Installing a Dynon Heated (Regulated) in a flying RV-10

[mikelupo]

Hello!
I am in the planning phase of installing a complete Dynon system to replace my antiquated TruTrak EFIS. One of the things I opted for was the heated Pitot with AOA.

Please allow me a moment to form the context of an electrical question regarding the grounding.

Page 3-2 of the referenced installation documentation [1] states:
Do not connect the Black (Ground) wire to the airframe as a Ground connection.Doing so will introduce high currents (10A) into the airframe. This can introduce asignificant voltage drop, and potentially cause engine instrumentation, avionics,and audio system electrical problems

A few pages later (3-4) Figure 7 shows the ground terminating on the aircraft ground.

My question:
Are they saying that I should home-run the ground wire all the way back to my common ground block behind my panel? If not, then please advise.
FWIW: The current heated Pitot is grounded on the airframe to a wing rib.

[1] https://dynonavionics.com/includes/...AOA_Pitoti_Probe_Installation_Guide_Rev_G.pdf

Thank you in advance!
Mike

 

[airguy]

Yes, ideally you would run a home-run ground through the wing to a common grounding block, to limit any resistance and subsequent voltage drop in the circuit.

 

[Mich48041]

Grounding the pitot heat locally is unlikely to cause any problems in a RV-10,
Dynon does not know what kind of airplane their pitot tube will be installed in.
So their instructions are extra cautious. You could call Dynon or Stein Air or Vans.

 

[BobTurner]

I’m with the ‘local grounding is probably okay’ camp. The controller will command the power needed, so a small loss in the airframe is only important in a ‘max heat needed’ situation. Since it’s a dc current, you should not see any problems on audio circuits, etc. BUT a 10 amp current can generate a considerable magnetic field. The power wire must be far from any magnetometers. If that is not possible, then do not ground locally (insulate if necessary.) Instead twist the ground return wire with the power wire, and do not ground the ground until well past the magnetometer.

 

[olyolson]

Mike,

I have a an RV-8 with the Dynon heated AOA/Pitot probe and I grounded it it locally in the wing. I have my magnetometer in the fuselage behind the aft baggage compartment on the centerline of the fuselage. I have never had any issues

 

[mikelupo]

Thank you everyone for your replies! I won't be near a magnetometer so I don't think that grounding it locally will be an issue. I may still route back to a grounding block anyway, but it's nice to know that I have options.

 

[lr172]

both of my planes utilize extensive frame grounding, including the pitot heat, lights, autopilots, etc. Never had an issue. Frame grounding is NOT inherently bad, but can expose other electrical flaws or short cuts used. Dedicated grounds are often used for sensitive components that are susceptible to problems from noise or ground loops.

Larry