Brake Lines & Wires In Conduit

[Stabird]

Opinions wanted:

Are there any negatives in running brake lines and electrical wires in the same corrugated plastic conduit? I am planning to use this method to route lines in the center of the floor from the firewall to the front spar bulkhead of an RV6A.
Comments welcomed.


Starbird.

[wildblue37]

Hi Starbird,

Here's a few thoughts on your idea. Remember that conduit is intended to isolate and protect wire runs from chafing and other issues, and adding brake lines adds a separate system and could provide chafing possibilities.

Also, the big-name airframers have design guides which specify separating the various systems (electrical, hydraulic ie brakes, flight controls, etc) throughout the airframe.

Third, I don't know what you plan to use for brake fluid but MIL-H-5606 is flammable with a rather low flash point. Having an electrical short which grounds to the brake lines might cause some issues.

Hope this helps.

wildblue37

[sf3543]

See chapter 11-126. FLAMMABLE FLUIDS AND
GASES.
An arcing fault between an electrical
wire and a metallic flammable fluid line may
puncture the line and result in a fire. Every effort
must be made to avoid this hazard by
physical separation of the wire from lines and
equipment containing oxygen, oil, fuel, hydraulic
fluid, or alcohol. Wiring must be
routed above these lines and equipment with a
minimum separation of 6 inches or more
whenever possible. When such an arrangement
is not practicable, wiring must be routed
so that it does not run parallel to the fluid
lines. A minimum of 2 inches must be maintained
between wiring and such lines and
equipment, except when the wiring is positively
clamped to maintain at least 1/2-inch
separation, or when it must be connected
AC 43.13-1B 9/8/98
Page 11-54 Par 11-126
directly to the fluid-carrying equipment. Install
clamps as shown in figure 11-10. These
clamps should not be used as a means of supporting
the wire bundle. Additional clamps
should be installed to support the wire bundle
and the clamps fastened to the same structure
used to support the fluid line(s) to prevent
relative motion.
You can see AC 43.13-1B at this FAA link: http://rgl.faa.gov/Regulatory_and_Gu...E?OpenDocument
Being experimental, you can pretty much do as you please, but the above provides food for thought.