Aux Bus

[flyboy0681]

During my takeoff roll today the Aux Bus circuit breaker popped. This caused the JPI to shutdown and the GTN to flicker for a few seconds. Would a voltage surge typically cause this?

[OR75]

I would have thought the JPI would be on the main bus rather the aux

maybe a loose connection  ? I would worry about it if it happens again 

[PT20J]

The Aux Bus breaker protects the wire between the breaker and the bus that feeds the breaker/switches for lights, etc. on the pilot's lower panel. The bus bar that connects the switches does not have a lot of clearance from the panel. I would check it for a short. That's a pretty large breaker and I doubt a momentary overvoltage would trip it.

[flyboy0681]

It hasn’t happened in the subsequent flight, so at this point it remains a complete mystery. 

[PT20J]

1 minute ago, flyboy0681 said:

It hasn’t happened in the subsequent flight, so at this point it remains a complete mystery. 

I'd look at the wiring on the back of the switches. Something may be very close to touching. Also, I'd remove the glare shield and look at the back of the circuit breakers. On mine, there were thin strips of insulating material separating breakers on the tightly packed top row and if that is missing or damaged it could cause a short.