Eyeball feedthrough for wiring

[pczar3]

In working on the firewall forward, I hooked up a power supply to the main battery feed and the Master solenoid immediately picked up! I shut things down and started checking to see what happened. I knew the Master had to be grounded to pick-up so I checked and sure enough, the wire was grounded. After tracing back to the firewall, I found the insulation split at the eyeball feedthrough. It's not a big deal to run a new wire but I wonder if I am doing something wrong. How do you make sure the feedthrough is tight enough but not too tight? Do you run the wires through some other shield? This is the type I am using. Thanks for any suggestions you can offer.
Paul

 

[RV7 To Go]

I use these from ACS. Expensive but they work fine and make it easy to add wires if needed. They come in different sizes.


STAINLESS STEEL FIREWALL PENETRATION KIT 1 INCH

 

[PaulvS]

In working on the firewall forward, I hooked up a power supply to the main battery feed and the Master solenoid immediately picked up! I shut things down and started checking to see what happened. I knew the Master had to be grounded to pick-up so I checked and sure enough, the wire was grounded. After tracing back to the firewall, I found the insulation split at the eyeball feedthrough. It's not a big deal to run a new wire but I wonder if I am doing something wrong. How do you make sure the feedthrough is tight enough but not too tight? Do you run the wires through some other shield? This is the type I am using. Thanks for any suggestions you can offer.
Paul
View attachment 61559

I think you need a different type of pass through for electrical wiring. Those eyeball fittings are intended for supporting control cables through the firewall. A better option would be as per post #2, or the more traditional split shield with a non-metal grommet to protect the wire, plus fireproof sealant.

Two Piece Firewall Shield - 1/4-Inch Hole | Aircraft Spruce

Two Piece Firewall Shield - 1/4-Inch Hole Two piece firewall shield, 1/4-Inch hole and 3/4-Inch dimple for grommet.

www.aircraftspruce.com

 

[bjdecker]

Use EMT fittings instead of the Eyeball. Use firesleeve and high-temp epoxy to seal it up when done…and leave the set screw off.

 

[Carl Froehlich]

This is what you want: https://store.vansaircraft.com/ff-00001-firewall-penetration-fitting-ff-00001.html
And this to go with it: https://store.vansaircraft.com/ff-00001a-ff-00001a.html

I put one on each side of the firewall for all wires and cables (other than throttle, mixutrue and prop). All the stuff goes through a piece of firesleeve that is inside the penetrator. No chafing and you can seal off the engine side.

This is an RV-14 standard part - but should be standard for all RVs.

Carl

 

[pczar3]

Thanks for the replies. I guess I'll change out those eyeball feed-throughs and protect the wire better.
Thanks again,

Paul

 

[pczar3]

And a follow-up question. Can anyone tell me the dimensions of the firewall wiring feed-through (FF-00001)? The Vans site shows a 1 inch O.D. but I'm trying to figure out if I have enough room for the part sticking forward.
Thanks,
Paul

Thanks for the replies. I guess I'll change out those eyeball feed-throughs and protect the wire better.
Thanks again,

Paul

..

 

[koupster]

And a follow-up question. Can anyone tell me the dimensions of the firewall wiring feed-through (FF-00001)? The Vans site shows a 1 inch O.D. but I'm trying to figure out if I have enough room for the part sticking forward.
Thanks,
Paul


..

That drawing on Van's website looks to be to scale. So about 2/3 of an inch. You'll still need firesleve,etc., so I second Brian's EMT fitting for a pass through.
I suggest using a very thin washer from the same electrical aisle for the teeth on the locknut to bite into. You can install the fitting facing either direction.
Put a layer or two of heatshrink on the wire(s), and then wrap with firesleeve (you may have to slice it lengthwise). Finish with Fire Barrier.

 

[koupster]

You can also use a short length of thinwall steel tubing secured with two pushnuts for smaller wire(s). Shown below before Fire Barrier application.

 

[pczar3]

Once again, this forum to the rescue. Thanks for the information and ideas Koupster. Back to the aviation factory for me!

Paul

 

[koupster]

Once again, this forum to the rescue. Thanks for the information and ideas Koupster. Back to the aviation factory for me!

Paul

Paul,
That heatshrink over the firesleeve is just to cover the sharp ends of safety wire securing the heatshrink (preventing an injury during maintenance down the road).
I subsequently sealed the heatshrink to pushnut gap and the other end of the firesleeve with Fire Barrier. The extended firesleeve acts as a strain relief for those coax cables.

 

[N804RV]

This is what I did for 2awg battery cable and 6awg main buss wire.