Wiring a Sailplane

Well got everything plumbed the other day and need
to wire the entire electrical system...not a whole
lot to do really

New 12v 9.0 amp battery
5 and 3 amp Klixon Breakers for the Tasman and the
Microair 760
Aux. Power source Car Cig type plug-in
Bus Bar
Master Switch
PTT Switch
Microphone and speaker
In-line fuses

Anyone out there got any sage advice? Drawings of simple
wiring diagrams they can email me or links to sites?

Wiring, Seals, W&B, Annual and FLY...

Thanks...

Beach

On Dec 11, 5:35 am, Travis Beach
wrote:
Well got everything plumbed the other day and need
to wire the entire electrical system...not a whole
lot to do really

New 12v 9.0 amp battery
5 and 3 amp Klixon Breakers for the Tasman and the
Microair 760
Aux. Power source Car Cig type plug-in
Bus Bar
Master Switch
PTT Switch
Microphone and speaker
In-line fuses

Anyone out there got any sage advice? Drawings of simple
wiring diagrams they can email me or links to sites?

Wiring, Seals, W&B, Annual and FLY...

Thanks...

Beach

Only one battery not two? If you have two, you can choose if you want
each instrument to be individually switcheable. Battery connectors?
XLRs seem to be the norm in the UK, and all the ones I've seen are
'made-up' with short leads to the XLRs and an in-line fuse and some
duck tape to make sure it doesn't get tweaked. And I've seen a few
gliders with a volt meter to show when the battery starts to fade.

Take a look at the presentations on this topic from the 2007 SSA
convention at; http://www.geocities.com/jhderosa/av...presentations/

As always here are my standard warnings/comments/prognostications...

- You can't just throw anything that seems electrical into an aircraft
and stay legal and/or safe.
- There is no aviation aisle at the local Radio Shack, hardware or DIY
store.
- Know if your ship is standard certified or experimental and
understand what you can do yourself versus what needs to be done or
supervised by an FAA licensed technician.
- Every battery should be fused. If you only have one fuse in the
entire ship, it should be right at the battery.
- Use Tefzel wire throughout. Speaker wire, lamp cord, 14 ga house
wire, and/or doorbell wire (I have seen them all) are not to be used.
Wings and Wheels is a good source for Tefzel.
- While Klixon breakers (and resetable breakers in general) are great
and widely used in powered airplanesl, unfortunately they loose 0.5Vdc
to 1.0Vdc of your battery voltage. Fine if you have a generator
putting out 13.6Vdc but not so wonderful with a fixed power source.
See http://groups.google.com/group/rec.a...a192bb4955aa9b
for more details.

Fly Safe,
John "67" DeRosa

Very Good suggestions. And while you are at it, be prepared to spend
some serious $$ on the proper tools. I use nothing but AMP PIDG
connectors crimped by a genuine APF PIDG Crimp tool. My tefzel wire
is stripped using the correct mil spec stripper( Ideal Industries
Custom Stripmaster(R) Wire Stripper 16-26 AWG wire Item ID:45-1987
http://www.idealindustries.com). Probably near $300 worth of tools
there. Ideally, leave your soldering iron at home.

I have a lot of AGW 20 and 22 in my glider. I spend the money to get
it is WHITE (general use) BLACK (grounds) and RED (power). I am very
capable of mis wiring things, so the red/black is a good visual check
that I don't do something stupod. Most equipment should tolerate some
mis-wiring as long as teh power and grounds are correct.

Look at http://www.aeroelectric.com for some useful tips. His "The
AeroElectric Connection" book is worth the price.

Personally, I think Circuit Beakers look cool, but a standard fuse
holder will get the job done. The only fuses I have blown were on the
ground when I did something stupid. I probably have too many fuses in
my glider and electric systems are a really good place to practice the
KISS theory.

I do have a large (10 A) fuse attached to the + terminal or both of
my batteries. Big enough that I will never blow it with normal load
and small enough that it will blow for some catastrophic problem.

All my switches are SPDT (Single pole, double throw) (http://
en.wikipedia.org/wiki/Switch) with the L1/L2 poles going to Battery A/
B and the COM pole to the device. I can then select what battery each
device (or group of devices) runs off of. I have (2) 12 AH Battery's
and the radio is the big battery killer. If the battery gets low, I
move the radio to the other battery (avoids a power cycle of my
loggers). While on the subject...My switches are the only soldered
connection in my glider and the only place where I have had a wring
failure (due to vibration during trailering over 1000 miles). Proper
strain relief is mandatory for all wiring harnesses.

On Dec 11, 4:59 pm, Todd wrote:
Very Good suggestions. And while you are at it, be prepared to spend
some serious $$ on the proper tools. I use nothing but AMP PIDG
connectors crimped by a genuine APF PIDG Crimp tool. My tefzel wire
is stripped using the correct mil spec stripper( Ideal Industries
Custom Stripmaster(R) Wire Stripper 16-26 AWG wire Item ID:45-1987http://www.idealindustries.com). Probably near $300 worth of tools
there. Ideally, leave your soldering iron at home.

Oh, come on. Do you really think that the low temperature (compared
to near a running engine) and low vibration environment of a glider
requires such expensive connections ?

Todd
3S

On Dec 11, 6:51 pm, toad wrote:
On Dec 11, 4:59 pm, Todd wrote:

Very Good suggestions. And while you are at it, be prepared to spend
some serious $$ on the proper tools. I use nothing but AMP PIDG
connectors crimped by a genuine APF PIDG Crimp tool. My tefzel wire
is stripped using the correct mil spec stripper( Ideal Industries
Custom Stripmaster(R) Wire Stripper 16-26 AWG wire Item ID:45-1987http://www.idealindustries.com). Probably near $300 worth of tools
there. Ideally, leave your soldering iron at home.

Oh, come on. Do you really think that the low temperature (compared
to near a running engine) and low vibration environment of a glider
requires such expensive connections ?

Todd
3S

Oh come on are you kidding? If you really don't know what you are
doing and don't have the right tools then go find a good A&P (or if
the aircraft is certified you'll need one to supervise and sign off
you work anyhow). I'd argue that doing things properly the first time
is not really expensive compared to the cost of downtime, time spend
chasing down problems and safety risks.

If I only I had a dollar for every mangled piece of glider wiring I've
seen... including do it yourself, or certain glider manufactures or
occasionally a clueless A&Ps (but most USA A&Ps I've run into seem to
have higher electrical wiring standards than many glider
manufactueres). Stand around a typical glider port for long enough and
you'll hear people complaining about radio reception, battery life,
transponder operation or some other electrical problems and when you
poke around inside their glider it is often not surprising why.

To start with if you are using those cheap single action crimp tools
you are probably wasting your time - yes it might work now but the
joints are likely not good quality. Crimp connectors need huge
pressure to work properly, think swaging metals together to form a
surface cold weld not just squeezing the connector enough to
mechanically hold onto the wire. You should be using good quality
ratcheting type crimpers with the correct die set to suit the
connector.

There are many reasons to use quality nylon jacketed crimp connectors
besides just heat exposure, they are much stronger and the jacket
resists slipping off better than with PVC jacketed connectors - and
usually the insulators slipping off is cause by damage during crimping
(improper/cheap crimp tools again) and/or excessive handling of the
wiring.

That proper crimp also totally seals the joint against moisture and
moisture related corrosion - that can be an issue in gliders stored in
humid trailers etc. And keep that soldering iron away from crimp
connectors, soldering after the crimp can do damage and pretinning the
wire before crimping is very bad. I completely agree on keeping the
soldering iron at home - as strange as it may seem at first but
properly done crimp connections are more reliable than solder
connections, and they are easier to do.

Like other have said I would not use anything but Tefzel wire
especially in potential abrasion areas such as harnesses that flex
when canopies with attached instrument panels move, etc. Tefzel wire
does require a special stripper for clean strips, you can get away
with a standard high quality stripper at times, but you might be able
to borrow Tefzel one from a friendly A&P. Another good source in the
USA of Tefzel wire is Stein Air http://www.steinair.com/wire.htm
Another reason to use Tefzel aviation wire is it is fully tinned and
much more resistant to corrosion than the usual untinned PVC coated
junk at hardware/auto parts stores.

Darryl

Good comments all around.

- Crimps - multi-action crimpers are better as they apply more
pressure. This goes for lugs as well as coax connectors.
- Solder - Is to be avoided in liu of crimp connectors. However,
sometimes you just can't avoid it.
- Lugs - Always use ring lugs, never spade lugs.
- Wire - Tefzel is the only choice. Why? As mentioned above,
abrasion resistant, fully tinned (so even if abraded there will be no
wire "hairs" to cause shorts), and (most importantly) doesn't give off
dangerous gasses when burning. Tefzel may seem expensive when looking
at $0.20/foot but if you go through 100 feet in a glider I would be
very much surprised. That's $20. Chicken feed.
- Gauges of wire - guidelines (larger is better)
12 to 14 gauge - Main power lead from battery to distribution block
16 to 18 gauge - Power lead from distribution block to individual
devices
18 to 20 gauge - Speaker wiring
20 to 26 gauge - Control wires such as push-to-talk, air brake
switch, etc
- Get you work inspected!



Good luck.

On Dec 12, 11:51 am, ContestID67 wrote:
- Solder - Is to be avoided in liu of crimp connectors. However,
sometimes you just can't avoid it.

Why do you make this statement, John? I've dealt with tens of
thousands of cables professionally for over 35 years, and during that
experience I've found that if a connection is crimped, it's crap. By
that I mean it's highly likely to be either electrically noisy or
mechanically weak.

I did a Google search, and basically discovered that crimping vs
soldering discussions are, in some quarters, a quasi-religious war. I
don't want to add fuel to that fire, but are there authoritative,
unbiased studies (eg, not from connector manufacturers) that bear out
your assertion?

-John

On Dec 12, 11:04 am, jcarlyle wrote:
On Dec 12, 11:51 am, ContestID67 wrote:

- Solder - Is to be avoided in liu of crimp connectors. However,
sometimes you just can't avoid it.

Why do you make this statement, John? I've dealt with tens of
thousands of cables professionally for over 35 years, and during that
experience I've found that if a connection is crimped, it's crap. By
that I mean it's highly likely to be either electrically noisy or
mechanically weak.

I did a Google search, and basically discovered that crimping vs
soldering discussions are, in some quarters, a quasi-religious war. I
don't want to add fuel to that fire, but are there authoritative,
unbiased studies (eg, not from connector manufacturers) that bear out
your assertion?

-John

I'm not sure what sort of cable you are talking about. Some cables
e.g. professional audio cables are probably going to fail regardless
of how they are done just form the handling they get. Similarly I've
spent many hours repairing RF and microwave coax cables in research
labs and I'm sure most failere are from gross abuse (peopel pulling on
the cables etc.) and these have had all times of connections,
soldered, crimped, spot welded, exotic super conducting connections,
etc. For my money in my glider I'll take properly done crimp
connections.

There are quite a few research papers that demonstrate superiority of
crimp connectors in production environments - ie. where both solder
joints and crimp connections are performed properly. Even with good
control and technique solder suffers from dry joints and surface
contaminatation issues amongst others and in general take a lot more
skill to do properly than an equivalent crimp joint. Most of the
papers I recall are in IEEE publications not from vendors, if you are
an IEEE member or have access to their publications I'll try to find
them for you. Crimping may be faster and lower cost in production
environments but automotive and aerospace company also do not want to
pay for the cost of failed connections in the field - if soldering was
superior you would see it being used more in these applications.

It seems many people's experience with crimp connectors is using some
no brand PVC jacketed connector from the local hardware or auto parts
store with a cheap single action crimp tool. All bets are off if that
is the case.

Getting back to the original request, there are some interesting
articles on general aviation wiring etc. at http://www.aeroelectric.com/articles.html
I've not looked through them all but some seem to have a good
perspective from a professional A&P who does this stuff for a living.
He seems to have lots of practical examples of good tools and
workmanship, eg. -

http://www.aeroelectric.com/articles...rimptools.html
http://www.aeroelectric.com/articles.../shldwire.html
http://www.aeroelectric.com/articles/bnccrimp.pdf

Cheers


Darryl Ramm

I would suggest you take a look inside your car. You wont find
anything but crimped connectors EVERYWHERE. And the continue to
function even when corroded by the road salt the local highway
departments love to spread around here.

High quality connectors applied with the correct tool gives a very
reliable and repeatable connector. Look inside your next B787, you
wont find any soldered connectors there either. The technology is
quite well proven.