Received-SPF: pass
 receiver=logan.com; client-ip=72.52.218.78; envelope-from=bob@bob-white.com
Date: Tue, 16 Jun 2009 06:56:53 -0600
From: Bob White <bob@bob-white.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] More Wire Separation?
Message-Id: <20090616065653.292ae80c.bob@bob-white.com>
In-Reply-To: <list-3683860@logan.com>
References: <list-3683860@logan.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit

Hi Chris,

The basic rule is to keep wires that carry a lot of current, especially
when it's switching off and on like the injectors, away from wires with
low level signals and inputs.  Basically keep the wires to the
injectors separate from everything else.  That would include the power
side of the injectors also.  Those leads are not susceptible to noise,
but they generate noise. 

The lead connected to rotor 1 primary injector for rpm and fuel flow
does not carry a lot of current and shouldn't cause any problems.  I
normally tie those two leads (to R1P injector and to EM2) together
inside the backshell of the EC2 connector.  I have plans for a web page
showing how I put the EC2 cables together, but other projects keep
getting in the way.

At some point Tracy changed his recommended injector ground lead
connections from the engine to the airframe near the EC2.  If  the
leads to your "forest of ground tabs" is near, that would provide an
excellent ground point to use.

Bob W.

On Tue, 16 Jun 2009 02:33:05 -0500
Christopher Barber <CBarber@TexasAttorney.net> wrote:

> OK, I think I got separate wire runs for the needed runs to the EC2.  To 
> recap, from what I recall the injector wires should be segregated in a 
> bundle as well as the wires to the coils in a separate bundle.  I 
> believe the wires to the Crank Angle Sensor do NOT need to be bundled 
> separately since they are shielded.
> 
> My question is, when segregating the bundle for the injectors Tracy 
> states to segregate wires 17, 18, 35, 36 & 19 and 37 from the EC2.  For 
> this, does it just include these wires are should the POWER wires for 
> the injectors also be segregated? 
> 
> Also, the one wire that goes from the Rotor One Primary injector to the 
> EM2/engine monitor, should it be segregated along with the other ones 
> since int is connected to the injector?
> 
> Finally, as to wires 19 and 37.  In Tracy version of the wire diagram it 
> shows these two ground wires grounded on the airframe.  He also states 
> that these two wires should be as short as possible.  However, in the 
> alternate wire diagram provided in the manual (the one with the coil 
> wire harness that is in color online), and the diagram that is easier 
> for me to wrap my mind around, it shows these two wires ground to the 
> engine.  To ground to the engine makes it a pretty long wire run.  I 
> cannot ground to the airframe in a composite.  IS IT ACCEPTABLE to 
> ground these two wires to my ground "forest" (the one from B&C per 
> AeroElectric/Bob Knuckles) on my firewall.  This would allow for these 
> two wires to be quite short....from about four feet to about 10 inches.
> 
> Thanks for your patience guys.  Doing this stuff now is much easier on 
> the third or forth attempt <g>.....I gotta do something while waiting 
> for my new "Minstral type" injectors to arrive <g>
> 
> All the best,
> 
> Chris
> 
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:   http://mail.lancaironline.net:81/lists/flyrotary/List.html


-- 
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
3.8 Hours Total Time and holding
Cables for your rotary installation - http://roblinstores.com/