N546RV
Well Known Member
My questions will continue until morale improves...
First, for reference, the aforementioned Z-13 schematic, since I'm sure few of us can recall these things on-demand (click for larger image):
I'm planning an IFR-capable airplane with dual SDS CPI2 electronic ignition - so keeping the electrons flowing is something I care about. (side note: the CPI2 and EFISs will have dedicated backup batteries)
One thing I like about the Z-13 setup is that the SD-8 feeds in ahead of the master contactor - so even a failure of that component doesn't force you onto solely battery power. It also provides a quick load-shedding ability without giving up generated power.
Thing is, the SD-8 is a bit on the light side for my backup use. If I want to continue flying without immediately leaning on backup batteries, just one side of the CPI2 and a single EFIS screen puts me over budget on amps. If I immediately lean on backup batteries, then they become the limiting factor of my endurance, and there's hardly any need for a backup alternator then.
So something like a B&C 410-H seems more in line with what I'm looking for; 20 amps gives me a lot more headroom, and I could run one CPI2 side, one Skyview screen, plus enough other things to make continued flight not a huge deal (com radio, xpdr...trim...).
Thing is, I don't think I've seen any proposed schematics with a Z-13 placement of the standby alternator, but using an actual alternator (as opposed to a PM unit like the SD-8). I'm wondering if there's a problem with this idea that's not obvious to me? Or is this just an uncommon idea?
A very simplified example of the layout I'm talking about:
First, for reference, the aforementioned Z-13 schematic, since I'm sure few of us can recall these things on-demand (click for larger image):
I'm planning an IFR-capable airplane with dual SDS CPI2 electronic ignition - so keeping the electrons flowing is something I care about. (side note: the CPI2 and EFISs will have dedicated backup batteries)
One thing I like about the Z-13 setup is that the SD-8 feeds in ahead of the master contactor - so even a failure of that component doesn't force you onto solely battery power. It also provides a quick load-shedding ability without giving up generated power.
Thing is, the SD-8 is a bit on the light side for my backup use. If I want to continue flying without immediately leaning on backup batteries, just one side of the CPI2 and a single EFIS screen puts me over budget on amps. If I immediately lean on backup batteries, then they become the limiting factor of my endurance, and there's hardly any need for a backup alternator then.
So something like a B&C 410-H seems more in line with what I'm looking for; 20 amps gives me a lot more headroom, and I could run one CPI2 side, one Skyview screen, plus enough other things to make continued flight not a huge deal (com radio, xpdr...trim...).
Thing is, I don't think I've seen any proposed schematics with a Z-13 placement of the standby alternator, but using an actual alternator (as opposed to a PM unit like the SD-8). I'm wondering if there's a problem with this idea that's not obvious to me? Or is this just an uncommon idea?
A very simplified example of the layout I'm talking about: