Terminal Strips

[JohnBergt]

I was watching some YouTube videos by YouTuber Kitplane Enthusiast who is build a Zenith 750 Super Duty (GASP!!! I know..not a Bearhawk) and he mentioned that he was planning on running all his wiring from the panel to the various endpoints like lights, actuators, instruments, etc to avoid a mess of wires bundled up behind the panel. It got me wondering if you can use terminal strips in airplanes. This way you could prewire your entire panel to these terminal strips, and then connect to all the wires going out to the airframe. Would the fact that a terminal stirp is not generally shielded be an issue? If the terminal strip was secured to say the firewall, and then a small Faraday cage was placed over the terminal strip, would that shield the exposed connectors on the terminal strip from whatever the wire shielding is used for?

[jaredyates]

Yikes, you have me worried, have you had a chance to read any of the Aeroelectric Connection book?

If a wire runs from the light switch on the panel to the wingtip, where does the mess of bundled wires enter the picture? What other way is there to do it?

What is the problem that a terminal strip is going to solve? It will introduce problems of its own, such as needing short circuit protection, concerns about failures such as the screws coming loose, extra resistance, and weight.

The items that need to be shielded are on a short list. Magneto p-leads, audio and mic, and that's about it in most cases.

[JohnBergt]

Yikes, you have me worried, have you had a chance to read any of the Aeroelectric Connection book?

...

The items that need to be shielded are on a short list. Magneto p-leads, audio and mic, and that's about it in most cases.

No, I haven't gotten into the books yet, I am still waaaaaaaaay at the beginning of the education process. I will add it to my list of references to start collecting. Forgive my ignorance with this follow up question then. All the wiring that I see seems to have the extra white or grey insulation/shielding that wraps around the individual wires inside the bundles wire. I assumed, perhaps incorrectly, that this white layer is extra shielding. Seems I may be wrong in that presumption.

[davzLSA]

Hi John, I am a retired electronics technician. In my experience of over 30 years in wiring control panels which is what our instrument panels in the airplane are. I have found that the fewer the connection you can make the more fault resistant your installation will be. Also in a DC system such as ours it is also a good idea to add a filter capacitor to your system. I plan to connect a capacitor to the fuse block. That helps keep any electrical noise out of your wiring. The aeroelectric connections book is also a great resource. I highly recommend it if you have little experience wiring panels. In my installation I am going to use a product from B and C specialties. It is a fuse panel that uses automotive style fuses that indicate if they are open. So that eliminates the terminal strip and a separate strip of breakers. In the aeroelectric connections book it speaks about how if circuit breaker open in flight there is usually a reason and if you reset the breaker all you are going to cause is the wiring in that circuit to heat up and start a fire possibly. So the problem that caused the breaker to open in the first place would need to be found and cleared before resetting the breaker. All this diagnosing and clearing would not happen in flight. An indicating fuse would give the same indication of a fault the same as a breaker popping open.

[jaredyates]

Sorry if my last answer was the tyoe that might discourage asking. Where are you looking at the wires you are seeing, in another airplane?

[JohnBergt]

Sorry if my last answer was the type that might discourage asking. Where are you looking at the wires you are seeing, in another airplane?

no, it wasn't. I think I might not be explaining correctly, but I am referring to pretty much any wires like the ones below. I just grabbed a pic of the internet, not anything specific.

[jaredyates]

Most of the wires that I see in that image are not shielded. Looking at the bottom of the frame, there is a section of red wires, on the left, a section of white wires on the right, and the ones in the middle. Those ones in the middle are likely some shielded audio cables and coax antenna feeds (which are also shielded). The bundles over on the other side of the engine controls are inconclusive, hard to say from this view. Most others look to be not shielded. That's a very complex panel in progress.

[Chewie]

That image you posted is actually a link from this Velocity builder page. See "Instrument Panel" showing what all the components are.

http://rguerra.com/velocity/index.html