Thank you all for the very useful feedback.
I have updated the wiring accordingly and I am trying to stay as close as possible
to Bob Nuckolls Z-12 philosophy.
My design intent for the endurance bus is the following:
in normal operation, all equipment is powered from the main bus
in case of loss of the main alternator, I want to be able to continue the flight
on the endurance bus with the standby alternator
in case I need to shed the main bus, I want the endurance bus to keep only the
truly necessary loads for safe continuation and landing
So I understand the concern about having too much Garmin equipment on the endurance
bus, especially in a smoke-in-cockpit scenario. That is a very fair point.
My goal is not to make the E-Bus a second main bus, but to preserve the minimum
capability needed to keep control, navigate, communicate, and get on the ground.
Regarding the suggestion to use Hall effect sensors instead of shunts, I may have
misunderstood the intent of that comment. My hesitation is that the AMPLOC
KEY100 have an official end-of-life notice with no recommended replacement listed
by the manufacturer. Since the G3X can also work with a conventional shunt,
I am not sure a Hall sensor is the best path for a new installation at this
point.
I also have a regulator/alternator integration question:
My main alternator is a Plane Power ALY-8520LS, and I plan to use a B&C LR3E regulator.
>From what I understand:
the LR3 field output should go to the alternator F1 lead
F2 on some Plane Power/Hartzell units is either internally grounded or intended
to be grounded externally, depending on configuration
I do not see a clear need for the AUX terminal when using the LR3E as a basic external
regulator
Am I understanding this correctly?
More specifically:
Is the Plane Power ALY-8520LS considered fully compatible with the B&C LR3E?
Should I connect only F1 to the LR3E field output?
Should F2 be grounded, or is it already internally grounded on this alternator?
Should the AUX terminal remain unused in this installation?
My objective is to keep the architecture simple, robust, and as faithful as practical
to the Z-12 concept, while still matching the Garmin/G3X installation requirements.
Thank you again for your time and for reviewing the updated diagram.
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