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-   -   GTP59 Shield Wire (https://vansairforce.net/community/showthread.php?t=179184)

TASEsq 01-31-2020 09:46 PM

GTP59 Shield Wire
 
Planning my wing wiring and notice that the G3X manual on page 21-3 calls for the sheild of the GTP59 wire to be attached to a 16 AWG wire and then the backshell.

I would like to split this cable at the wing root with a CPC connector - but the 16AWG wire will mean it needs to go into large pin connector.

I notice the power wire to the temp probe is not anywhere near this big - does anyone know why i cant use a 22AWG wire for this shield pass through the connector (and at the dsub end to the AHARS)?

fl-mike 02-01-2020 07:59 AM

That has to be a misprint. There is no electrical reason for a 16 AWG wire for the shield drain wire. That?s pitot heat size! 22 AWG would be fine.

PilotjohnS 02-01-2020 08:35 AM

My harness
 
I had my wing harness built by a top shop who advertises on here and they did not use 16awg; they used something smaller. If I had to guess, it would be 22awg

bjdecker 02-01-2020 08:36 AM

Weird...but..
 
I agree - this is a shield wire, not a DC return or common.

However, instead of a single 16AWG to carry the shield - use two 20AWG (or 22AWG) wires in your connector.

Just a thought.


Cheers!

Walt 02-01-2020 09:02 AM

Best not run it through a connector at all, the shield on the GTP is a heavy double shield probably for good reason.

rocketman1988 02-01-2020 10:45 AM

And...
 
And it is a factory cable.

According to the avionics shop, lots of people cut/extend/shorten this cable...

TASEsq 02-01-2020 12:38 PM

Quote:

Originally Posted by Walt (Post 1404750)
Best not run it through a connector at all, the shield on the GTP is a heavy double shield probably for good reason.

The other reason for this question, is i was thinking of putting the probe in the left wing - where the pitot tube hole will be in the skin. I wanted to be able to run the cables in the wing now, to save fishing it through the wing later. I was figuring a connector at the probe would be a good idea anyway in case the probe ever needed to be removed?

In the install manual they talk about extending the cable up to 25ft is fine, and it calls for “three wire twisted shielded cable” - but unfortunately doesn’t recommend a gauge.

The gtp59 isn’t listed in the current draw table on page 2-14 but I would imagine it doesn’t draw anything. I was thinking a 22awg would have been fine? https://www.steinair.com/product/22-...ctor-shielded/

Here’s one from a citrus g1000 install - looks like 20 or 22 awg maybe in that little connector?

PilotjohnS 02-01-2020 02:32 PM

Quote:

Originally Posted by TASEsq (Post 1404784)
The other reason for this question, is i was thinking of putting the probe in the left wing - where the pitot tube hole will be in the skin. I wanted to be able to run the cables in the wing now, to save fishing it through the wing later. I was figuring a connector at the probe would be a good idea anyway in case the probe ever needed to be removed?

In the install manual they talk about extending the cable up to 25ft is fine, and it calls for ?three wire twisted shielded cable? - but unfortunately doesn?t recommend a gauge.

The gtp59 isn?t listed in the current draw table on page 2-14 but I would imagine it doesn?t draw anything. I was thinking a 22awg would have been fine? https://www.steinair.com/product/22-...ctor-shielded/

Here?s one from a citrus g1000 install - looks like 20 or 22 awg maybe in that little connector?

When I read the Garmin G3x install manual this morning, I thought it said that all wires are 22awg unless otherwise noted. JMHO YMMV

TASEsq 02-02-2020 12:42 PM

Does anyone know if Garmin has a support email where you can ask these kinds of questions?

bjdecker 02-02-2020 02:59 PM

email to:

g3xpert@garmin.com


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