Shielded Strobe Light Wire Questions

[ClayR_9A]

I used molex connectors in my wing roots for nav and strobe wires but wouldn't spend the time doing THAT again. Those wings are never coming off if I can help it, and if they do, cutting and resplicing new connectors will be the least of my worries.

Use butt-splice connectors instead.

-clay

[SteinAir]

OK Guys, this is going to go against everything that's been posted, but here goes anyway.

I'm cleanly against putting any connectors in the wing root. Why?? Several Reasons.

#1) They flatly just are not needed. It's not like you're going to remove the wings on a regular once it's built. Put some conduit in the wing and feeding the wires will be a cinch. I've done this more than once and it works fine, even with a bundle of wires and antenna leads.

#2) It's another point of failure. Whether or not you use Molex, Amp, "Trailer Connectors", etc.. it's still another point of failure to troubleshoot when things get wonky. Short of butt splices, even trailer connections offer lots of areas for intermittent failures. Any of you trailer owners will know what I mean.

#3) Connectors in the root are exposed to more elements than in the plane, etc.. More pins means more surface area to corrode and cause problems.

#4) Shielding. Others have mentioned running the shield throug the connection, and that's ok, but still not as good as just running the complete shielded wire without a break.

#5) Signal Loss. More connections means more signal loss in Autopilot Servo connections, Antenna Leads, Remote Mag Sensors, etc.. Many of these components are sensetive to changes in their feed lines.

#6) No matter what you use it takes a extra time to install these things, then you need to secure them somehow to make sure the pins won't come loose on the wires, etc..

Here's what you do. If you absolutely need to have the wires in the wing before you mount them, just simply coil up the extra 10' and zip tie it to the root rib until you mount the wings. Once they are mounted you're done. If you absolutely MUST have some sort of break in the wing root fairing, do as others have suggested and use a butt splice. They have no pins to corrode, no wire to come loose on the pins, no connection, etc..

Sorry if this note sounds a bit rash, but as many of you know that's my style. I don't mix words, and this is one area that is a pet peeve of mine. Ask yourself if the advantages (what advantages) outweigh the possible future problems.

Cheers,
Stein.

[f1rocket]

Originally Posted by SteinAir

#1) They flatly just are not needed. It's not like you're going to remove the wings on a regular once it's built. Put some conduit in the wing and feeding the wires will be a cinch. I've done this more than once and it works fine, even with a bundle of wires and antenna leads.

I completely disagree. They may not be needed for YOU, but I've had to remove my wings at least twice. Here's are some situations to consider. I like to finish my wings and check the wiring before I get to the airport. Why? Because my garage is heated and my hangar is not. I try to finish the entire airplane at home and troubleshoot the problems there. Second, I fly my airplane the first six months unpainted so I can make any necessary fixes. When it comes time to paint, I have to remove the wings and truck the airframe over to the painter so it will fit in his booth. I don't like to do the same thing twice, that's my pet peeve.

Originally Posted by SteinAir

#2) It's another point of failure. Whether or not you use Molex, Amp, "Trailer Connectors", etc.. it's still another point of failure to troubleshoot when things get wonky. Short of butt splices, even trailer connections offer lots of areas for intermittent failures. Any of you trailer owners will know what I mean.

Properly crimped connections will outlast the airplane. I submit that these extra connections create an very small increased risk of electrical failure. Of course, I have all the proper crimping tools, use excellent connectors, and take care to insulate the connections from water infiltration. For me, the extra work is worth the convenience.

Originally Posted by SteinAir

#3) Connectors in the root are exposed to more elements than in the plane, etc.. More pins means more surface area to corrode and cause problems.

Yes. One must take care to protect the connections.

Originally Posted by SteinAir

#4) Shielding. Others have mentioned running the shield throug the connection, and that's ok, but still not as good as just running the complete shielded wire without a break.

I submit that they are electrically equivilent.

Originally Posted by SteinAir

#5) Signal Loss. More connections means more signal loss in Autopilot Servo connections, Antenna Leads, Remote Mag Sensors, etc.. Many of these components are sensetive to changes in their feed lines.

I really don't know enough about the subject to comment. I don't see any warning in my EFIS or my AP wiring to tell me that I can't add a connector in the middle somewhere. Of course, that doesn't mean that there isn't some signal loss. I guess I'll have to check this out further.

Originally Posted by SteinAir

#6) No matter what you use it takes a extra time to install these things, then you need to secure them somehow to make sure the pins won't come loose on the wires, etc..

Again, you assume bad installation technique. There's no protection from that. I use a bulkhead 12-pin AMP fitting with gold-plated pins. If they come loose, it's because I was a lousy installer. I get what I deserve.

I don't disagree that you add complexity when you add disconnects. However, properly done, I do not think they add any significant risk to your electrical system. I also wanted readers to be aware that there are perfectly acceptable reasons for having such devices in their airplane. To each their own.

[SteinAir]

Good & fair post, Randy. We can agree to disagree, and I can see some of your points as well as the benefits.

You obviously are doing the connector thing better than most. Bulkhead fittings are a good start, gold plated pins are a better solution than tin or silver plated pins (gold doesn't corrode). My point is just that I've seen an awfull lot of crazy type connectors going in wing roots that I wouldn't even use on my car!

If you're going to do it, at least do it right like Randy.

Cheers,
Stein.

[truss]

gathering from what I read....shielded cable should be used for wing wiring...what guage and why the shielded wire in thw wings...somebody educate me to the basics of "aircraft wiring".....not how but materials to use...thx

[f1rocket]

The shielded wire is typically the harness that comes with the strobe units. The Whelen wire loom has a ground wire in it that needs to be continous from the strobe light to the power unit.

As far as your other question, there isn't enough space in this white box I'm typing in to convey all the knowledge to wire an airplane. I'd suggest two books. One is the Aeroelectric Connection by Bob Nucholls. You can find it at http://www.aeroelectric.com/. The other is Firewall Forward by Tony Bingelis. EAA sells them as do many others.

These will give you the basics. You can ask specific questions from there.

[tonyjohnson]

Is it necessary to run the black ground wire from the creativeair power supply to the common ground on the firewall, or do you just ground that wire to the chassis? The instructions say to ground the power supply box to the chassis, but they are unclear as to where to ground the black ground wire from the unit.

Thanks,

Tony

[az_gila]

Quote:
Originally Posted by SteinAir
#1) They flatly just are not needed. It's not like you're going to remove the wings on a regular once it's built. Put some conduit in the wing and feeding the wires will be a cinch. I've done this more than once and it works fine, even with a bundle of wires and antenna leads.


....and from f1rocket....
I completely disagree. They may not be needed for YOU, but I've had to remove my wings at least twice. Here's are some situations to consider. I like to finish my wings and check the wiring before I get to the airport. Why? Because my garage is heated and my hangar is not. I try to finish the entire airplane at home and troubleshoot the problems there. Second, I fly my airplane the first six months unpainted so I can make any necessary fixes. When it comes time to paint, I have to remove the wings and truck the airframe over to the painter so it will fit in his booth. I don't like to do the same thing twice, that's my pet peeve.

There is an "in-between option"....

Have no connector, but put an extra 1 ft in the wire bundle, and coil it up somewhere near the wing root.

For those occasional times (two?) that the wing must come off, just cut the wires. When the wings get re-installed, then you have a choice of either a connector or solder splicing (or crimp splicing) the wires together.

Easier to do initially, final outcome the same if the wing ever comes off....

gil in Tucson

[Radomir]

Tony, ground it locally. I ran it forward..got noise.... got fixed by grounding locally.

Originally Posted by tonyjohnson

Is it necessary to run the black ground wire from the creativeair power supply to the common ground on the firewall, or do you just ground that wire to the chassis? The instructions say to ground the power supply box to the chassis, but they are unclear as to where to ground the black ground wire from the unit.

Thanks,

Tony

[tonyjohnson]

Thanks for the input Radomir. I wonder why you got noise from what would seem to be the proper way. Oh well, go figure. I will ground it locally as you suggest.

Thanks