Baja design landing light wire size

[laz]

I am using the Baja squadron landing lights. I believe the AMP draw is only 3.5 amps per light. What I need to know is what size and type of wire to use. @0 would probably work but not sure.

1. Shielded or not shielded (have Aero LED nav/strobes and they have to be shielded. So should these LED's be shielded. They will be on a Wig Wag circuit also.

2. My attempt for this RV8 is to have no local grounding so I will need to have a two conductor wire.

any help or comments are appreciated.

[rv7charlie]

Originally Posted by laz

I am using the Baja squadron landing lights. I believe the AMP draw is only 3.5 amps per light. What I need to know is what size and type of wire to use. @0 would probably work but not sure.

1. Shielded or not shielded (have Aero LED nav/strobes and they have to be shielded. So should these LED's be shielded. They will be on a Wig Wag circuit also.

2. My attempt for this RV8 is to have no local grounding so I will need to have a two conductor wire.

any help or comments are appreciated.

If you mean 0 AWG, then yeah, I think it would handle it. The wing might not, but no problem with the current.

No local grounding means roughly double the wire size (aluminum airframe can be considered essentially zero resistance).

Lots of calculators, online & off, to tell you what size wire is adequate. I like
http://www.calculator.net/voltage-dr...s=50&x=38&y=15

which assumes out&back (2 conductor) wire; enter 1-way distance. Try to keep voltage drop under 5% for continuous loads. Landing lights could probably stand a bit higher % drop, unless you intend to run them continuously.

Note that 'victims' (intercom, radios, etc) are much more likely to be adversely affected by local grounding than lights, motors, etc. LED's can be 'iffy' due to the switch mode power supplies used in most. But if they work without radio interference in cars using local ground (almost universally the case for cars), then if you have problems in the plane it's likely due to wiring issues on the 'victim' side.

In a plastic a/c, you don't have a choice, but in an aluminum airframe, you're almost doubling your wire weight (and money). Your call, but...

Charlie

[laz]

Sorry for the typo I meant to say 28AWG.

[rv7charlie]

I figured you were joking about the '0'; I was, too.

But 28 awg is way too small, from both a voltage drop perspective (assuming the lights go in the wings), and from a physical strength/durability standpoint. 24awg is just about as low as you can reasonably go when running wire through the airframe, and 22awg is better for durability and typically easier to get with tefzel insulation.

Charlie

[laz]

Man am I getting old or what . Second typo 18AWG . The only28 AWG wire in the plane that small are the darn Ray allen trim wires.

[lr172]

Originally Posted by laz

Man am I getting old or what . Second typo 18AWG . The only28 AWG wire in the plane that small are the darn Ray allen trim wires.

I would check a chart due to length, but I would think that is more than adequate for 4 amps @ 20. Feet

[Jesse]

18AWG should be fine, and I have not had any noise from the Baja Designs lights with unshielded wire.

[tgmillso]

Hi All,

Along similar lines of this thread, what does the impact of local grounding v's grounding back at the firewall have on wire size. I imagine that the resistance grounding locally in an aluminium is much lower than running back through a wire the same size as the positive lead you ran to the device, thus you think this would then impact the size of wire you need to keep the voltage drop below 0.5V for a 14V system. I've crawled through AC43.13-1B and I can't find anything that specifically calls this out. I guess in summary, does the continuous current chart below (from page 11-30) account for a local grounding or a ground return line back to the firewall?
Cheers,
Tom.

[rv7charlie]

You guys really should subscribe to the Aeroelectric list. :-) I asked this specific question on that list several months ago.

Answer: If grounding locally, ignore the return path length. As you suspected, the aluminum airframe 'ground wire' is so massive in cross section, its resistance can be ignored. If using a 'home run' ground wire, include the entire round trip length of wire to compute voltage drop.

Charlie

edit: If you use Google to find a wire size calculator, read the instructions on the web page carefully. Many online wire calculators are written for industrial applications, and some build the return length into the calculator. In those cases, if you're lucky, the instructions will tell you to enter the one-way length.

[lr172]

I use local grounding for everything out in the wing, including the strobe PS and Baja lights. I have no noise issues.

Larry