Originally Posted by
cub builder
per AC43.13-1B Chapter 11 (Electrical) section 51, paragraph b.
Automatic reset circuit breakers, that
automatically reset themselves periodically, are
not recommended as circuit protection devices
for aircraft.
It doesn't say illegal, but it does say not recommended. However, if memory serves correctly, the two Stinson Voyagers I owned years ago were both equipped with automatically resetting circuit breakers.
Think about this situation. If a device smokes when power is applied, you may want the capability to completely and permanently remove power. I have run across that situation with a solid state wig-wag controller. The switch that turns on the wig-wag device gets it's power from the wigwag controller itself. When it failed, it had both smoke and sparks, that continued until power was completely removed. If power was re-applied it would start sparking and smoking again. Since the wigwag controller supplied the power to the switch, that meant the power had to be removed ahead of the switch via either circuit breaker or shutting off the master switch. You might say that's a less than ideal wigwag controller, but I know for a fact there are a lot of these very light weight wigwag controllers flying around in both certificated and Experimental Aircraft. There may also be other similar devices, and sometimes these types of failures can't necessarily be anticipated, which is why you may want the ability to pull a breaker or otherwise disable a circuit.
-Cub Builder