Running Wires Together

[aitor11]

Hi!

I'm slowly wiring my RV-9A and the time to start running wires for my Dynon system is here. I have a couple questions that can really help to get things sorted out.

1. Can I run my A/P harness together with the COM Antennas coax cables? Better to run them with the SkyView Network coming from my ADAHRS?
2. Since I will have my ADAHRS in the back close to where I'm planning to install my GPS2020 Receiver, can I run wires for both together?
3. Can the Transponder harness run next to either the A/P, SkyView for ADAHRS and/or the GPS2020? (I'll install my transponder in the back to keep the antena as close as possible from the box)

So far I've been able to keep what I call regular power cables (NAV, Strobes, Landing, TAXI Lights, etc) separated from the avionics, but I'm running out of space to run wires.

Thanks in advance!

Aitor

 

[G-RVMS]

I’m finishing up my wiring (it’s taking ages to tidy it all up).

1. Your Coaxial cables are screened (double screened in the case of RG400), so should be fine.
2. I have the ADAHRS and GPS close to each other and have no noise or interference.
3. I haven’t experienced any interference with any of these. I have Flyleds lights and strobes and have no interference with those either.

You‘re more likely to be limited by the size of cable holes rather than interference from the Dynon kit (assuming you earth any shields as recommended), as the RG400 Coax can use up space quickly, as can the D9 network cables.

good luck

 

[Raymo]

You can safely run all the wires together. My XPNDR antenna is on the right, in front of the spar, and protected by the gear weldment. Same on the left for my ADS-B-IN antenna. Comm antenna runs down the right with the XPNDR and wing wires while left wing pitot heat runs with the wires on that side. I twisted the pos/neg pitot wires with a drill motor to help reduce magnetic interference.

Due to limited space in the spar pass-throughs, my AD-AHRS cable, flap, fuel pump, trim and A/P wiring use the center section spar pass-throughs. AD-AHRS are mounted on two 1"x1" extruded aluminum angle at first bulkhead behind the baggage compartment.

 

[aitor11]

Thank you both for taking the time to reply. I'll move forward now!

Aitor

 

[DBRV10]

There is one set of wires I would keep segregated. I have had to diagnose and solve this on a clients plane, so I would follow this carefully.

The SV-GPS 4 twisted wires, should not be run alongside coax (even RG400) that is used for a certified GPS, a VHF comm and probably VHF NAV for any significant distance. I do not have a maximum length recommendation but the case I found had GPS wires and coax run in the same bundle over about 8-9 feet.

The noise generated on the VHF comm was not able to be defeated. So as a precaution keep them well away from those items.

 

[aitor11]

Thank you for the reply. I have not run the SV-GPS yet, but was planning on doing so on the same side I have the network cable. All cables get together between the spar and the firewall (probably 3 or 4 feet) I’ll take a look and see what I can move.

Aitor

There is one set of wires I would keep segregated. I have had to diagnose and solve this on a clients plane, so I would follow this carefully.

The SV-GPS 4 twisted wires, should not be run alongside coax (even RG400) that is used for a certified GPS, a VHF comm and probably VHF NAV for any significant distance. I do not have a maximum length recommendation but the case I found had GPS wires and coax run in the same bundle over about 8-9 feet.

The noise generated on the VHF comm was not able to be defeated. So as a precaution keep them well away from those items.

 

[DBRV10]

The network cable will be fine. Maybe 3-4' will be fine too.

Just keep it to a minimum.

 

[airguy]

Any powered transmitter coax, such as comm and transponder, are going to give problems in proximity to other wire bundles, even with good high-quality coax.

 

[RVDan]

General design guidance it to keep coax cables for transmitters and receivers separated as much as practical. even double screening does not limit 100% of the signal. A separation of 2-3 inches is desirable. If you have to follow the same path as other cables, stand the coax off of the other wire bundle. This is cheap insurance that you won’t be chasing down EMI/RFI issues when you are done.