Schematic - Distribution

[MolsonB]

I'm starting my wiring schematics and wondering what you guys think so far. It's pretty basic, but starting with automatic redundancy built in. Fail-over without human intervention. My setup is dual batteries, single alternator and fully EFI engine (Mazda Rx8). There is talk of adding a secondary generator inside the PSRU, but that's down the pipeline.

I'll have three switches to control the power buses.

S1.1 - Main = On/Off
S1.2 - Backup = On/Off
S1.3 - Link = On/Auto/Off *On is an override to connect both buses

The Smart Battery Isolator (Robust, inexpensive 12V 150+amp smart battery isolator and smart split charge relay for RV, car, and truck applications) will connect both buses (aka. charge both batteries) when it senses the alternator is >13.4V (on). When it's just batteries (<12.6V), it will isolate the batteries from each other. You can manually override using the switch Link to "On" if you want both batteries for cranking, or if you lost the alternator while flying and want the amps from both batteries combined.

Starting procedures:

1. Flip the switch Main and Backup to "On" and Link to "Auto".
2. Verify Main & Backup buses have Volts
3. Start Engine
4. Once the alternator turns on, verify Link Led showing the buses are connected
5. Turn Off Main bus
6. Verify Backup bus is still powering the essential items
7. Turn On Main bus

Automatic Fail-overs:

• Main bus fails, Backup bus will continue to operator the essential items. EFIS will tell me it's missing Power from Main bus.
• If either battery fails in-flight, both buses will continue to be powered by alternator + other battery. I won't know until the alternator is turned off, if any batteries are fubar. Which I'll be on the ground by then.
• If main battery can't crank over engine, I can turn on the backup battery to help.
• If I left a bus on overnight and battery drains, the isolator will keep the other battery full.

Note:

• The reason I put the Alternator before the main solenoid, so if I turn off the main, it won't keep on powering the main bus.
• The switch Link has an Off position which will disconnect the ground for the microcontroller on the solenoid to save that parasitic drain.
• The Main Bus is VPX-Pro which will power everything, the Backup Bus is a fuse block that will just power the essentials on standby.

I'll work on this tomorrow, but my idea is any essential item that has two separate power inputs (GRT HXr) will have power from both buses. Any item that only has 1 power input, will get a NC/NO relay. When the main bus has power, the relay stays off and the device gets power from the main. If the Main bus losses power, the relay will activate and pull power from the backup bus.



-Matt

 

[12notes]

 

[MolsonB]

 

[user 4289]

 

[MolsonB]

 

[Tiger Tim]