EFII power requirements, bus manager specs, and other questions

[rmartingt]

Posted as a separate thread because it doesn't involve VP-X and so it'll be available for reference...

I am in the planning stages of my electrical system and am planning on using the full EFII package with the bus manager. However, I'm looking for some information and can't find it in the online manuals.

1. I can't find any information about current limitations for the main and essential buses on the bus manager. What is the maximum current allowed on each?

2. I'm trying to find actual (average) current draw for a dual ECU EFII system so I can plan my batteries and alternators. What should I use as a steady-state average?

3. Is it possible to shut off only the main power bus without using the emergency power switch (e.g. operate main and endurance buses separately)?

4. Do you have recommended ways of tying in a ground power source for charging, avionics operation, etc?

5. How much current do the start battery selector switch, start switch, pump selector switch, ECU selector, and key switch require? I'd like to use something other than toggle switches elsewhere and want these to match.

[jcaplins]

1.
main: 40 A max continuous
essential: 30 A max continuous
(Page 4 of the manual)

5.
I believe these are very low current only used to switch relays; they are only 22 awg wires.


That's all I know.

[sbalmos]

2. At one time, I believe Robert told me in an email that the ECUs themselves are ~0.1A each, the ignition coils and fuel pumps are ~5A. Ultimately, in my primary power bus diagramming, I had calculated that the max continuous for the ECUs, ignition coils, and fuel pumps was 10.2A.

3. Just put a switch capable of handling 40A, or maybe another contactor, between the main bus output of the bus manager and the input of your bus bar. Translation - no, nothing in the Bus Manager itself.

4. Err... I would think this would be "upstream" of the Bus Manager in your power system layout, around where you would plan the battery/alternator feeds?

[miyu1975]

Good questions. I recommend asking Robert. He was very helpful in answering all my questions either by phone or email.