Beginner Wiring Question

[ZK-SVH]

Hi Everyone.

I‘m building/assembling an ICP Savannah down in New Zealand, similar I guess to a Zenith 750 STOL, installing a Dynon Skyview system with autopilot. Luckily I’m getting a fair bit of help in this area because I know next to nothing about wiring and avionics.

I‘m installing the following electrical /avionic stuff from the rear fuselage forward in basically two bundles, port and starboard.
network cable x 1, strobe , nav and landing lights (all LED), elevator trim servo wire, com antenna cable, transponder antenna cable, GPS wires, headset jack wires, positive and negative 12volt cables from battery, PTT, and lastly autopilot servo power, ground and switching.

My very basic questions are given I can pretty much put anything up either side (but it will be easier to keep the bundles similar size, is there anything in this mix that I‘d ideally want not to bundle together and which of this stuff should be installed using shielded wiring.

Thanks

Peter

 

[Rhino]

It's not always possible to separate wiring the way you'd like. But as a general rule, you should keep all RF, servo and high power cables away from your audio and data wires. Use shielded wiring, preferably balanced, for all audio and data lines. Where these different types of wires cross, try to have them do it at right angles as opposed to parallel. Though using LEDs, it wouldn't hurt to keep the lighting wires away from audio and data as well, though that isn't a hard and fast rule. Most important is to use a common ground point for all your audio/data wiring, along with a common ground point for all your power wiring. Ideally, those two should be the same common ground point. You'll find more on this in the Avionics sub-forum. You didn't mention ADAHRS, but that's another story all by itself. There's an entire section on that in the manual, and you'll find other stuff on it in the forums here.

 

[ZK-SVH]

It's not always possible to separate wiring the way you'd like. But as a general rule, you should keep all RF, servo and high power cables away from your audio and data wires. Use shielded wiring, preferably balanced, for all audio and data lines. Where these different types of wires cross, try to have them do it at right angles as opposed to parallel. Though using LEDs, it wouldn't hurt to keep the lighting wires away from audio and data as well, though that isn't a hard and fast rule. Most important is to use a common ground point for all your audio/data wiring, along with a common ground point for all your power wiring. Ideally, those two should be the same common ground point. You'll find more on this in the Avionics sub-forum. You didn't mention ADAHRS, but that's another story all by itself. There's an entire section on that in the manual, and you'll find other stuff on it in the forums here.

Hey thanks so much, I’m sure we’ll have more questions as we get into it.

FWIW when I narrowed the avionics choice down to Dynon/Garmin/MGL this forum and Dynon’s involvement in it was a big factor in going with Dynon.

Peter

 

[Rhino]

No problem. Wiring help is a common topic here. And I need to correct myself. There is no avionics sub-forum here. The whole place is an avionics forum. I was thinking of a different site. Sorry.

 

[BobD]

I'm no expert, but my recent AP Servos installation gave me lots of lost connection problems until I moved the transponder and radio coax leads well away from the Servo cabling.

 

[Rhino]

I try to keep RF cables as isolated from everything else as possible, and use high quality cables (RG-400 or better). Too many homebuilders use cheap coax for RF, and have problems as a result. Since Dynon servos operate on a PWM signal, you could easily make the argument that they're data cables, and should be shielded/separated accordingly.

 

[GalinHdz]

FWIW, I ran all my RF cables (Coax) along one side of the fuselage while the low voltage wires (Signals) along the other side. The other thing you should be vigilant is to make sure all ground connections are correct. I have a fiberglass airplane (KIS-4) so proper grounding is even more critical than on spam cans.