Wiring schematic

[Kitfox Pilot]

Does the circled part of the schematic mean pin for pin wiring on the switch? Both grounds go to the center pins and so on? The bottom wire coming up is a ground I have the symbol covered up with the switch.

Reason I ask is the rotax regulator A needs grounded to airframe and battery power provided to run the ecu to start by the temporary side of the switch. I can't see how it grounds with both grounds going to the center posts. I'm sure I'm not understanding something simple.

Thanks for any help.

[Kitfox Pilot]

Does the circled part of the schematic mean pin for pin wiring on the switch? Both grounds go to the center pins and so on? The bottom wire coming up is a ground I have the symbol covered up with the switch.

Reason I ask is the rotax regulator A needs grounded to airframe and battery power provided to run the ecu to start by the temporary side of the switch. I can't see how it grounds with both grounds going to the center posts. I'm sure I'm not understanding something simple.

Thanks for any help.




I finally figured it out, I take pics to literal , haha.

[Eric Page]

Well, you're smarter than me! I wrote up a lengthy reply explaining why it can't work as drawn, but I guess I won't post that now...

I just don't see how the START POWER and BACKUP BATTERY functions can both be accomplished -- in the way Rotax specifies in the 912iS installation manual -- with one DPDT switch.

If you can explain it to me I'd be obliged, as I've got that installation kit coming so I'll need to figure it out eventually.

[Kitfox Pilot]

Eric, pg 52 shows it better, to me anyway. The kfox drawing is not right IMO.
I can't get the page to copy to post here so maybe you can.


https://www.rotax-owner.com/pdf/IM_915iA_Series_Ed0_Rev3.pdf

[Eric Page]

The kfox drawing is not right IMO.
Well, we agree on that!

The relevant parts of of the diagram on pg 52 of the 915iS manual are pretty much identical to the page I posted from the 912iS manual. I just don't understand how Kitfox accomplishes, with a single DPDT switch, what Rotax does with two DPST switches.

How did you do it?

[Kitfox Pilot]

I cheated I guess , ground to center post and 12v backup power to other center post. Temporary side pressed puts power to post 2 on rotax wiring and switch hold position supplies post 1 with power if alts fail.
Not perfect like the pic but it serves the purpose I'm after to start the engine and run it if all else fails.

[Eric Page]

OK, that was the only way I could see to make it work with that switch too.

My concern is that Rotax specifies separate 30A breakers for those two functions, but the DPDT switch forces an installer to use one breaker for both. Without knowing how the engine's black boxes are powered internally, we don't know if Rotax had a very good reason for using separate breakers.

I'd sure like to know why Kitfox is doing it this way, and why they show two breakers when there's no way to wire two with their supplied switch. Guess I'll have to ask them when the time comes...

Thanks, Harlan.