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-   -   RV-14 Electrical Diagram (http://www.vansairforce.com/community/showthread.php?t=167454)

mulde35d 01-04-2019 01:32 PM

RV-14 Electrical Diagram
 
With all the discussion on lighting and electrical noise I thought I would post the primary power and G3X pinout diagram that I created over the course of about 6 weeks of sitting in hotel rooms bored out of my mind. This is still under revision as I actually build it, but while the pictures are only JPEG I would be happy to email the full working Visio product or a read only PDF to anyone who is interested (PM me with your email address and specify which file type you would like). I created this from scratch while referencing an electrical drawing that was produced by a professional company to give me some ideas on how to lay things out in a clear manner. Hence why it may look like a paid for product, but is purely an original creation. The wire numbering scheme is also original and has a decoding method to the madness that should help me identify wires quickly in the aircraft should I find problems once in flight.

I am also open to any input from any electrical guru's in the house as most of this was self learning from the baseline installation documents with a couple calls to Garmin for some detailed pinout instructions. Have fun on the eye chart if you so desire. Of note, I am now up to revision 3 based on everyone's inputs and help




Carl Froehlich 01-04-2019 01:59 PM

A quick review yields some thoughts:
- #8 wire from the battery to the master solenoid, and then to the starter motor? These should be #2.
- While you went to great strides to document wiring details I note that you have several single point failure points in the power distribution.
- As I have posted on the past, a basic two battery - single alternator scheme provides more redundancy than a single battery, two alternaor scheme. The second alternator mitigates one risk only, the loss of the primary alternator.

Carl

mulde35d 01-04-2019 02:14 PM

Diagram
 
Good catch on the cable size. I have heard a lot of arguments on dual battery vs dual alternator and went with the dual alternator based on my plan to fly a lot of hard IFR. Battery is time limited while the backup alternator is indefinite. Can't get rid of all single point failures.

Question: How many amps does the typical starter pull?

mturnerb 01-04-2019 05:35 PM

Quote:

Originally Posted by Carl Froehlich (Post 1314081)
A quick review yields some thoughts:
- #8 wire from the battery to the master solenoid, and then to the starter motor? These should be #2.
- While you went to great strides to document wiring details I note that you have several single point failure points in the power distribution.
- As I have posted on the past, a basic two battery - single alternator scheme provides more redundancy than a single battery, two alternaor scheme. The second alternator mitigates one risk only, the loss of the primary alternator.

Carl

MY FWF kit included #2 for the cables you mention.

TFeeney 01-04-2019 06:24 PM

Jon, Iíd like to review the Visio file.
Iíve got the same system going on my -10, but my layout is like 20 pages. Gotta love the eye chart!

Sending PM with email.

Garmin connector kits arrive this weekend to start the harnesses.

control 01-05-2019 02:59 PM

Got it in my mail, thanx!
:D

Carl Froehlich 01-05-2019 04:04 PM

Quote:

Originally Posted by mulde35d (Post 1314084)
Good catch on the cable size. I have heard a lot of arguments on dual battery vs dual alternator and went with the dual alternator based on my plan to fly a lot of hard IFR. Battery is time limited while the backup alternator is indefinite. Can't get rid of all single point failures.

Question: How many amps does the typical starter pull?

Sorry - have to disagree. While you canít eliminate all single point failures you need not add to them.

PM me if you want to see another approach.

Carl

Walt 01-05-2019 06:06 PM

Quote:

Originally Posted by Carl Froehlich (Post 1314361)
Sorry - have to disagree. While you canít eliminate all single point failures you need not add to them.

PM me if you want to see another approach.

Carl

Carl, I believe your system adds quite a bit of complexity to help avoid the single point failure, in its place you've added many more failure points.

Just as an example, the link below is to a recent electrical power system failure on a Boeing 773, even with some of the brightest engineers designing the systems and all the redundant stuff it still can happen. The RAT and backup battery appeared to have saved the day.
http://avherald.com/h?article=4c1cc3f6

Personally I'm a fan of really simple electrical systems, single bat and 2 alternators is what I run, (I've never had to use the backup alt but nice to know its there if I need it).

mulde35d 01-05-2019 06:27 PM

Other Options
 
Carl, I would love to look over some other possible methods of wiring the primary power system. I do think others who read the forum would also appreciate the look though if you are able to post it to the forum in a similar manner. Luckily I, and many others, am early enough in the build phase that I could easily make changes to the system. So far I have had around 9 people ask for the visio product that I posted, which makes me believe we are really educating each other with this discussion.

As Walt mentioned, I am trying to keep it simple and relatively low cost (not that anything Garmin is low cost) while still having backups in place during IFR flight. I don't have much electrical engineering background and think many of us can benefit from at least seeing different ways of wiring the aircraft. Thanks for the input and I look forward to any drawings you may be able to post.

Ed_Wischmeyer 01-06-2019 06:23 PM

* You'll be spending a reasonable amount of time updating databases over the life of the plane. I wish my G3X system used the second power input on the display screens and GTN as a separate bus (on the ground) for programming, so I wouldn't have to pull a zillion circuit breakers to keep the battery draw down. And with a toggle switch, the second power inputs could be alternatively used for backup bus, whatever;
* The pin numbers for the serial buses, CANbus etc are overkill (I think that's what's in the diagram). Much more useful in the real world is a tabulation, not a diagram, of Serial Out 1 from XXX goes to Serial In 3 of YYY. It's easy enough to look at the pin numbers later on if you need them, but your approach makes it hard to see which port is which. This information is important because each of those serial ports has to be configured with the right protocol, baud rate, phase of the moon, etc.
* Yes, diagrams are cool, but for my money, tabulations of avionics interconnects are much easier to use. Your mileage may vary.
* When time comes to build, group your circuit breakers in a logical way so that you can find them easily in a hurry. Trim and autopilot especially.

Ed


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