Mailing List flyrotary@lancaironline.net Message #46414
From: Al Gietzen <ALVentures@cox.net>
Subject: RE: [FlyRotary] Wire separation?
Date: Sun, 14 Jun 2009 06:58:28 -0800
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>

Chris;

 

Yeah; what Joe said.  Another option in the Velocity is to run some wires through the keel.  Since I chose to separate the wiring to the two sets of injectors and coils from each other to maintain redundancy all the way from the dual batteries; I have one set down the right duct and one set through the keel.  You can get by with less than 6” separation, especially for shorter distances

 

Another way to cancel induction noise is twisted pairs of power and ground leads; or as I chose to do is run the power leads inside a copper pipe (which is inside the right wiring duct), where the pipe is the ground lead. Probably not something you’d like to try at this point.

 

Induction noise is one type; the other is spikes generated in lines by switching inductive loads, like relays and solenoids. These can be filtered by snubber diodes across the inductive load. I was surprised at the size of the spike induced by my staging relay (peculiar to the 3-rotor version) before snubbing.

 

Of course even with all this, you’ll probably recall I had a devil of time with corruption of EC2 settings until we finally added further filtering on the EC2 board.  One possible reason is that I have redundant power leads to the EC2, isolated by diodes at the EC2 since the A/B controller power is common internally.  These diodes will also stop noise in the EC2 from feeding back to the battery.  Never did determine whether that was an issue as we had solved the problem other ways before considering it.  Capacitors across the diodes could eliminate that issue.

 

Best of luck,

 

Al

 

 

 

 

 

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Christopher Barber
Sent:
Saturday, June 13, 2009 2:34 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Wire separation?

 

Since I have had some apparent wire issues I am individually checking

all the wires for my ECU, pumps, coils injectors etc.

 

One of the things Tracy mentions in the wire instructions is to have

some wires (ie those running to the injectors and the coils, IIRC) not

be bundled with other wires.  My question is what does this mean

exactly?  I understand you would not actually tie them together in the

same actual bundle, but, some of the basic path, in my case down the

co-pilot wire tunnel in a larger canard aircraft, has some of these

wires in definite immediate proximity of each other.  Also, of course,

as they meet up at the D-sub connections, they run together for a bit.

 

So, what is the conventional wisdom on the separation of these "noisy"

wires.  Since I am checking them all, and some of wires need to be

pulled out to do so properly, it seems to be the ideal time to make sure

this is done properly and hopefully eliminate one more potential problem.

 

TIA

 

All the best,

 

Chris Barber

Houston

Velocity SE

 

--

Homepage:  http://www.flyrotary.com/

Archive and UnSub:   http://mail.lancaironline.net:81/lists/flyrotary/List.html

Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster