rdamazio
Well Known Member
Hi all.
I've started designing the electrical system for my -10, and I'd love feedback on it.
This is the overall architecture - it's a dual-battery dual-alternator system since I plan to use EFII's electronic ignition/injection (not a wiring diagram - CBs, actual pins, etc. not depicted, some switches are "virtual" inside the VP-X, busses are symbolic and each device may be connected to different VP-X pins, etc.):
Architecture diagram: https://drive.google.com/open?id=1fvotSDTnyId0gyroQouL12FvRwGdhQzJ
And this is the load analysis I did - the numbers came back kinda high (yeah, I'm putting a lot of stuff in, but still...). (comment are enabled there, so feel free to comment there directly as well):
Load analysis: https://docs.google.com/spreadsheets/d/1IkQveNvuCesB5Begc34UOPcRjaaZB_e8qhmC5toqPlY/edit?usp=sharing
I'm especially uncertain about the dual batteries and alternators setup, with two PPSs:
Any comments or suggestions are welcome. (how badly am I overthinking this? )
Thanks!
Rodrigo
P.S.: I've read the AEC but won't promise to remember everything in there.
I've started designing the electrical system for my -10, and I'd love feedback on it.
This is the overall architecture - it's a dual-battery dual-alternator system since I plan to use EFII's electronic ignition/injection (not a wiring diagram - CBs, actual pins, etc. not depicted, some switches are "virtual" inside the VP-X, busses are symbolic and each device may be connected to different VP-X pins, etc.):
Architecture diagram: https://drive.google.com/open?id=1fvotSDTnyId0gyroQouL12FvRwGdhQzJ
And this is the load analysis I did - the numbers came back kinda high (yeah, I'm putting a lot of stuff in, but still...). (comment are enabled there, so feel free to comment there directly as well):
Load analysis: https://docs.google.com/spreadsheets/d/1IkQveNvuCesB5Begc34UOPcRjaaZB_e8qhmC5toqPlY/edit?usp=sharing
I'm especially uncertain about the dual batteries and alternators setup, with two PPSs:
- Cross-feed: I'm understanding that the EFII Bus Manager handles cross-feeding for me - do I still need a cross-feed contactor in that case?
- External power: I connected the external power plug to only one battery, since it can feed both busses/systems (but did add a switch to isolate this)
- Dual VP PPSs: I ended up with two Vertical Power PPSs to avoid having a lot of solenoids all over the place, and as a way to implement EFII's two-battery starter selection. Is there an easier way?
- Battery overcharging: the plan was to use two EarthX ETX900s, but with two alternators (70A+30A) I'm afraid that, if the other battery somehow dies, both alternators will be (over)charging the single battery left with ~100A, which is above the EarthX's limit of 80A - what's the common way to prevent that? Does the voltage regulator prevent it automatically, or do I need some way to shut down the second alternator?
- Alternator capacity: I understand most people pick 60A alternators, I changed to 70 because that's what the load analysis (below) shows I may have >60A as max continuous - is that the right way to think about it? Or just I just assume that I'll be shedding load anyway if one of the alternators fails, and thus 60+30 (or even less) would be enough?
- Battery in the back/front: Was thinking of maybe installing one battery in the back and one on the cockpit side of the firewall (ETX900-VNT) - this also makes me have only one battery contactor on the back, since the PPS recommends a remote contactor if the battery is remote (which makes sense). Any arguments either way? (also, for anyone that has installed a ETX900-VNT - how did you route the vent lines?)
- EFII ignition: For the ignition redundancy (since that's the only component that's not dual in the EFII system), I placed a relay to switch it between power sources - have others done the same?
Any comments or suggestions are welcome. (how badly am I overthinking this? )
Thanks!
Rodrigo
P.S.: I've read the AEC but won't promise to remember everything in there.