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Ari
Per my thread about my alternator issue[1], I’ve replaced the voltage regulators in the 310 with the fancy Plane Power substitutes. They seem to work fine. One thing I am a little concerned about is that the over-voltage protection in these regulators works by shorting the enable pin to ground, causing the airplane’s circuit protection for the alternator field switch to open.
The 310 has fuses for the alternator field switches. The failure mode I’m concerned about is an over-voltage from one alternator causing both regulators to blow their fuses, leaving me scrambling to dig out replacement fuses. Murphy’s Law dictates that this will happen when I’m trying to escape icing with the prop heat and every other electronic circuit in the plane turned on, at night, in turbulence, and with frozen-numb fingers due to the heater also deciding not to work that day.
To mitigate that scenario, I am interested in replacing the fuses with Klixon circuit breakers. The Plane Power voltage regulator installation manual calls for a maximum 7.5A breaker, but I’d probably stick with 5A so as not to go bigger than the fuses in the plane. This assumes that 5A breakers will physically fit in place of the fuse holders.
Can an A&P replace a fuse with a circuit breaker and return the plane to service, or does it require the whole IA and FSDO paperwork process?
[1] https://pilotsofamerica.com/community/threads/alternator-issues-suspected-over-voltage.146420/
The 310 has fuses for the alternator field switches. The failure mode I’m concerned about is an over-voltage from one alternator causing both regulators to blow their fuses, leaving me scrambling to dig out replacement fuses. Murphy’s Law dictates that this will happen when I’m trying to escape icing with the prop heat and every other electronic circuit in the plane turned on, at night, in turbulence, and with frozen-numb fingers due to the heater also deciding not to work that day.
To mitigate that scenario, I am interested in replacing the fuses with Klixon circuit breakers. The Plane Power voltage regulator installation manual calls for a maximum 7.5A breaker, but I’d probably stick with 5A so as not to go bigger than the fuses in the plane. This assumes that 5A breakers will physically fit in place of the fuse holders.
Can an A&P replace a fuse with a circuit breaker and return the plane to service, or does it require the whole IA and FSDO paperwork process?
[1] https://pilotsofamerica.com/community/threads/alternator-issues-suspected-over-voltage.146420/