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G3X touch wiring

propflipper

Active Member
Hopefully the G3X expert can chime in on this :

I have seen these beautifully constructed Garmin connectors, done by professionals, with shield terminations exiting solder sleves and neatly looping back to the connector in color coded green wire. They look great, and I am sure they probably work great. But according to the G3X installation manual two wiring crimes have been committed.

On page 24-10 of the G3X touch installation manual it states that " the flat braid should go out the front of the termination toward the connector. It is not permitted to exit the rear of the termination and loop back to the connector."

In a note at the bottom of 24-10 it states" Flat braid as opposed to insulated wire is specified in order to allow continuing air worthiness by allowing for visual inspection of the conductor"

Also, why not just strip about 4" of insulation off, pull the wires though the shield , crimp a lug on it and call it good ?


I would sure hate to hear the inspector tell me to redo the harness.

As always thank you for your feed back.

Tom
 
Hopefully the G3X expert can chime in on this :

I have seen these beautifully constructed Garmin connectors, done by professionals, with shield terminations exiting solder sleves and neatly looping back to the connector in color coded green wire. They look great, and I am sure they probably work great. But according to the G3X installation manual two wiring crimes have been committed.

On page 24-10 of the G3X touch installation manual it states that " the flat braid should go out the front of the termination toward the connector. It is not permitted to exit the rear of the termination and loop back to the connector."

In a note at the bottom of 24-10 it states" Flat braid as opposed to insulated wire is specified in order to allow continuing air worthiness by allowing for visual inspection of the conductor"

Also, why not just strip about 4" of insulation off, pull the wires though the shield , crimp a lug on it and call it good ?


I would sure hate to hear the inspector tell me to redo the harness.

As always thank you for your feed back.

Tom
There are an awful lot of planes flying with the solder sleeves you mention. They are not failing in earth shattering numbers, planes falling out of the sky fashion. Oh, another thing, I cannot imagine any inspector I have ever worked with decide to climb upside down underneath the panel to closely examine the connections to an instrument. if you have an inspector use a solder sleeve as a reason for not giving an airworthiness certificate, well. . . reread the previous sentence. Don’t expect that to happen!
 
Opinion

My opinion is that is written because they probably think mechanics need more instructions. I am an engineer, I can decide which is best. And I will show you the math why.

“Badges we dont need no stinking badges”

On a serious note, i try and avoid using uninsulated copper, and avoid copper braid because it has a habit of shedding copper strand. Not good around connectors and harnesses. In my day job, that design would get rejected. The industry standard allows copper strands to be broken in braid. A short insulated copper wire is preferred even thou it has slightly higher inductance. And yes I am being a nit pick, just my preference.
 
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Shield Termination

Hopefully the G3X expert can chime in on this :

I have seen these beautifully constructed Garmin connectors, done by professionals, with shield terminations exiting solder sleves and neatly looping back to the connector in color coded green wire. They look great, and I am sure they probably work great. But according to the G3X installation manual two wiring crimes have been committed.

On page 24-10 of the G3X touch installation manual it states that " the flat braid should go out the front of the termination toward the connector. It is not permitted to exit the rear of the termination and loop back to the connector."

In a note at the bottom of 24-10 it states" Flat braid as opposed to insulated wire is specified in order to allow continuing air worthiness by allowing for visual inspection of the conductor"

Also, why not just strip about 4" of insulation off, pull the wires though the shield , crimp a lug on it and call it good ?


I would sure hate to hear the inspector tell me to redo the harness.

As always thank you for your feed back.

Tom

Good Morning,

This is our recommendation for the buildout of the connectors, keeping the shield termination as short as possible, and lessening the likelihood of mechanical issues that could be induced with looping the braid backwards towards the connector.

The note below this section provides a reference to FAA AC 43.13-1B Chapter 11, Section 8 (Wiring Installation Inspection Requirements). You can find a lot of very helpful information on the subject there as well.

Let us know if you have any other questions.

Thanks,

Justin
 
On page 24-10 of the G3X touch installation manual it states that " the flat braid should go out the front of the termination toward the connector. It is not permitted to exit the rear of the termination and loop back to the connector."

In a note at the bottom of 24-10 it states" Flat braid as opposed to insulated wire is specified in order to allow continuing air worthiness by allowing for visual inspection of the conductor"


Which version of the G3X Touch installation manual are you using? I see this language in Section 25, page 6, in revision AP of the G3X Touch installation manual (190-01115-01 Revision AP), but it appears to contradict the guidance in the GTN installation manual that Richard posted above. For reference, I have GTN 6xx/7xx installation manual 190-01007-A3, Revision 4. The diagram Richard noted is located on Page 3-18 of that manual.

Is there a good reason that Garmin appears to offer different advice in different equipment installation manuals? Or am I misunderstanding?
 
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When building my shield drains, I relied heavily on Garmin's "Wiring Fundamentals Series" YouTube videos. In this series, the tech clearly runs the shield drain wire backwards and then loops it forward toward the connector.

Solder Sleeve Method

Solder Method

If I’m not mistaken these videos are out of date in that they recommend now to fold the braid back over the jacket before using the solder sleeve or solder to install the drain wire. Something to do with less likely the heat will damage the insulation on the wires.
http://www.steinair.com/wp-content/uploads/2016/03/RAYCHEM-SOLDER-SLEEVE-INSTRUCTIONS.pdf

http://www.steinair.com/wp-content/...thiness-Bulletin-AWB02-009-SOLDER-SLEEVES.pdf

http://www.steinair.com/wp-content/uploads/2016/03/Military-Solder-Sleeve-Installation-practices.pdf

http://www.steinair.com/wp-content/...rcular-AC-021c99-AIRCRAFT-WIRING-BONDING-.pdf
 
It would seem to me that leaving all those shields braided it would get awfully crowded really fast, the audio panel would be way worse than these...

Steve, don't make me redo all this :p

2022050417374868--1463188037751555226-IMG_1788-X2.jpg
 
When building my shield drains, I relied heavily on Garmin's "Wiring Fundamentals Series" YouTube videos. In this series, the tech clearly runs the shield drain wire backwards and then loops it forward toward the connector.


As someone else mentioned these videos are out of date. I contacted a G3Xpert over email. Michael was his name. He was surprised the videos existed and said they would take them down. The correct method is in the latest edition of the g3x install manual.
 
I was told by a very reputable shop that most of you have probably heard of that this is the old way of doing it and professional avionics shops no longer follow this method.
Christopher,

Professional avionics shops would much rather invest in tools and materials than additional labor, so that explains why they probably all use solder sleeves.

That doesn't mean that the "old way of doing it" is bad or even inferior.

Steve
 
There are instances where there is more than one shield drain wire used at the same shield termination. Such as when daisy chaining shields between adjacent wires. So on a drain that bonds to a back shell I could see orienting it towards the connector. Straight line. But a second shield drain wire going to an adjacent shielded cable should probably head in the opposite direction (legacy direction), away from the connection under each solder sleeve on both of those wire assemblies. Nothing wrong with a nice sweeping loop as long as some Gomer doesn’t honker down on the bundle causing the nice radius to collapse into a hard return bend. I have seen such problematical tight bends on radio antenna coax (ultimate shielded wire) installs where Gomer folds excess cable back forth hard bending the radiuses like they are single stranded wire. This will do horrific things to the coax. I think Garmin got tired of having to answer Gomer on the help line with issues such as this and hauled off and updated the instructions to used braiding and avoid bends. Same thing happened with CAN nodes. Originally Garmin’s instructions were to only ground the CAN bus cable shield at each end of the bus (termination LRUs) and to just daisy chain the shielding at the intermediate nodes. But again there was enough shoddy workmanship causing CAN errors they turned around and shot gunned it by specifying bonding the CAN bus shielding to LRU backshells at all node locations. The early installs that were done correctly are still reliable and going strong. But there is always some Gomer out there and Garmin has to design their instructions to take into account this lowest denominator.
 
As someone else mentioned these videos are out of date. I contacted a G3Xpert over email. Michael was his name. He was surprised the videos existed and said they would take them down. The correct method is in the latest edition of the g3x install manual.

Huh.. They were newly released when I did my wiring a few years ago so who knows. Didn't realize things change so quickly in aviation :) Well, if I ever add more avionics goodies, I'll have a new way to do the connectors, but I will not be going back in and re-doing 50 shield drains, thankyouverymuch.
 
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