitot is fitted to your aircraft? The Garmin GAP probes appear to have a maximum current of 12 A when cold. This current spike was about 24 A.

 

[Cactus Charlie]

This is what a heater test looks like for my GAP 26-10 probe:

 

[lrobichaux]

What heated pitot is fitted to your aircraft?

It's a big ass pitot tube. It's not the standard Garmin probe on the FX-3s. Sadly, this is also why the X/NXCubs do not have AOA connected on the G3X. I've considered having a Garmin pitot tube installed just for the AOA.

 

[Cactus Charlie]

It's a big ass pitot tube. It's not the standard Garmin probe on the FX-3s. Sadly, this is also why the X/NXCubs do not have AOA connected on the G3X. I've considered having a Garmin pitot tube installed just for the AOA.

If it has a part number marked on it I'd be curious what it is. I can't find any heated pitot probes that draw near 24 A and the CB is only rated at 20 A.