Over Voltage Protection?

[jjacky]

Hi All...I'm laying out the electrical system for the Highlander/Rotax912 and considering installing the B&C Over voltage protection kit. It crowbars (blows) the Alternator circuit breaker if the the alternator voltage gets above 16 Volts or so. I'm concerned because of the sensitivity of Lithium Ion batteries to over voltage. But! there seems to be a lot Aye's and Nay's concerning the need for this protection. Are any of you using?....Thoughts? Thanks!

[gkremers]

I have used this drawing for 3 different Rotax 912 installations. It does use the over voltage protection. Pretty simple design but very functional.

BTW.. I also used the 2-10 switch for BAT and BAT/ALT and 2 toggle switches (1-3) for the right and left ignition, push button start.

Gary

[SuperFly]

I have my airplane wired exactly according to Bob Knuckolls Z16 drawing,(as Gary posted above) with the exception of the low voltage warning module. I have an Dynon D180 and it will warn you of low voltage (setable parameters), as I think most all EFIS screens will do. I have read some opinions that say dumping the load quickly on the Rotax alternator could cause damage to it. My thoughts were, it is cheaper to damage and replace the alternator than to replace all the electronic gizmos in the panel if the voltage were to run away. The engine would continue to run on battery power for the duration of battery capacity in that event. (Ideally giving enough time to find a suitable landing spot).

Now, I can not speak to the effectiveness of the system in an actual event, and God willing, I never will, but it is a pretty inexpensive, lightweight, and fool-resistant option if it were ever to occur.

Also, I am sure it has happened, but it seems to be a pretty rare problem with the 912s. It seems (at least to me) that you just never hear about it being a problem.

My $0.02... Probably over priced too.

[Tralika]

You might want to take a look at the EarthX batteries. They have a chip built in to protect the battery from both over voltage and over discharge. It also allows the battery to be fully charged with an engine alternator. Pretty spendy but you get what your pay for.

http://earthxmotorsports.com/

[jjacky]

Great...Thanks-A-Bunch Guys.

[gkremers]

Ben,
Good point on the low voltage lamp. I didn't hook it up either. The GRT EIS takes care of that. If anyone is looking for any of the components in the drawing just go to B & C Specialty Products.

http://www.bandc.aero/index.aspx


Gary

[SheepdogRD]

Pictures of the panels you built would be a great help, too, guys.

Thanks . . .