Van's Air Force
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Another Heated Pitot Wiring Question
- Thread starter azflyer21
- Start date
I put all the wires for the pitot tube in wing just in case (with enough wire to reach cabin). (14 Ga) IIRC, one power wire supplies controller which in turn supplies the pitot tube itself.
In talking with Steinair folks during my panel build it turns out the harness has a power supply for pitot in one of the molex connectors but not a ground - so I'll run my ground wire to the grounding block but use the molex supply for my hot.
Since you have Dynon may be different (I'm using Garmin) but I'm sure if you give the guys at Steinair a call (Josh is the RV14 guru) they will give you the information you need.
In talking with Steinair folks during my panel build it turns out the harness has a power supply for pitot in one of the molex connectors but not a ground - so I'll run my ground wire to the grounding block but use the molex supply for my hot.
Since you have Dynon may be different (I'm using Garmin) but I'm sure if you give the guys at Steinair a call (Josh is the RV14 guru) they will give you the information you need.
Can you not just ground the black to the wing? Do you have to go All the way to your grounding block?
You never "have to" take a ground all the way to the grounding block. The reason for taking grounds to the grounding block is to avoid ground loops which can cause noise in audio circuits. Bringing as many grounds as possible to a single point (establishing a uniform ground potential) avoids this risk. Grounds that carry more current through structure back to the reference ground (negative battery terminal attachment point to airframe) have the potential to produce more noise, since more current has more energy to induce noise.
Richard Connell
Well Known Member
Everyone should really read the whole Aeroelectric books and site.
The forum is good for specific questions. Last I looked bob was still active.
No problem grounding the pitot heat locally.
georgemohr
Well Known Member
I clicked on this for a heated discussion 
Halleffect
Active Member
The Van's fuselage harness (built and sold by SteinAir) has a 14AWG pitot heat wire to the wing root. The Van's wing harness does not include pitot heat. I added 14AWG twisted pair and ran the ground to the wing root grounding point on the fuselage. I used the 22AWG wire in the wing and fuselage harness originally for the stall warning switch for the pitot heat controller status (assuming the Dynon controller has status wire like the Garmin).
dmattmul
Well Known Member
Plans built 14 (mine) has the pitot tube heat running right by the magnetometer (what could go wrong) so decided to use 14 awg. shielded twisted pair back to the tree of grounds on the firewall after reading about multiple failed magnetometer interference testing on the 14. Tried moving the cable as far aways from the magnetometer as possible. Still no joy. The good news is zero noise in my headset but still fails the magnetometer interference test. I have 2 AHRS and G5 and do not get a mis-compare but still not satisfied.
The shield is useless at magnetic shielding, but the twisted pair should help. Make certain there’s no way for the return current to get back (like thru the wing skin) except the return wire.
Richard Connell
Well Known Member
I’d just relocate the magnetometer to the opposite wingtip. A bit of a pain in the butt but probably only a few hours work at worst.
