Re: Alt Field Circuit Breaker Popping

Jay Scheevel

50 amp breaker is handling the current out from the alternator. It is only active when the alternator is spinning otherwise current from the alternator is zero. Battery charge plus electric items is probably 35 amps right after takeoff. If engine is not turning or field voltage is zero, then all current is coming from the battery.


Sent from my Verizon Wireless 4G LTE DROID

"Corbin Geiser c_geiser@... [Q-LIST]" <Q-LIST@...> wrote:


Update:  I’ve located a 50amp breaker labeled MAIN.  I turned on Master, electronics come on, and then I pulled the 50amp breaker.  Nothing turned off.  I’ve removed the breaker and would like to know how to test to confirm if it’s working or not.  

Should all electronics turn off if I pulled the MAIN breaker?


On Jul 29, 2019, at 11:59 AM, Rick Hole r.hole@... [Q-LIST] <Q-LIST@...> wrote:


An open alternator output, for example 50a breaker tripped or disconnected wire could cause the field breaker to blow only if the regulator suppling full voltage to the field draws enough current to trip the 5a field breaker. This should not be possible but if the 5a breaker is old and tired and, say, tripping at 3a your could see it trip. I have never seen this happen though. 

Don’t overlook wire fault as a cause, insulation worn through and he wire touching something grounded etc. 

Rick Hole
Email: r.hole@...

On Jul 29, 2019, at 10:23 AM, q2pilot@... [Q-LIST] <Q-LIST@...> wrote:


Ok, great news.

Now disconnect the Field wire from the back of the alternator and leave hanging.
Does the 5A break still blow?  If it does it's a bad regulator.  If it doesn't blow now, then we may have a shorted field in the alternator.
: )

Join to automatically receive all group messages.