dynon sensors

[bobnoffs]

hi all,
dynon fluid pressure sensors come with a black, green, and red wire. the wire is different from the tefzel wire i am used to. it seems to have an untinned center core and a tinned outer core with the strands fused together. question.........is there any reason i cannot trim this wire to a shorter wire?little bird on my shoulder is telling me to ask this question before i snip.
thanks

[lrgabriel]

I ended up replacing the connectors and contacts, and used aircraft wire all the way to them. Mostly to avoid splices, but also because I wasn't a fan of whatever wire Dynon used.

You should be able to shorten the pigtails with no problem. I do suggest you calibrate the sensors after you wire them, though--I found the stock cals to be slightly off.

[RV7A Flyer]

Are you talking about the Kavlico transducers?

If you are, and you changed the wires to tefzel, what pins/wire gauge did you end up using? I didn't much care for the large (and what looks like non-aviation) wires that came with them, but used as is...would be amenable to changing to tefzel...

Thanks...

[lrgabriel]

Kavlicos with Metri-Pack 150 series three position connectors (mine is probably a 2013-era four cylinder probe kit):

Connector assembly - Delphi 12110192
Tin-plated 20-22 AWG contact - Delphi 12089290
Gold-plated 20-22 AWG contact - Delphi 12191055
Gold-plated 18 AWG contact - Delphi 12191056
Crimper

I used 22 gauge wire (the sensor power draw is something like 2 mA).

Obviously, make sure the information above still applies to your model of sensor (I'm not sure what has and hasn't changed over time).

[Jesse]

I just splice the wires as necessary. Usually ground the black locally, splice the powers together and into the +V excite circuit then splice the greens each to the appropriate wire for the sensor being hooked up.

[scrollF4]

Not implying that you are overthinking it, but like the Saint said, I'd splice and press on. 200+ hours on mine, no problem so far.

[lrgabriel]

To each their own...but industry standard is to avoid splices, especially in areas of high vibration (like the engine compartment of a piston single).

I'm admittedly a bit passionate about wiring, but I've seen a lot of hokey experimental garbage fail in intermittent and interesting ways. No matter how inconsequential a fluid pressure sensor may be to safety of flight, splicing in a foot section of unknown (most likely automotive) wire wasn't acceptable to me...especially forward of the firewall.

[RV7A Flyer]

Originally Posted by lrgabriel

To each their own...but industry standard is to avoid splices, especially in areas of high vibration (like the engine compartment of a piston single).

I'm admittedly a bit passionate about wiring, but I've seen a lot of hokey experimental garbage fail in intermittent and interesting ways. No matter how inconsequential a fluid pressure sensor may be to safety of flight, splicing in a foot section of unknown (most likely automotive) wire wasn't acceptable to me...especially forward of the firewall.

My thoughts exactly, which is why I'd like to re-pin the connector to avoid the splice and use proper wire (of the proper gauge). As it is, I have to go from the smaller gauge wires from the Skyview EMS to the larger gauge on the sensor, and it just makes for a messy installation with more possible failure points.

There's right, and then there's not right...

[RV7A Flyer]

Originally Posted by Jesse

I just splice the wires as necessary. Usually ground the black locally, splice the powers together and into the +V excite circuit then splice the greens each to the appropriate wire for the sensor being hooked up.

May not apply to your system, but the Dynon wiring instructions say to use the ground from the EMS module, not local ground. Might not make any difference (especially if you have different display), but for those installing Dynon equipment, as always, check the manual...

[Jesse]

Originally Posted by RV7A Flyer

May not apply to your system, but the Dynon wiring instructions say to use the ground from the EMS module, not local ground. Might not make any difference (especially if you have different display), but for those installing Dynon equipment, as always, check the manual...

For most using a forest of tabs on the firewall for ground, a local ground for the sensors is on the firewall, close to the forest of tabs. The Dynon grounds act as courtesy grounds when/where needed. Of course, you could use those as well.

As for splices versus new connector, you obviously need to make sure you know how to assemble the connector, have a pin appropriate to the wire size used (22AWG) and have a crimping no tool that will get as good of a crimp as the professionally/production crimped originals. With those 3 issues in play, my personal opinion is still better to splice with connectors and crimp tools that we are already using throughout the build. Also, I'm talking if crimp splices, not solder splices in the engine compartment. Choose the way that makes you most comfortable. None of these ways are wrong.