Wire sizes

On Jul 29, 9:50*am, Bob Kuykendall wrote:
On Jul 27, 5:29*am, "01-- Zero One" wrote:

For power especially, use ONLY Tefzel wire!

Here we are again. Is Tefzel the best stuff to use these days? Yeah,
pretty much, no disagreement there. Is it important to use good
materials? Yup, pretty important.

Is it the only stuff to use, the stuff that you must use? All-caps and
exclamation point aside, it depends. I have only a couple of always/
never rules about aircraft wiring, and they're about fuses, not
Tefzel.

Comparatively speaking, I happen to think that how you wire things is
more important than what you wire them with. Given the choice between
organized bundles, well supported, appropriately fused, protected from
abrasion, and kept away from moving parts, all executed in Electron
Hut automotive wire, versus a rats nest of unmarked white Tefzel going
every which way, I'll take my chances with the Electron Hut system.
But, that's just me.

I've written that all before. But here's some new information content:
Be careful about drilling holes around wiring bundles, especially
where you're drilling metal. In one of my current projects, we've
found chips of aluminum swarf embedded in the Tefzel insulation of
wires pretty deep within wiring bundles. We undertook a program to
unwrap every accessible wiring bundle and clean out the chips, and now
are taking special precautions to keep chips out in the first place.
It's certainly a thing to think on.

Thanks, Bob K.

Bob, I actually agree, and while harping on components/tools it is
what you do with them that matters. A good wiring job should just
really look neat and tidy and organized. A look at the guts of a Duo-
X had me impressed at factory wiring (for a change). Amongst the
articles at http://www.aeroelectric.com/articles.html are some
related good discussions on proper workmanship and fuses/breakers etc.
And why several glider manufacturers use no color coding or labeling
or seem happy to put out a rats nest of wiring is beyond me. Part of
my grumpiness about this stuff is having experienced wiring relate
problems, including electrical shorts etc.

Darryl

On Jul 28, 9:10*pm, ContestID67 wrote:
Couldn't agree more on the use of tefzel. It is an FAA requirement.

Would you please tell me what regulation specifes the use of Tefzel
wiring in gliders.

I'm particularly interested since my nearly new glider came from the
factory with wiring that appears to be PVC insulated. Although my
serial number is Experimental the model now has an FAA standard
airworthiness certificate.

thanks

Andy

On Jul 29, 1:00*pm, Andy wrote:
On Jul 28, 9:10*pm, ContestID67 wrote:

Couldn't agree more on the use of tefzel. *It is an FAA requirement.

Would you please tell me what regulation specifes the use of Tefzel
wiring in gliders...

Color me confuseled as well. I've designed sailplane control systems
to the dictates of 14 CFR part 23 (and JAR 22, they're quite similar),
and I often use AC43.13 as a guideline, so I'm pretty familiar with
those FAA resources. But I can't find any material in either that
dictates the use of Tefzel or its generic ETFE.

Furthermore, those of us operating Experimental, Amateur-built
aircraft are not bound by the dictates of either part 23 or AC43.13.
Those of us operating Experimental, Exhibition or Experimental, Racing
may or may not be so bound, depending on the specific language of the
operating limitations document that must accompany the special
airworthiness certificate.

Thanks, Bob K.

Bob, we don't really disagree about much of anything in this discussion.

However, this is not an Advisory Circular. It is a discussion on
"usenet" where opinions are like buttholes... everybody has one. That
is why when I say "For power especially, use ONLY Tefzel" I am hoping
that if folks do not pickup on anything else said in this exchange, they
will remember that. It is the same reason that I say emphatically
"ABSOLUTELY mount a 3-5 amp fuse on each battery!!!!!"

As you have surely found in your considerable experience, glider wiring
as a whole is abysmal! If the plane is more than a couple of years old,
there is going to be some sort of rube goldberg, thrown together battery
connection, or what-have-you. So if they have a rats nest but somehow
replaced the zipcord and speaker wire with Tefzel along the way, they
will at least not be filling up the cockpit instantaneously with acrid,
harmful smoke when the accidental short happens under the seatpan. And
if they heard my second point and actually put a fuse on the battery,
they will do nothing but blow the fuse and not roast their rump.

So, while I agree that if they used all the best aviation wiring
practices that you mention below about organization, strain relief,
abrasion free, etc. but chose to use Radio shack wire, they would most
likely never have a problem. But that, from my experience, is never
going to happen. Some of the brightest pilots I know somehow believe
that when it comes to wiring, just throwing something together will
suffice.

Regards,

Larry



"Bob Kuykendall" wrote in message
:

On Jul 27, 5:29 am, "01-- Zero One" wrote:

For power especially, use ONLY Tefzel wire!

Here we are again. Is Tefzel the best stuff to use these days? Yeah,
pretty much, no disagreement there. Is it important to use good
materials? Yup, pretty important.

Is it the only stuff to use, the stuff that you must use? All-caps and
exclamation point aside, it depends. I have only a couple of always/
never rules about aircraft wiring, and they're about fuses, not
Tefzel.

Comparatively speaking, I happen to think that how you wire things is
more important than what you wire them with. Given the choice between
organized bundles, well supported, appropriately fused, protected from
abrasion, and kept away from moving parts, all executed in Electron
Hut automotive wire, versus a rats nest of unmarked white Tefzel going
every which way, I'll take my chances with the Electron Hut system.
But, that's just me.

I've written that all before. But here's some new information content:
Be careful about drilling holes around wiring bundles, especially
where you're drilling metal. In one of my current projects, we've
found chips of aluminum swarf embedded in the Tefzel insulation of
wires pretty deep within wiring bundles. We undertook a program to
unwrap every accessible wiring bundle and clean out the chips, and now
are taking special precautions to keep chips out in the first place.
It's certainly a thing to think on.

Thanks, Bob K.

On Jul 28, 9:10*pm, ContestID67 wrote:

Couldn't agree more on the use of tefzel. *It is an FAA requirement.


On Jul 30, 6:18 am, Bob Kuykendall wrote:

Would you please tell me what regulation specifes the use of Tefzel wiring in gliders...


Valid comment. I shouldn't be so blith with my use of the "FAA" word.

Let me rephrase. Every book I have ever read about aviation wiring,
and every aviation tech I have ever worked with, and every A&P who has
every looked over my shoulder and signed my log book, has always
required Tefzel (ETFE).

Now, if that isn't an implicite FAA requirement, I don't know what
is. However, there must be something in the regs that is driving all
this. While there probably isn't a reg that says "you must use ETFE",
is there one that says something about wiring being; Abrasion
resistant? Burn resistant? Doesn't release toxins? Doesn't fray?
If there isn't an FAA reg on this, I can start going back to Radio
Shack. ;-) Only kidding...really.

However, when I council a newbie about why his wiring is just plain
wrong, why he shouldn't use spade lugs, and why fuses at batteries (!)
are a necessary thing, etc, etc, I often blithly spead the "FAA" word
around to put the fear of God in them. I will probably continue that
habit. And I don't care if it is standard certified or experimental,
my (high) standards are all the same. It keeps life simpler that way.

My $0.02.

- John DeRosa

On Jul 30, 4:31*am, ContestID67 wrote:
However, when I council a newbie about why his wiring is just plain
wrong, why he shouldn't use spade lugs, and why fuses at batteries (!)
are a necessary thing, etc, etc, I often blithly spead the "FAA" word
around to put the fear of God in them. I will probably continue that
habit. *And I don't care if it is standard certified or experimental,
my (high) standards are all the same. *It keeps life simpler that way.

Thanks for your well-reasoned approach. We definitely agree on the
major points he It's important to think things out before you do
them, to do quality work, and to use good materials.

But I'm still concerned that saying something is an "FAA requirement"
when it's really not sets a bad precedent. As we've see with the 337
process, when you say something like that too often, pretty soon even
the FAA believes it, and then they start to demand it even in cases
where it's downright silly. The next thing you know, you get ramp-
checked and then lose a day at the Nationals because the 24ga wire to
the 9-volt battery of your gear warning system, a wire carrying at
most a few milliamps, isn't FAA-PMA stamped Tefzel(tm) brand wire. And
don't laugh, sillier things have happened.

Thanks again, Bob K.

On Jul 30, 4:31*am, ContestID67 wrote:

However, when I council a newbie about why his wiring is just plain
wrong, why he shouldn't use spade lugs..

Ok, now I'm curious again. What sort of battery do you use to power
your glider systems and what sort of terminals does it have?

thanks

Andy

I dont think he's referring to batteries with this phrase. He's
probably talking about not using spade lugs on terminal blocks (where
ring connectors should be used). All of the small VRLA batteries that
I've seen in sailplanes have Faston connectors, so Faston "spade lugs"
would have to be used there.

-John

On Jul 31, 10:15 am, Andy wrote:
On Jul 30, 4:31 am, ContestID67 wrote:

However, when I council a newbie about why his wiring is just plain

wrong, why he shouldn't use spade lugs..

Ok, now I'm curious again. What sort of battery do you use to power
your glider systems and what sort of terminals does it have?

thanks

Andy

On Jul 31, 7:15*am, Andy wrote:
On Jul 30, 4:31*am, ContestID67 wrote:

However, when I council a newbie about why his wiring is just plain

wrong, why he shouldn't use spade lugs..

Ok, now I'm curious again. *What sort of battery do you use to power
your glider systems and what sort of terminals does it have?

thanks

Andy

Faston = blade connector (typically used in 1/4 wide blades for glider
applications) is not a spade connector. AGM batteries will typically
have a Faston style connector or larger ones will have a screw binding
post (like the batteries on my ASH-26E - which gets crimp on ring
connectors not a spade connector to connect to the batteries) . Faston
blade connectors (use nylon fully insulated where possible) are very
suitable for use in aircraft, see again my favorite source
http://www.aeroelectric.com/articles/faston3.pdf

Crimp on ring connectors should be used on binding posts instead of
spade connectors which can simply fall out easily. However like the
article above advocates a Faston style binding block is even easier to
use, and is tool free. Properly done the Faston style binding blocks
will not come undone. Many things like fuse holders and switches also
are available with Faston blade connections, if nothing else they are
a good idea since you do not need to get a screwdriver down inside
some hard to reach place and/or risk dropping a screw into the guts of
your glider.

Schleicher uses Faston style binding blocks in their gliders. Cobra
uses them in their trailers, ...

Darryl

On Jul 31, 8:35*am, Darryl Ramm wrote:

Spade ... blade....

I thought they were the same thing so obviously I don't speak American
very well yet. When I look up spade connector it looks more like a
fork to me. In fact fork lug is also, perhaps more commonly, used to
describe this terminal type. Agree they are not the best choice but
they do make life a lot easier if one terminal has to be removed from
a stack.


Andy